Jeff

Oct 202018
 

I couldn’t stand it. As I looked up from playing my guitar and saw that lovely spool of the new 600V Duelund DCA12GA PolyCAST tinned-copper tone wire, I just had to do something!

The new 600VDC Duelund DCA12GA tinned-copper tone wire!

I decided I really needed to cut a set of 2.5 meter speaker cables off the spool, and then try them as speaker cables connecting my vintage MC30 monaural amplifiers to the Stokowski Altec’s.

I have been using the original Duelund DCA12GA Sn-Cu wire with the baked oiled-cotton dielectric as speaker cables ever since it arrived here (first with the Westminster’s and now with the Altec’s), so I thought it would make for an excellent comparison to drop the new 600V Duelund DCA12GA into the system in their place.

The new Duelund PolyCAST dielectric of the 600V DCA12GA Sn-Cu wire is to the soft and pliable side of life, so it’s easy to imagine it would have effective damping properties on the Sn-Cu conductors, and as a side benefit it makes it flexible and easy to route.

The casing is a little more challenging to strip than the baked oiled-cotton dielectric of the DCA12GA signal wire (which slides off easily), as the PolyCAST hangs on pretty tight. The trick to getting it off without drama is to cut it around its circumference with an X-Acto knife where you want to strip it, then cut the section you want to strip down its length, which makes it easy to peel off.

It’s a little hard to see, but along the side of the casing in gold lettering it says “Duelund Coherent Audio DCA12GA 600VDC CAST Dielectricum Tinned Copper” – a classy touch.

When I hooked up the new 600V Duelund DCA12GA Sn-Cu tone wire between my hot-rodded vintage McIntosh MC30 monaural amplifiers and the Stokowski Altec’s, I oriented the wire so that the way you read the lettering flowed towards the loudspeakers so I could keep the directionality consistent.

The new 600V Duelund DCA12GA Sn-Cu tone wire as speaker cables.

As is my custom, I put the 600V Duelund DCA12GA Sn-Cu tone wire up on Acoustic Revive cable lifts (above).

The new 600V Duelund DCA12GA Sn-Cu tone wire as speaker cables.

Then it was time to warm the vintage McIntosh gear up and listen to a little music. It takes about an hour for the vintage Mac gear to settle in for its full tone, so I caught up on a few things while everything was warming up.

For the first few hours or so the 600V DCA12GA Sn-Cu wire sounded a little rough, which I’ve come to recognize as typical with Sn-Cu wire when it’s fresh off the roll, and then it smoothed out, just as with the other Sn-Cu cables in my experience.

Now fast forward through a few days of listening time. In my Positive Feedback review of the Duelund DCA series of tinned-copper wires in Issue 92 I described the Duelund DCA12GA as … “having a big, rich, smooth, and nuanced presentation” and that’s pretty much what the new 600V version of the DCA12GA sounds like as well, which I would sort of expect given they both use the same 65 strands of 0.25mm diameter tinned-copper wires. 

At the moment, the 600V Duelund DCA12GA Sn-Cu wire sounds a little less airy and spacious than its baked oiled-cotton dielectric brethren, but it’s still early in the run-in period, so that may change as I get more hours on them.

I’m not sure my comparison of the two Duelund DCA12GA wires as speaker cables is all that relevant for the 600V Duelund DCA12GA Sn-Cu wire’s intended purpose, which is higher voltage applications like power cords where you really can’t use the Duelund DCA12GA baked oiled-cotton dielectric wire for reasons of safety, but it’s nice to know that the 600V Duelund DCA12GA Sn-Cu wire still has that great big, rich, smooth, and nuanced presentation of the original DCA12GA with its baked oiled-cotton dielectric .

Depending on your personal aural tastes and the components in your system, you might even prefer the voicing option you get with the 600V DCA12GA Sn-Cu wire as speaker cables, and given it’s about half the cost of the baked oiled-cotton dielectric DCA12GA you might want to order up enough of both to do your own comparisons. 

Ok, that’s it for now, and I’ll report back as I get more time on the 600V DCA12GA as speaker cables, and eventually I’ll try the 600V DCA12GA in power cords, but that may be a while because I’ve got quite a few other things in the queue ahead of it that I have to get done first.

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 5:56 am
Oct 172018
 

In a special mid-week treat for you, it is with great delight that I welcome back Shirokazu Yazaki to the pages of Jeff’s Place to tell us about his latest adventure in Real Sound with his good friend Alan-san!

Yazaki-san (center) with friends in Tokyo.

Welcome back Yazaki-san, and thank you for sharing your latest adventure in Real Sound with us – I loved reading about yours and Alan-san’s adventures!

¸¸.•*¨*•♫♪ ¸¸.•*¨*•♫♪ ¸¸.•*¨*•♫♪

Adventures in Real Sound: Alan-san’s GEC PX25A (DA30) Monaural Single Ended Triode (SET) Amplifiers!

One day in early April in 2016, Alan-san, my best audio friend and also a very eager reader of Jeff’s Place, and I exchanged emails, which led to the start of building up his PX25A mono SET, but it was really a long adventure not only for me, but also for Alan-san, who had waited so long time patiently for the completion of the SET.

Shirokazu: “Recently I have been asked to modify or build up several tube amplifiers, one was the restoration and the modification of Handoko-san’s Marantz Model 7. Handoko-san lives in Indonesia. The other was Harald-san’s request for me to build up a WE310A-DA30 mono SET, just the same as Ookubo-san’s “Altec Green” painted amplifier. Harald-san lives in Switzerland, and was eager to proceed.”

Yazaki-san’s vintage Marantz 7k preamplifier.

DA30 SET monaural amplifier.

Alan-san: “Very good to hear about your ongoing amplifier adventures, they will be very good machines, those two are very lucky people. I was very intrigued when reading about Ookubo-san’s WE310A-DA30 SET. If after finishing building up these two projects and you still have the desire to continue, can I sign up for commission number 3? Please know that this does not require an answer at this point, I was unaware that you were able to build up another “Altec Green.” Please understand that I do not mean to impose on our friendship, so if this is not possible, it is absolutely positively fine.”

Shirokazu: “I personally appreciate your interest in my WE310A-DA30 non-feedback SET amplifier. Surely, I have long felt something healing about the sound of the DA30 SET with the finest and very rich tone. The driver tube, Western Electric 310A, oldest mesh shield, too rare to get would be the best driver tube ever made and also DA30 / PX25A, vintage direct heated power triode, made in England would be something gem, so rare to find out at present, has loftier and more beautiful timbre compared to famous WE300B, I have experienced.”

“And so the amplifier would bring out not only American traditional gorgeous sound of WE310A but also the best virtue of the British made DA30. I believe this SET could offer you this gorgeous sound, with no compromises. The most difficult things for building up the amplifiers would be finding the high-quality output transformer and the very rare vintage vacuum tubes, including the best quality rectifier tubes. Anyways, when I came across the output transformer, the primary impedance 5 k ohm for SET, I could accept your very polite offer. But for your future adventure, you also had better to search for some high efficiency speaker system in a good condition.”

Vintage Altec 832A Corona loudspeakers. Photo by LA Jazz Audio.

About the high efficiency speaker, we immediately started our search. Fortunately, after 3 months of looking, one summer day we came across a pair of vintage Altec 832A Corona loudspeakers in really mint condition, and of course, Alan-san bought them.

Curiously enough, it was surely a coincidence, but I knew from Jeff’s Place that Jeff-san also had just got the same type and color of Altec 832A at the same vintage audio shop in LA in early February in 2018.

Vintage Altec 832A Corona domestic loudspeakers in my main listening room.

(That was an amazing coincidence! By the way, LA Jazz Audio was great to deal with, their shipping was done expertly, and the Altec 832A Corona loudspeakers I bought from them are amazingly musical and beautiful loudspeakers that are somewhat rare these days in the world of Altec vintage loudspeakers. Hint: There’s a beautiful mahogany pair for sale right now on eBay by LA Jazz Audio. It may be your only chance ever to get a mint pair of vintage Corona’s. If I had the extra $ right now I’d buy them myself so I could have Altec’s in every room in my home! – Jeff)

Well, our first adventure of Alan-san’s PX25A (DA30) mono SET, longing and searching for the very best vintage tubes and best suited transformers begun in just this way.

Contribution of “Jean Hiraga-san” to Our Japanese Tube Audio Scene

But now, I’d like to recall to my younger days of early 70’s. When I come into TEAC as a mechanical engineer in 1971, I remember well that Jean Hiraga-san started importer business of dealing with especially European tubes at Kobe in Japan, named “Sansei Enterprise”. For publicity, he offered his imported tubes to the main writers of “MJ”: Asano-san, Morikawa-san, and as I mentioned before, Anzai-san. And so from 1971 or 72, we often saw the articles about them making their own tube amplifiers in every monthly issue of “MJ”.

At that time, the WE300B was already well known among tube enthusiasts as the best triode, but no one knew the name of DA30 (PX25A), PX25.

The PX4, a made in England vintage tube, which Hiraga-san first imported, made Jean Hiraga-san highly influential in the Japanese tube audio scene. Of course, I was so excited to read about such articles on “MJ” and I was really intrigued mostly by the powerful DA30 vacuum tube. Its heater voltage and current was 4V / 2A and 8 W, being bigger than the WE300B at 5V / 1.2A and 6 W, and so we could look to it for more final power. Furthermore, I adored the well-proportioned shape of new dome type of DA30 at one glance, something modern and beautiful. Also, its price of JPY 4,840 was attractive for me as at that price I could succeed in getting a pair for my monthly salary. 

Master Anzai-san’s GEC PX25A Single-Ended Tube Amplifier

The DA30 has one negative point, as to make full use of the true potential of DA30 it needs remarkably high voltage to drive the DA30. A lot of types of circuitry trials, such as using inter-stage transformer between the driver tube and DA30, or power-drive by an EL34 were made public in “MJ” by a lot of well-known writers in almost every issue.

At last, I came across an article by Master Katsutaroh Anzai, using the WE310A to drive the PX25A in a stereo amplifier in the July issue of “MJ” in 1972. I was strongly impressed with his very beautiful circuit with the simplest design, and also his extraordinary passion for and commitment to the WE310A and DA30.

From his articles, I understood well the forceful driving power of WE310A. He managed to bring out over 100 output voltages under the condition of 40 dB gain from the WE310A with his careful study. Also, Anzai-san showed the real frequency characteristic of the WE310A’s output voltage in his articles, so it was very clear about the true potential of its dynamic range and outstanding linearity.

Anzai-san affirmed for us that there might be nothing else like the WE310A, the most powerful driver tube ever made. Really, the heater voltage and current of WE310A are 10 V / 0.32 ampere, and so only from the view point of consumption of heater wattage, 3.2 watt, WE310A would be regarded as a pretty powerful tube. I had some concerns about what the WE310A might sound like, because it was a pentode and not triode.

In my understanding  that the pentode is noted for its higher gain, but on the other hand, its negative factors are the higher internal resistance compared to the triode, and also its tendency to generate harsh odd-numbered harmonic distortion.

I got a hint from Anzai-san’s article about the splendid high range characteristic of the DA30, with the new dome type. For example, the frequency response of WE310A at 20 kHz was -2 dB, and the frequency characteristic of his amplifier’s output was just the same value, -2 dB / 20 kHz. It means, despite of WE310A’s high output impedance, DA30 didn’t have any transmission losses in high-range from the signal level of the WE310A, and that’s without the help of a negative feedback circuit.

These facts would be the true evidence of the DA30’s significant superiority to the WE300B or any other direct heated power triodes, I suppose. 

Well, you might know well the name of Western Electric 91B amplifier, this amplifier, composed of WE274A and WE310A-WE310A-WE300B would be not only a historic vintage amplifier but also it has been regarded as the best single-ended tube amplifier, ever made for some enthusiasts.

In Japan, from the early 70’s, a lot of WE91 type amplifiers, composed of the WE310A and WE300B, and designed with non-feedback circuitry, have been seen in many articles in specialist magazines.

It was common for those kind of WE91 type SET amplifiers that the frequency characteristic declines from -4 dB to -6 dB at 20 kHz. I saw this declination starting from around 5 kHz.

I had thought then, and think so now, that the minimum requirement for the width of frequency response of 20 Hz to 20 kHz is very critical for modern “High-Fidelity” reproduction, so I didn’t accept WE91 type design with the non-feedback circuits.

But why the DA30, especially the new dome type that has such a remarkable characteristic of high range? Are there any reasons?

Yes, the new dome type DA30 has quadrupole construction, which could surely reduce the stray capacitance of each other’s electrical poles, plate, grid and cathode.

I heard that this improvement of high-frequency range of the DA30 had been done in the midst of World War II, and I have no other choice but to recall the historical fact that it was said that England was saved from the invasion of Luftwaffe by the radar arrays on the white cliffs of the Straits of Dover.

Now we can find out that such a leading-edge telecommunications technology in Great Britain more than 70 years ago was made possible by this new dome type DA30 vacuum tube.

The old balloon type of DA30 is a genuine direct-heated triode with a rich low range, but I have felt some darkness in its timbre and a shortage of high-frequencies in this rare power triode.

Of course, it must be come from my personal hearing sense, but I far prefer the new dome type rather than the old type. At the same time, I have known well and comprehended that almost all of the elder writers said the old balloon type of DA30 had deeper sound & timbre, and they liked it.

Anyways, I successfully completed the building up of the DA30 SET without any negative feedback circuit, according to Anzai-san’s design from early February in 1973.

It has been a very huge blessing for me that I have fully enjoyed the sound of the combination of this SET (with continuous modifications over the years),  and my Altec loudspeakers with Onken mid-driver, new 500MT + tweeter, 5000T Esprit, throughout the more than 40 years I have owned it.

I’d like to add one more thing about the superiority of its output transformer, old TANGO FW-50-5S with its big size EI core, that Anzai-san first introduced in his article.

To tell the truth, I haven’t wanted to change my DA30 SET to another type of power amplifier, such as high performance push-pull tube amplifiers with deep negative feedback and their inevitable phase correction, because my very sensitive Onken horn system with 105 dB / W sensitivity could express lucidly every kind of minute artificial “makeup” of its skillful circuitry, I have felt.

There might be another reason too, that being the forceful back electromotive force generated from powerful magnetic circuit with huge Alnico magnet and super lightweight diaphragm, could be far bigger than the usual driver, and have much effect on the amplifier.

Yes, the DA30 SET with no negative feedback circuit doesn’t experience these harmful effects.  I firmly believe, if you want to hear really organic vocals or truly “Real-Sound”, a well and simply built SET that is equipped with fine tubes and a well-suited output transformer, would be the right choice, but of course, you would need to use a high-efficiency speaker like the Altec’s.

Yes, you had better be prepared not to use modern low-efficiency speakers, but hopefully you can find a vintage Altec high efficiency horn speaker system. Such a system could bring out not only nuance-filled vocals, but also you could find out the real and truly stereophonic acoustic guitar sound with sparkling timbre of each string. Once again, I’d like to say, these sounds reproduced through such an SET and the high efficiency speaker would offer you another dimension of live-like feelings from the music.

Well, I imagine, such a system might be exactly what Alan-san has long searched for to his audio life and I only hope, Alan-san’s new GEC PX25A mono SET would have the potential to realize his vision. Alan-san loves music and enjoys playing blues guitar with a vintage tone.

I think there would be a lot of readers of Jeff’s Place who have patiently persevered in their long adventure in pursuing “Real-Sound” just like Alan-san and I have, and so I’d like to share with you the details of Alan-san’s GEC PX25A mono SET in my next articles, the way I actually experienced it.

I’d like to add a postscript that you could see what Mr. Jean Hiraga is up to lately on these web-sites HERE and HERE, which my young friend, Nattawut-san, at the Sentimental Café in Bangkok has informed me of. Thank you so much, Nattawut-san!

Also, I just come upon my master, Anzai-san at Tube Audio Show 2018 in Tokyo, on Oct. 8th. I was so delighted to see him, and to know that he is alive and well.

Well, they are true seniors for me, having introduced me to such a deep and rich world of audio adventure. Thank you very much, Mr. Jean Hiraga and Mr. Katsutaroh Anzai with my heartfelt respect!

¸¸.•*¨*•♫♪ ¸¸.•*¨*•♫♪ ¸¸.•*¨*•♫♪

Many thanks to Yazaki-san and Alan-san for sharing their most excellent adventure with their DA30 / PX25 SET monaural amplifiers, and I can’t wait to read the next installment about their adventures!

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 11:04 am
Oct 152018
 

I know a lot of you have been looking forward to the day when the 600V Duelund DCA12GA tinned-copper tone wire becomes available so you can use it to make DIY power cords, and that day is now here! Woo hoo!

The new 600VDC Duelund DCA12GA tinned-copper tone wire!

Today a spool of 600V Duelund DCA12GA tinned-copper wire arrived from Frederik, and it should be available from Parts ConneXion (for those in North America), and from Hifi Collective (in the UK), in the very near future (I believed it has shipped to them already, but I didn’t see it on their respective home pages when I checked a few minutes ago). To find the Duelund distributor for your particular country you can check HERE.

Frederik tells me that the pricing for the new 600V Duelund DCA12GA is still being finalized, but it should be in the range of about half that of the pricing for the regular DCA12GA, or around $10 USD per meter.

As soon as I find out the actual pricing for the new 600V Duelund DCA12GA I’ll let you know.

Bottom to top: DCA26GA, DCA20GA, DCA16GA, and DCA12GA.

The 600V DCA12GA tinned-copper tone wire uses the same stranded tinned-copper tone wire conductors as the regular DCA12GA tinned-copper tone wire that I wrote about in my review for Positive Feedback in Issue 92, which utilizes 65 strands of 0.25mm diameter tinned-copper wires (top DCA wire in the photo above).

The Duelund 6.6mH CAST Sn-Cu Air Core Inductors utilize Duelund DCA12GA leads.

The difference between the new 600V Duelund DCA12GA Sn-Cu wire and the regular Duelund DCA Sn-Cu signal wire is the new PolyCAST dielectric that was developed to allow for the 600V rating. 

Per the Parts Connexion description, PolyCAST is “… a unique thermoplastic resin composite, which emulates Duelund’s “Signature” CAST process”, which means it is similar to the deluxe CAST damping material that is used in the Duelund CAST capacitors, inductors, and resistor – the black material you see in the Duelund 6.6mH CAST Sn-Cu Air Core Inductors in the photo above.

That means you can now get that great DCA Sn-Cu tone in a 600V DC-rated line of DCA tinned-copper wires that you can be use as hookup wire in electronics where higher voltages are present, as in power supplies (i.e. using the 600V DCA20GA), and now with the 600V DCA12GA that you can use in your DIY power cords.

My first trial using the new 600V version of the DCA12GA will likely be comparing it to the original  DCA12GA version that I use as speaker cables in my main system, which is currently hosting the Duelund-Altec Project loudspeakers, those grand ol’ Stokowski Altec’s.

Stokowski Altec’s in my living / listening room.

That way I’ll be able to give you a better idea how the new 600V DCA12GA compares to the DCA12GA signal wire musically and sonically.

Then at some future point I’ll build up some DIY 600V DCA12GA power cords for my vintage McIntosh MC30 monaural amplifiers and report on that as well. Ditto for a power cord on my Fender Princeton Reverb guitar amp!

I think most of you know I love the tonal qualities that tinned-copper wiring so easily provides, and some of the gorgeous tone of my vintage McIntosh electronics was due to being wired up with tinned-copper wire internally, and if you read my last Duelund-Altec Project post, you know that vintage Altec’s also used tinned-copper wiring internally in their crossovers and to connect to the drivers.

McIntosh and Altec likely used tinned-copper wire during manufacturing for the pragmatic reasons of its ultra-stable electrical performance characteristics and durability over the long term, which really helped them from a reliability standpoint in manufacturing electronics, yet in a bit of serendipity it turns out that tinned-copper also contributed in part of the gorgeous classic tone those two vintage marques are known for.

Ok, that’s it for now. As always, thanks for stopping by, and may the tone be with you!

 Posted by at 4:38 pm
Oct 142018
 

2018 Writer’s Choice Awards for Positive Feedback!

I’ve turned in my Writer’s Choice Awards for 2018 to Dave and David at Positive Feedback, so you’ll be hearing more about that shortly as they’re published.

Here’s a little preview excerpt:

“When I receive the message from Editors Dave and David that it is once again time for Positive Feedback writers to turn in our three Writers Choice Awards for the year, I reflect back on my year in audio, the products I’ve written about for Positive Feedback, and my long-term impressions about them.”

“Having a limited amount of time to write about audio, I choose only to write about audio products that are innovative and that I think have the potential to be truly exceptional, as well as interesting for you to read about.”

“That creates a personal drama for me as I down-select to three from a group of high-performance artisanal audio products that I have written about over the year, which each potentially deserve the recognition of a Writers Choice Award.”

“Let me first recap my 2018 Positive Feedback reviews for you, then I’ll down select, and tell you who my 2018 Writers Choice Awards will go to.”

“The award candidates for 2018 are the Still Audio EL84 Integrated Amplifier (Issue 99), the Soundsmith Zephyr Mk III phonograph cartridge (Issue 98), the First Watt SIT-3 stereo power amplifier (Issue 98), the Soundsmith Carmen Mk II phonograph cartridge (Issue 98), and the Audio MusiKraft Denon DL-103 phonograph cartridge (Issue 95).”

Still Audio EL84 Integrated Amplifier

“The thought that kept coming to mind while I was reviewing the Still Audio EL84 integrated amplifier was “It just sounds like music”.  I really enjoyed my time with the Still Audio EL84 integrated amplifier by Mark Still. The voicing is spot-on for my tastes, with a blend of audiophile-style sonics and musicality that is about as ideal as I’ve ever come across in an amplifier.”

“The parts and build quality of the Still Audio EL84 are superb. I love its Fi-like appearance and artisanal nature. At $2895 USD the Still Audio EL84 is a remarkable bargain for a boutique handcrafted integrated amplifier with a superbly musical balance, and its fine craftsmanship means it’s an integrated amplifier you can treasure for the ages.”

Review: Issue 99

Website: Still Audio

Email: Mark Still

Soundsmith Zephyr Mk III Phonograph Cartridge 

“I love the way that Peter Ledermann has voiced his new Soundsmith Zephyr Mk III phonograph cartridge. The Zephyr Mk III is naturally warm, remarkably musical, sonically excellent, exhibits a vivid musical presence, is dynamically superb, is tonally beautiful, resolves lots of meaningful musical & sonic nuance, and exudes a high quality of construction.”

“I also love the fact that I can get this level of performance from a phonograph cartridge without needing an expensive step-up transformer (SUT) to accomplish it – it’s a satisfying and liberating feeling! The Soundsmith Zephyr Mk III is a bargain at $1500 USD for its über level of musical and sonic performance, and I think you will be mightily impressed by the Zephyr Mk III, just as I was. The Soundsmith Zephyr Mk III easily outperformed my reference SPU phonograph cartridge plus SUT at a fraction of their price.”

Review: Issue 98

Website: Soundsmith

Email: Peter Ledermann

First Watt SIT-3 Stereo Power Amplifier

“Compared to other amplifiers I have heard in my home music and audio-video systems, the $4000 USD First Watt SIT-3 stereo amplifier by Nelson Pass is one of the best, if not the best, amplifier I have ever heard in terms of its artful balance of musicality & sonics, but perhaps most importantly it provided such a clear view into the artistry of the musicians and the emotional impact of their music that it was truly remarkable, and unmatched in that regard by any other amplifier in my experience. The First Watt SIT-3 made me want to get out all my favorite albums just to hear what new musical insights I might discover hidden within their grooves.”

“Is the First Watt SIT-3 the best low-powered amplifier ever? It just might be.  If you think you might want a First Watt SIT-3 of your own don’t wait too long to decide, as they are a limited production item and only 250 of them will be built and offered for sale.”

Review: Issue 98

Website: First Watt

Email: Bryan Stanton (Bryan fields all of Nelson’s email)

Soundsmith Carmen Mk II Phonograph Cartridge

“I immensely enjoyed my time listening to Peter Ledermann’s new Carmen Mk II ($1000 USD), and I can easily recommend it for its enchanting and music lover friendly blend of live-like musicality and well-balanced audiophile-style sonics, which drew me into the music so easily that I quickly set aside my reviewing mindset and just settled into music listening for the sheer joy of the experience.”

“Like the more expensive Soundsmith Zephyr Mk III, the Carmen Mk II has high-output so an expensive step-up transformer (SUT) is not needed. For anyone with a $1000 to spend on a new phonograph cartridge, the Carmen Mk II is the cartridge to buy, and its performance was every bit the equal of my SPU phonograph cartridge plus SUT at one-fifth the price!”

Review: Issue 98

Website: Soundsmith

Email: Peter Ledermann

Audio MusiKraft Denon DL-103 Phonograph Cartridge

“Guy Pelletier’s Audio MusiKraft Denon DL-103 ($579 USD) is a marvel of design excellence and tweak-ability. The fully adjustable Audio MusiKraft cartridge shell that replaces the stock Denon’s flexy flier shell elevates the performance of the beloved classic Denon DL-103 phonograph cartridge to new heights, and allows the listener to adjust its voicing to fit their musical fancy.”

“I think the Audio MusiKraft Denon DL-103 is a brilliant product, and I hope that its powerful tunability features stimulate a revolution in realizing the importance of tunability in achieving one’s ultimate vision of hifi performance.”

Review: Issue 95

Website: Audio MusiKraft

Email: Guy Pelletier

Jeff Day’s Writers’ Choice Awards for 2018

“As always, this year’s reviews have yielded an impressive line-up of artisanal audio products, and I can recommend each and every one of them to you for your future musical enjoyment.”

“Whether it’s Mark Still’s Still Audio EL84 Integrated Amplifier, Peter Ledermann’s Soundsmith Zephyr Mk III or Carmen Mk II phonograph cartridges, Nelson Pass’ First Watt SIT-3 stereo power amplifier, or Guy Pelletier’s Audio MusiKraft Denon DL-103 phonograph cartridge, each of these designers and their artisanal audio products are all worthy of praise and recognition for their lofty accomplishments, and they are tangible proof that high-performance audio around the world will remain vibrant and exciting for years to come!”

“So now for the drum roll announcing my three Positive Feedback Writers Choice Awards for 2018!”

¸¸.•*¨*•♫♪¸¸.•*¨*•♫♪¸¸.•*¨*•♫♪

Ok, that’s it for now. I’ll let you know when Dave and David publish the Positive Feedback Writers Choice Awards for 2018!

As always, thanks for stopping by, and from my home to yours, may the tone be with you!

 Posted by at 1:20 pm
Oct 142018
 

First of all I want to thank you for being patient with me. As some of you know, my Mom, almost 94 years of age now, has been going through some rough times health-wise. Getting her to and from doctors, hospitals, trying to help her out generally, and spending quality time with her has been my priority. That means my available time has diminished for all things music, hifi, and other stuff.

Mom with a Glen Miller and his orchestra album!

As a result my reviews are currently proceeding at a much slower pace than normal (sorry about that to those of you affected), my answers to comments have been briefer, and just everything has slowed down.

So if I forget to answer a question, or my responses to comments seem to be a little short or terse, if I don’t do something as quick as usual or I completely forget, it’s not that I don’t care, it’s just that I am a little overwhelmed right now.

So please be patient with me, and it’s ok to send me a reminder if I drop the ball on something.

A Little Live Music Fun!

I had a couple of good friends and musicians over for a little get-together on Saturday, and it was nice to get in some socializing, as I haven’t been able to get much of that into my life lately.

I fell down on the job and forgot to take photos to share with you, so sorry about that, but I still have some good things to share with you.

Collings family photo: Eastside LC Deluxe (left), Collings Baby 2H (center), and Collings OM2C short scale (right).

It was sure nice to catch up with my friend John April who stopped by for a brief visit to play my Collings Baby guitar (center, photo above), it’s been way too long, John!

John is a multi-talented musician who plays the banjo, mandolin, and guitar superbly, and is a regular in the Badger Mountain Dry Band.

In the video above you can hear a bluegrass version of a nice old gospel song by the Badger Mountain Dry Band they played at a 2010 Benefit Concert at Battelle Auditorium, featuring left-to-right, John April (banjo), Chuck Pedan (guitar), Kurt Gustufson (bass), Joe Smart (guitar), and Jim Honeyman (mandolin).

These guys are really great musicians, and you might recognize Joe Smart on guitar (second from the right) as being a national flatpicking champion on the guitar, or for his Grammy Award with fiddle legend Mark O’Connor, on the Coming Home album. Joe tours as part of the Mark O’Connor Band, so if you are lucky enough to get a chance to catch one of their performances you’ll be in for a real treat!

John was looking to add another smaller Collings guitar to his collection for travel, and brought his Collings OM1 over to play, and compare with my Collings Baby.

John is playing better than ever, and wowed us with his playing on the Collings OM1, Collings Baby, Collings OM2C, and Collings Eastside LC Deluxe for a little while, before having to jet off to another commitment. It was good to see you and catch up, John, and your playing is out of this world!

Listening to the “stock” custom vintage Stokowski Altec’s

Stokowski Altec’s in the listening room.

It was super to catch up with my good friends Ron Barbee, Doc Leo, and Santos Ortega. I wanted to have some fun listening with Leo, Ron, and Santos to the Stokowski Altec’s with their stock crossovers, before I replaced them with the Duelund-Altec Project crossovers showcasing the Duelund CAST tinned-copper crossovers, so we could do a “before and after” listening comparison.

Chad with the Westminster’s and Stokowski Altec’s.

You might remember back a couple of weeks ago when my buddy Chad stopped by for a listening session, and helped me move the big Stokowski Altec’s into my living / listening room.

We put the Stokowski Altec’s into the system where the West’s normally reside, using exactly the same mix of components that I’ve been listening to with the West’s:

  • CTC Garrard 301
  • Ortofon SPU Classic GM MkII stereo phono cartridge (Woody SPU tonearm), stepped up with a bespoke Intact Audio dual mono SUT
  • Soundsmith Zephyr Mk III stereo phono cartridge (Schick tonearm)
  • Duelund DCA20GA interconnects
  • vintage McIntosh MX110Z tuner-preamplifier (with Duelund CAST Sn-Cu caps in the cathode follower)
  • Yazaki-san hot-rodded vintage McIntosh MC30 monaural amplifiers
  • Duelund DCA12GA speaker cables
  • Acoustic Revive RTP-6 Absolute NCF power distributor, connected to wall AC by the exotic new Acoustic Revive Absolute Power Cords that are in for review, a Acoustic Revive RAS-14-TripleC NCF Power Conditioner (on the turntable), a pair of Acoustic Revive acoustic panels behind the speakers, and an Acoustic Revive RR-777 and RR-888 providing a little Schumann conditioning.

After a bit of listening, Chad, a musician (guitarist) and fellow audio enthusiast, told me that he liked the Stokowski Altec’s better than my Westminster’s, which was lofty praise indeed.

The magic Stokowski Altec’s inspired Chad to grab a Collings and sing a very nice version of “House of the Rising Sun”, which was a blast!

I too was impressed with the Altec’s, and felt really silly about not getting them out into the main listening / living room sooner for a listen.

In fact both Chad and I were bowled over by how good those vintage Stokowski Altec’s sounded dropped into the West’s usual place.

It didn’t really seem to matter what albums we played on them, everything sounding amazingly musical and live-like, and “real”.

Stokowski Altec’s in my living / listening room.

I think I now understand better than ever Yazaki-san’s “real-sound” comments about his vintage Altec’s, and why he is so fond of them. Vintage Altec’s can sound amazingly “real” and live-like.

The Stokowski Altec’s completely blew Chad and I away musically with pretty much everything we threw at them during his visit (mostly rock & roll and jazz), and it was completely unexpected that they would demonstrate such excellence, grandeur, and beauty, which left us both in awe at their performance.

I might add that the mix of components supporting the Altec’s for our listening session was period-correct for the kind of components Dr. Stokowski might have used back when the Altec’s were in his home stereo system, and lets just say that Dr. Stokowski had amazingly good taste and his speakers are flat out amazing to listen to even with their stock N-500-D Altec crossovers.

Now back to Ron’s, Leo’s, and Santos’ impressions as we listened to the Stokowski Altec’s.

First I’ll say it was about a 50-50 opinion among us that these vintage Stokowski Altec’s outperformed the Westminster’s in their ability to sound “real” and “live”, which in itself is an impressive achievement, as my hot-rodded Westminster’s are pretty amazing.

All of us recognized the vintage Stokowski Altec’s ability to be remarkably album friendly, making everything from average commercial LPs to audiophile spectacular LPs sound like we were sitting at the recording venue listening to the live performance. I’m not completely sure how the Altec’s accomplish that feat, but they do.

These vintage Stokowski Altec’s excel at presence, dynamics, and tone, which is the “holy trinity” of getting live-like musical reproduction in a home listening setting. They are remarkably real sounding in terms of musical qualities go, like timbre, dynamics, tempo, melody, rhythm, beat, etc., and most importantly musical involvement. They just never put a foot wrong in playing the music, and these Stokowski Altec’s are the most musical loudspeakers I have ever listened to. They also do remarkably well on audiophile-style criteria of resolution, transparency, imaging, soundstaging, soundspace, and the like.

Stokowski Altec’s with my Westminster Royal SE’s for scale – they’re bigger than Westminster’s!

Ron told me he thought the Stokowski Altec’s were the best sounding Altec’s he’d ever heard, and I was glad to hear him say that, because I was thinking the same thing.

I’m really not sure why these particular Stokowski Altec’s sound so good. My components compliment for the Westminster’s clearly suited them well, and there’s nothing particularly remarkable about their own components compliment, which are generally representative of early Altec A7 Voice of the Theatre loudspeakers, with Altec Alnico 803B 16-Ohm bass drivers housed in 825 style bass horn cabinets, Altec Alnico 804A 16-Ohm compression drivers on Altec 511B horns, and Altec N-500-D crossovers.

The only thing I can offer as a possible explanation for their über musical performance is the massive wooden cabinets the speakers were enclosed in to make them domestic-friendly for Dr. Stokowski from an appearance standpoint, the short pedestals that are built into the cabinets that raise them a couple of inches off the floor, and their rather formidable grills, which are not even close to being acoustically transparent and surely do some EQ’ing of the sound.

Stokowski Altec’s in the listening room.

What I can tell you is that these vintage Stokowski Altec’s are the most musically “real” and natural loudspeakers I have ever heard. The vintage Stokowski Altec’s don’t go as low or high in frequency extension as my Westminster Royal SE’s do, but there is something magical about how they play music that I’ve never heard the equal of.

Ron offered me some sage advice: “Don’t screw them up!”

The Duelund-Stokowski Project

These Stokowski Altec’s are in the “forget about audio and enjoy the music forever” category and are so compelling musically that my friends have been asking me if I’m going to replace my Westminster’s with them. They’re that good!

Leo and Santos were already claiming “first dibs” on my Westminster’s in the event they were to go up for sale! Easy boys, easy, not so fast!

Vintage Altec 832A Corona loudspeakers.

As an interesting observation, you might note that Altec probably made these speakers for Dr. Stokowski during the period when their drivers were produced, 1961 to 1964, which would put them at 57 to 54 years old, so Dr. Stokowski would have listened to them in his home for 8 to 11 years before he moved back to London in 1972. During this time period there were lots of good home versions of Altec’s available using their pro drivers and horns, like my superb Altec 832A Corona loudspeakers (above), for example, so it begs the question as to why Dr. Stokowski went to all the trouble to have these speakers built for his home stereo.

Now I know why, as the Stokowski Altec’s are just flat out incredible musical transducers, and easily outperform my vintage Altec 832A Corona loudspeakers (above), and my vintage Altec A5 Voice of the Theatre loudspeakers (below), both of which I love and am crazy about!

Vintage Altec A5 Voice of the Theatre loudspeakers.

Had I listened to the Stokowski Altec’s in my main system earlier I probably would never have even thought of doing anything with their crossovers, because they sound so bloody good the way they are.

So there’s something to be said for serendipity being a friendly ally, otherwise the Duelund-Stokowski Project would have not come into existence.

Ron’s “Don’t screw them up!” echoed in my mind regarding the priceless one-off Stokowski Altec’s, but being the former motocross racer that I am, the motocross credo of “When in doubt, gas it!” overwrote my fears as I go forward with the throttle wide open on the Duelund-Altec Project!

The Duelund CAST Sn-Cu crossover breadboard.

I’m satisfied with the breadboard of the Duelund CAST Sn-Cu crossover I put together on a sheet of GPDS damping material to use as a guide of understanding the layout and wiring requirements, so I proceeded to the next step of cutting some GPDS sheets to fit into the bottoms of the high-frequency horn cabinets of the Stokowski Altec’s.

The GPDS damping sheets mounted into the base of the high-frequency horn cabinets.

I detached the wires from the high-frequency compression drivers, peeled off the backing from the GPDS damping sheets, and then pressed them into place, with their built-in adhesive backs securing them in place.

Here’s another interesting tidbit for you: When I unhooked the N-500-D crossover high-frequency wires from the compression drivers I noticed that Altec used tinned-copper wires in their N-500-D crossovers. The wires are fairly fine in gauge, a guess would be that they are about 20GA, like the Duelund DCA20GA, but I don’t know for sure yet.

No wonder tinned-copper wires sounds so good with vintage Altec’s, that’s what Altec used with them originally! What is old becomes new again!

Laying out the Duelund CAST Sn-Cu components in the Altec high-frequency cabinets.

To start the installation process of the Duelund CAST Sn-Cu crossovers I placed the Duelund components into the high-frequency cabinet of the left loudspeaker to get a rough idea of how much room I had to work with, where to position the components, lengths of DCA wire I’d need, etc.

The Duelund CAST Sn-Cu components sitting in the Altec HF horn cabinet.

I included a couple of different photos from different angles to give you a feel for the amount of space and layout constraints.

Duelund CAST Sn-Cu components sitting in the Altec HF horn cabinets.

My next step will be to wire all of the Duelund CAST Sn-Cu crossover components together for the left loudspeaker, then I’ll do the same thing for the right loudspeaker.

After I get all the Duelund CAST Sn-Cu components in the crossovers wired up correctly, then I’ll remove the back panels of the Stokowski Altec’s and disconnect the N-500-D crossover wiring from the drivers, and then rewire the drivers to the Duelund CAST Sn-Cu crossovers with the Duelund DCA series of tinned-copper wire.

Duelund 600V DCA20GA

To start with I’ll use new 600V Duelund DCA20GA wiring for connecting the Duelund CAST Sn-Cu high-frequency portion of the crossover to Altec Alnico 804A 16-Ohm compression drivers on Altec 511B horns.

I haven’t yet decided which Duelund DCA tinned-copper wire I’ll use to connect the low-frequency portion of the Duelund CAST Sn-Cu crossovers to the Altec Alnico 803B 16-Ohm bass drivers housed in the 825 style bass horn cabinets, but I’ll keep you apprised of my choice as the Duelund-Altec Project progresses.

After I get the Duelund CAST Sn-Cu crossovers completely installed, and the cabinets all buttoned back up, I’ll fire up the system and give it a first listen with the Duelund CAST Sn-Cu crossovers and wiring.

After I make sure everything is working like it’s supposed to I’ll start voicing the crossovers by adjusting their high-frequency balance with the L-pad, and DCA wire choices.

Then as a last step I’ll decide on how I’ll secure all the Duelund CAST Sn-Cu components firmly in place.

I’m not sure how long it will take me to do all that, as this week is going to be a busy one with me taking Mom to see the doc’s tomorrow, and with a surgery scheduled for mid-week. Family will be in town visiting next week, so I probably will not get a lot done next week either.

Stay tuned though, there’s lots more to come!

I had a lot more I wanted to tell you in this post, but it would have made it too long, so expect to see more info in subsequent posts.

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 1:02 pm
Oct 112018
 

Originally I had planned on building external crossovers for the vintage Stokowski Altec’s on the beautifully made Hammond HWCHAS Series Heavy Duty Walnut Chassis With Aluminum Top (HERE).

I thought the Hammond’s aluminum top plate painted in Altec green like the 511-B horns would make for an attractive nod to Altec tradition.

However, the large size of the Duelund CAST Sn-Cu components meant that even the biggest Hammond chassis available were way too small, and ordering custom ones in the size I would need meant that I would have to place a minimum order of 10-15 chassis, so that option was out.

Couch and coffee table for scale in the photo below.

Duelund CAST tinned-copper capacitors, resistors, and inductors for the Duelund-Altec Project.

The more I thought about it, the more I liked the idea of putting the Duelund CAST Sn-Cu crossovers inside the Altec high-frequency 511-B horn cabinet enclosures.

The main benefits of mounting the Duelund CAST Sn-Cu crossovers inside the high-frequency 511-B horn cabinet enclosures are that it would minimize the big Altec’s footprint and open up lots more room placement options.

As a side benefit, with the open back of the high-frequency cabinets I can still easily access the Duelund CAST Sn-Cu crossovers for the inevitable tweaking that will take place, while still being able to gaze upon the impressive and beautiful presence of the Duelund CAST Sn-Cu components. Even after all these years I’m still struck with awe by seeing my Westminster’s Duelund CAST crossovers!

Kramer’s Best Antique Improver, 8 oz.

Over the last couple weekends I did a lot of cleanup work on the cabinets of the Stokowski Altec’s with Kramer’s Best Antique Improver (you can buy it through Amazon), which is probably the most effective product there is for taking good care of your vintage (or new) wood cabinets.

The Kramer’s is very popular for the cleanup and restoration of antique firearms, so it works its magic on both wood and metal parts too (and lots of other things), like the metal exterior of my Altec horns and drivers, for example.

I think I need more Kramer’s!

In the photo below you can see the back of the Altec’s before I used the Kramer’s for cleanup and conditioning the wood.

Stokowski Altec’s before Kramer’s Best Antique Improver.

You wouldn’t believe how much grime and gunk came off the Altec’s when I cleaned the exterior of the cabinets. Well over five decades worth to be exact!

The Kramer’s really did a nice job of cleaning up the wood on the back of the Altec’s too, and I found out after cleaning with the Kramer’s that the cabinet backs were actually veneered with a mahogany color veneer that looks similar (but not nearly as refined) as the mahogany that you see on the back and sides of a Martin D-18 guitar, for example.

My photos don’t do justice to how much better the Altec’s backs look after being treated with the Kramer’s, and now they have a nice vintage glow to the wood that is a huge improvement.

Stokowski Altec HF cabinet enclosure after being treated with Kramer’s Best Antique Improver.

Now that the interior of the cabinets were  cleaned and conditioned I pondered putting the crossovers into the upper part of the cabinet.

It turns out that the 18 1/4 inches by 28 3/8 inches of space available on the inside bottom of the Altec high-frequency 511-B horn cabinet enclosures provides just enough room for the installing the Duelund CAST Sn-Cu crossovers. Fate!

You might remember my past posts about The Soundcoat Company, who has been providing specialized noise control solutions for aerospace, medical, and industrial applications since 1963.

I decided I wanted to use Soundcoat GPDS damping sheets to line the inside bottom of the high-frequency 511-B horn cabinets to give the Duelund CAST tinned-copper components some extra isolation. 

As you would expect, the GPDS is ideal for applications like damping the chassis of audio electronics, so I thought it would be a good match for the Altec’s and Duelund CAST Sn-Cu components.

The Soundcoat GPDS damping sheets are about the thickness of cardboard, but are much more dense and stiff. The top of the GPDS sheets have a hard finish, which is the side that the Duelund CAST components will mount to. The underside has a dense viscoelastic polymer material that damps vibration. The underside also has an adhesive covered by a peel-off backing so that I can stick the GPDS to the cabinet surface to secure it.

Soundcoat GPDS vibration damping sheet in the Altec high-frequency 511-B cabinet enclosure.

I cut sections of the Soundcoat GPDS that were 18 inches by 28 1/4 inches to place on the inside bottom of the Altec high-frequency 511-B horn cabinet enclosures, per the photo above.

The GPDS sheet in the photo above is just sitting there with the backing still on it so I could check the fit, the next step would be to remove the backing and stick it to the cabinet surface.

I also cut out a one-inch wide by four-inch deep slot out of the middle front of the GPDS damping sheets to allow for where the N-500D crossover wires pass up through the 825 style bass horn cabinets to connect to the Altec 804A 16-Ohm compression drivers that are mounted on the Altec 511B horns, and those that attach to the binding posts.

A Duelund CAST Sn-Cu crossover breadboarded on a Soundcoat GPDS damping sheet.

It turns out that the Soundcoat GPDS damping sheets are substantial enough to use as breadboards, so I chose to breadboard the Duelund CAST tinned-copper crossovers directly on the damping sheets I had cut out.

I like securing the leads from the Duelund CAST tinned-copper components – and any point-to-point wiring needed – with McMaster-Carr copper set screw lugs for 14-4 wire gauge (6923K62, $2.04 USD each, HERE).

McMaster-Carr copper set screw lugs are my favored way of making crossover connections because of their pure signal path (wire clamped to wire with no solder), and because they make it easy to swap out wire for experimental/voicing purposes.

Figuring out how to best arrange components for crossovers is a little bit like putting the pieces together for a jigsaw puzzle, you just have to use the circuit diagram as your guide, and move the components around until they fit in the best possible arrangement for the space available.

Duelund CAST Sn-Cu breadboard on a Soundcoat GPDS damping sheet.

In the photo above you can see the low-frequency part of the crossover located on the right 1/3 of the GPDS damping sheet, the other 2/3 of the crossover on the GDPS damping sheet is made up of the high-frequency part of the crossover.

Ok, now that I have the crossover layout figured out, I can proceed to the next step of installing the Soundcoat GPDS damping sheets and the Duelund CAST Sn-Cu crossover components into the cabinets.

Ok, that’s it for now, with much more to come!

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 11:53 am
Oct 082018
 

I really want to thank Frederik Carøe for being so generous as to indulge a resistor idea of mine, and then going way beyond what I imagined to handcraft a truly amazing resistor, which Frederik has humorously dubbed the “Jeffistor”.

The Duelund CAST graphite / Sn-Cu “Jeffistor”.

The idea behind this resistor was a result of my listening impressions while doing trials with various resistors, where I observed some desirable aural traits.

My first aural observation was that I found the musicality and sound of carbon composition resistors more enjoyable than the other types I’ve listened to, like metal film resistors and wirewound resistors, for example.

While those other types of resistors can be nice in the right applications, overall they don’t display the natural “organic” sounding musicality of carbon composition resistors in the applications I have compared them in (preamplifier & amplifier electronics, and crossovers).

My second aural observation was that resistors with smaller gauge number leads (larger wires) tended to have more natural overall tone than those with larger gauge number leads (smaller wires).

This was similar to the result I noted when I wrote the article for Positive Feedback about the Duelund DCA series of tinned-copper wires (HERE), where I observed that: “The smaller-gauge number tinned-copper cables (like the DCA12GA) go from sounding warmer and richer, to sounding brighter and clearer with the larger-gauge number tinned-copper cables (like the DCA26GA).”

Prototype Duelund CAST resistors with tinned-copper leads.

My third aural observation was that the composition of the lead wire makes a difference to overall voicing of the resistor. When I tried identical Duelund CAST carbon composition resisters in my Westminsters’ crossovers, one with pure silver leads, and one a prototype with tinned-copper leads (above), they sounded and performed a little bit differently.

The silver leads had more “sheen” in the upper frequencies, and the tinned-copper leads sounded subtly more relaxed tonally, which I liked. The Duelund CAST carbon composition resistors with the Sn-Cu leads also displayed greater ease dealing with dynamic peaks, which I also liked.

My fourth aural observation was that when I compared two resistors in parallel versus a single resistor of the same value, the tone improved and the sound was more natural when there were 2 resistive elements in parallel.

So when you put all those observations together, my preferences were for carbon composition resistors with dual parallel elements, and with tinned-copper leads with larger a gauge number.

When Frederik and I were talking about the Duelund-Altec Project in early 2018, I shared the above perceptions with him, and asked him if he would be interested in making some resistors with those traits for the project.

Frederik said “yes” and the “Jeffistor” is the resultant resistor.

Duelund CAST “Jeffistors” with three parallel conductive elements and DCA12GA leads.

The “Jeffistor” is a Duelund CAST carbon / Sn-Cu resistor that contains three individual carbon resistive elements in parallel (thus the jumbo sized body), DCA12GA leads (!), and is treated with CAST material for damping in the same way as the Duelund CAST inductors and capacitors.

I must confess I was rather stunned by the sheer size of the “Jeffistor” and with its DCA12GA leads. Frederik never does anything that isn’t impressive in the extreme, and the “Jeffistor” is a case in point.

There are 4 resistor values used in the Altec crossover circuit, as shown above (not counting the L-pad).

R2 Duelund CAST Carbon / Sn-Cu 140 Ohm 10W Resistor

Duelund CAST carbon / Sn-Cu 140 Ohm 10W “Jeffistor” for R2.

We’ll be using the Duelund CAST carbon / Sn-Cu 140 Ohm 10W “Jeffistor” in R2, and they are about six inches long, about as big around as a cigar, and weigh in at a hefty 69 grams, as do the other values of “Jeffistors”.

R3 Duelund CAST Carbon / Sn-Cu 24 Ohm 10W Resistor

Two Duelund CAST carbon / Sn-Cu 48 Ohm 10W resistors.

For R3, two Duelund CAST carbon / Sn-Cu 48 Ohm 10W “Jeffistors” will be connected in parallel to create the 24 Ohm value for R3.

R4 Duelund CAST Carbon / Sn-Cu 100 Ohm 10W Resistor

The Duelund CAST carbon / Sn-Cu 100 Ohm 10W resistor.

For R4 we’ll be using the Duelund CAST carbon / Sn-Cu 100 Ohm 10W resistor.

R5 Duelund CAST Carbon / Sn-Cu 10 Ohm 10W Resistor

R5 Duelund CAST Carbon / Sn-Cu 5 Ohm 10W resistors.

For R5 we’ll be using two Duelund CAST Carbon / Sn-Cu 5 Ohm 10W “Jeffistors” in series to get the requisite 10 Ohms needed.

I should point out that these”Jeffistors” are prototypes, or perhaps I should call them one-off experiments to test an idea about resistors. Whatever you want to call them they are rather amazing to behold!

All I can say, Frederik, is “Wow!”

Frederik has told me that were these to be made available for sale they would be expensive due to the huge amount of hand labor involved in making them, probably in the realm of €150 or thereabouts.

If you really want to get some “Jeffistors” of your own to try you’ll need to contact Frederik directly as they aren’t a production item.

Ok, that’s it for now.

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 3:45 pm
Oct 052018
 

The Duelund-Altec Project is a world’s first for crossovers built exclusively using the new Duelund CAST tinned-copper (Sn-Cu) components (below), and these particular crossovers are currently the only crossovers of their kind in existence, at least for a while, until others start building their own crossovers with the new Duelund CAST Sn-Cu components.

The new Duelund CAST Sn-Cu inductors, capacitors, and resistors for the Duelund-Altec Project.

In the Duelund-Altec Project we will be building crossovers consisting entirely of the new Duelund CAST Sn-Cu Air Core Inductors, Duelund CAST Sn-Cu Paper In Oil Capacitors, the custom Duelund CAST Graphite / Sn-Cu “Jeffistors” (resistors) Frederik made for me, and Duelund DCA Sn-Cu wire, for the historically important vintage Altec loudspeakers that Altec built for conductor Leopold Stokowski to listen to music with at his New York City home, circa 1961 – 1964, before Dr. Stokowski moved back to London to further his recording career in 1972 at age 90.

The Stokowski Altec’s individual components are generally representative of early Altec A7 Voice of the Theatre loudspeakers, with 803B 16-Ohm bass drivers housed in 825 style bass horn cabinets, Altec 804A 16-Ohm compression drivers on Altec 511B horns, and Altec N-500-D crossovers.

The primary difference between production Altec A7’s and the Stokowski Altec’s are the massive wooden cabinets the speakers were enclosed in to make them domestic-friendly from an appearance standpoint, and the accompanying burgundy speaker grills.

Stokowski Altec’s in my living / listening room.

You can read more about the history of the Stokowski Altec’s HERE, but the short version of their history is that Dr. Stokowski listened to music with these custom Altec’s during the period he was conducting the American Symphony Orchestra from 1962-1972 (there’s a great overview of Leopold Stokowski’s life and career that you can read HERE), and then Dr. Stokowski gave the Altec’s to a colleague at the American Symphony Orchestra (one of his conducting students), upon his move to London in 1972.

Jeff (another Jeff!) bought them from Stokowski’s conducting student while living in New York, over 40 years ago now, and then brought the Altec’s with him when he made the move to Seattle to work for Microsoft.

Polishing the Stokowski Altec cabinets with some Kramer’s Best Antique Improver. I think I need more Kramer’s!

Jeff and Lynn decided the Stokowski Altec’s were too big for their condo in Seattle and put them up for sale (photos don’t always give a clear indication of the Altec’s true size, but the photo with me in it for scale above does – they’re big!).

After corresponding with Jeff and Lynn a bit about the Stokowski Altec speakers, my buddy Ron Barbee and I made the trip to Seattle in November 2015 to inspect and listen to them, and after so doing I bought them, and Ron and I made the journey back to my place with the big Altec’s. Thank you Ron, Jeff, and Lynn for such a memorable grand adventure!

I’ve had the Stokowski Altec’s for nearly three years now and I love them, and needless to say I am very excited about showcasing the new Duelund CAST Sn-Cu components in their crossovers, a fitting setting for the world premier of the first set of crossovers constructed entirely of the new Duelund CAST Sn-Cu components!

I can’t thank Frederik Carøe enough for making the Duelund-Altec Project possible by providing all of these beautiful custom and handmade Duelund CAST Sn-Cu components to showcase in the project – you’re awesome, Frederik!

For the Duelund-Altec Project we will be using the following Duelund CAST Sn-Cu components to build crossovers according to the diagram above:

  • Six 6.6mH Duelund CAST Sn-Cu Air Core Inductors for L1, L2, and L3.
  • Two 18uF Duelund CAST Sn-Cu capacitors for C1.
  • Two 10uF Duelund CAST Sn-Cu capacitors for C2.
  • Two 0.82uF Duelund CAST Sn-Cu capacitors for C3.
  • Two custom 140 Ohm 10W Duelund CAST Graphite / Sn-Cu “Jeffistor” resistors for R2.
  • Two custom 24 Ohm 50W Duelund CAST Graphite / Sn-Cu “Jeffistor”resistors for R3.
  • Two custom 100 Ohm 10W Duelund CAST Graphite / Sn-Cu “Jeffistor”resistors for R4.
  • Two custom 10 Ohm 20W Duelund CAST Graphite / Sn-Cu “Jeffistor”resistors for R5.

My last post was the world premier of the new 6.6mH Duelund CAST tinned-copper (Sn-Cu) Air Core Inductors from the very creative mind of Frederik Carøe.

Now with the above background as a prelude, in this post I want to tell you more about the Duelund CAST Sn-Cu paper-in-oil (PIO) capacitors.

Frederik Carøe’s interest in tinned-copper conductors was piqued by my listening trials with vintage Western Electric WE16GA wire (below) that revealed their rather remarkable musical & sonic performance in creating a live-like presentation of recorded music in terms of tone, presence, and dynamics, with a remarkably vivid and engaging overall presentation of the music.

My writing about the Western Electric WE16GA caused a major wave of interest in the affordable (at the time) vintage wire, and the available stocks were quickly depleted.

Closeup: Duelund DCA16GA wire on the right (black), and Western Electric WE16GA on the left (red).

Frederik created a Duelund-style interpretation of the Western Electric WE16GA tinned-copper wire – the Duelund DCA16GA tinned-copper wire – utilizing the same number and gauge of conductors, and an even more purist-style of insulator composed of baked oil-soaked cotton, which offered even better performance than the vintage Western Electric wire.

The Duelund DCA16GA wire became a runaway hit with audio enthusiasts around the world, and shortly thereafter Frederik introduced several more gauges of the Duelund DCA tinned-copper wire that customers had been requesting, the Duelund DCA12GA, DCA20GA, and DCA26GA. You can read the full report about all of these DCA wires HERE.

Then Frederik made the creative leap of using tinned-copper foil to make some prototype Duelund CAST Sn-Cu capacitors.

Back in October of 2016 when I listened to the prototype Duelund CAST tinned-copper (Sn-Cu) capacitors after I installed them into my vintage McIntosh MX110Z tuner-preamplifier’s cathode follower, and the high-frequency section of my vintage Altec A5 Voice of the Theatre loudspeakers’ crossovers, I was absolutely blown away by their performance.

Prototype 0.22uF Duelund CAST tinned-copper capacitor.

The prototype Duelund CAST Sn-Cu capacitors weren’t just good, they were remarkable, and so much better than any other capacitor I’ve tried that the second place capacitor wasn’t even in the same time zone. 

The prototype Duelund CAST Sn-Cu capacitors excelled on the triune hallmarks of live music in terms of tone, presence, and dynamics, as well as being vivid, transparent, natural sounding, and astonishingly life-like in their portrayal of musical qualities of tone, timbre, tempo, rhythm, beat, and the like. As a bonus they also brought a nice boost in performance to those audiophile cherished traits of soundspace, soundstage, and imaging.

I’m not the only one who has been similarly impressed by the Duelund CAST Sn-Cu capacitors either, as Humble Homemade HiFi gave the production version of the Duelund CAST Sn-Cu capacitor the highest rating ever received by a capacitor in their evaluations, which you can read about HERE.

I know a lot of you out there consider Duelund CAST capacitors to be the world’s finest capacitor, and true to form the new Duelund CAST Sn-Cu capacitors are world beaters – they are simply amazing.

18uF Duelund CAST Sn-Cu capacitor.

Personally, I think capacitor history is being made right now by what Frederik and Duelund have done with the CAST Sn-Cu capacitors, they’re that good. What Frederik has done in creating the Duelund Sn-Cu capacitors is truly remarkable.

Let me remind you of the description of how Duelund CAST capacitors are made as told to me by Frederik during the Duelund-Westminster Project, which I lightly edited to replace “pure copper or silver” foils with “tinned-copper” foils for readability’s sake.

The new Duelund CAST Sn-Cu capacitors are made exactly the same way as the pure copper or silver Duelund CAST capacitors used in the Duelund-Westminster Project except that they use tinned-copper foils instead of pure copper or silver foils.

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The Duelund CAST capacitors are the ultimate expression of Mr. Steen Aa. Duelund’s thirty-five years of research into perfecting capacitor design for audio use, and as Frederik has said, “The legacy of Mr. Duelund is to never accept compromise, and that is a principle we proudly uphold in the Duelund CAST capacitors.”

Frederik told me that many capacitors today use an insulating plastic film as the dielectric because it makes them inexpensive to produce, but the problem with using plastic is that it noticeably degrades the audio signal, “With plastic you get what Steen would describe as an echo, masking the real details of the signal”.

18uF Duelund CAST Sn-Cu capacitor.

So in the Duelund CAST Sn-Cu capacitors, like the pure copper and silver foil Duelund CAST capacitors, Frederik doesn’t use any plastic, but rather only annealed tinned-copper foil in natural paper and oil, along with resonance control both inside and outside the capacitor.

A capacitor is made using two foils with paper between the foils, which results in capacitance being created in the electric field between them.

Each Duelund CAST Sn-Cu capacitor is completely hand crafted in an incredibly labor intensive process:

“Foils of tinned-copper are initially wound with paper to a certain value that is a good deal over the needed capacitance. Then the foil is put under vacuum pressure in an oil tank at high temperature for about a week, so that everything inside the winding undergoes vacuum impregnation and is permeated by oil.”

“When this process is done, the resulting foil is wound by hand in a humidity and temperature-controlled room to an exact specification, and then it is placed back into the oil.”

“Immediately after this process the winding is sealed by the use of a special lacquer, which is also used in the yacht industry to seal against moisture. This takes another week. During this process a ring of vacuum impregnated paper has been readied with a base of our CAST material.”

“The winding is heated and then placed in the ring & base assembly and CAST material is poured on top of it in five stages, with air bubbles in the CAST material being forced out by applying a very precisely controlled flame to the surface (yes really!). This process takes another week. Following this step the capacitor is measured and checked (as it has been at every step along the way), and if everything is ok, then we ship it to the customer. The total production time is typically six to eight weeks.”

The CAST base of the 18uF Duelund CAST Sn-Cu capacitor.

Other than their obvious high quality, one of the most striking aspects of the Duelund CAST Sn-Cu capacitors are their large size and heavy weight, which is due to their perfectionist design using natural materials and Sn-Cu metal foil – they simply have to be larger than mass produced capacitors using this approach.

18uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for size comparison.

Frederik says the careful selection of materials and the Duelund no holds-barred style of design provides dramatic benefits for audio applications:

“From a performance standpoint, the main thing is an absolute lack of coloration, and a much more natural presentation – things don’t float around but stay locked in time and space. How you perceive and understand the layers in the music becomes greatly enhanced, primarily because of the sudden silence in between notes. Micro and macro dynamics take on a whole new meaning. Mr. Duelund would liken it to drinking Coke your entire life and then suddenly having a drink of pure water.”

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Stokowski Altec’s in the listening room.

As mentioned earlier, in the Duelund-Altec Project we are using the new Duelund CAST Sn-Cu capacitors in positions C1 (18uF), C2 (10uF), and C3 (0.82uF) of the Hiraga-inspired crossovers for the grand ol’ vintage Altec’s (above) according to the modified Hiraga-style crossover (see schematic below).

Duelund CAST Sn-Cu 18uF capacitors for C1

18uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for size comparison.

Each Duelund CAST Sn-Cu 18uF capacitor is 7 1/4 inches across (18.42cm), 2 inches tall (5.1cm), and weighs 2478 grams (5.47 pounds).

All of the Duelund CAST Sn-Cu capacitors used Duelund DCA16GA tinned-copper wire for leads.

To give you a better idea of the size I’ve shown the Duelund Sn-Cu capacitors with an 8 ounce coffee cup for a size comparator.

18uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for a size comparator.

I photographed the 18uF Duelund CAST Sn-Cu capacitors from a few different angles so you could get a better idea of what they look like.

CAST base of the 18uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for a size comparator. Notice the leather-like texture of the CAST base material.

18uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for a size comparator.

Duelund CAST Sn-Cu 10uF capacitors for C2

10uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for a size comparator.

Each Duelund CAST Sn-Cu 10uF capacitor is 6 inches across (15.24cm), 1 1/4 inches tall (3.18cm), and weighs 1309 grams (2.89 pounds).

10uF Duelund CAST Sn-Cu capacitor with 8 oz. coffee cup for a size comparator.

10uF Duelund CAST Sn-Cu capacitor shown with 8 oz. coffee cup for a size comparator.

CAST base of the 10uF Duelund CAST Sn-Cu capacitor shown with 8 oz. coffee cup for a size comparator.

Duelund CAST Sn-Cu 0.82uF capacitors for C3

0.82uF Duelund CAST Sn-Cu capacitor shown with 8 oz. coffee cup for a size comparator.

Each Duelund CAST Sn-Cu 0.82uF capacitor is 2 7/8 inches across (7.3cm), 3/4 of an inch tall (1.91cm), and weighs 153 grams (0.34 pound).

0.82uF Duelund CAST Sn-Cu capacitor shown with 8 oz. coffee cup for a size comparator.

0.82uF Duelund CAST Sn-Cu capacitor shown with 8 oz. coffee cup for a size comparator.

I hope the descriptions and photos gives you a better feel for what these Duelund CAST Sn-Cu capacitors are like.

Pricing for the Duelund CAST Sn-Cu PIO capacitors is similar to the pricing of the Duelund CAST pure copper foil PIO capacitors, being just a bit more to account for the more expensive tinned-copper foil used in them, but I don’t have any firm pricing information yet. 

For example, a 16uF Duelund CAST copper foil PIO capacitor’s MSRP is $1899 USD, and a 20uF Duelund CAST copper foil PIO capacitor’s MSRP is $2358 USD, so if you split the difference you get a MSRP of about $2128 USD for an 18uF Duelund CAST copper foil PIO capacitor.

A 10uF Duelund CAST copper foil PIO capacitor has an MSRP of $1268 USD, so the 10uF Duelund CAST Sn-Cu would be slightly more expensive than that.

That should help give you an idea of costs.

Ok, that’s it for now, there will be much more to come!

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 9:22 am
Oct 042018
 

I thought I’d follow the same basic progression for introducing the Duelund-Altec Project to you as I did for the Duelund-Westminster Project, where I discussed each Duelund CAST component in detail, then detailed each step as I breadboarded the crossovers, modified the loudspeakers, and then constructed the final version of the crossovers, followed by updates of any DIY refinements or tweaks I discovered along the way.

6.6 mH Duelund CAST Sn-Cu Air Core Inductor.

In this post I want to tell you more detail about the Duelund CAST tinned-copper (Sn-Cu) Air Core Inductors that I’ll be using in the Duelund-Altec Project for the grand old Stokowski Altec’s crossovers as shown in the photograph above, and as depicted in blue in positions L1, L2, and L3 in the crossover digram below.

An inductor (also called a choke) is a passive device that stores energy in its magnetic field (a capacitor stores energy in its electric field, for example).

6.6mH Duelund CAST Sn-Cu Air Core Inductor.

The Duelund CAST Sn-Cu Air Core Inductor – as the name implies – utilizes an air core that annealed soft tinned-copper foil in natural paper and oil is wrapped around, instead of being wrapped around a magnetic core as with many other inductors.

The 6.6mH Duelund CAST Sn-Cu Air Core Inductor is one paper-in-oil (PIO) foil coiled up, and is a passive device that stores energy in its magnetic field.

To construct a Duelund CAST Sn-Cu Air Core Inductor a foil of tinned-copper is initially wound with paper around an air core to a certain value of inductance that is greater than the needed inductance (which is 6.6mH in this case).

Then the coiled Sn-Cu foil is put under vacuum pressure in an oil tank at high temperature for about a week to permeate everything with oil. Then the Sn-Cu foil is coiled by hand in a humidity and temperature-controlled room to an exact inductance specification, and then it is placed back into the oil. Immediately after this the winding is sealed with a special lacquer that takes a week to cure.

During this process a ring of vacuum impregnated paper has been readied with a base of CAST material (above).

6.6mH Duelund CAST Sn-Cu Air Core Inductor.

As you can see in the photo above the completed CAST base has a leather-like surface texture.

Then the coiled foil is heated and placed in the ring & base assembly and CAST material is poured on top of it in five stages.

A precisely controlled flame is then quickly applied over the surface to drive any air bubbles out of the CAST material (the black glossy material you see in the photo below).

6.6mH Duelund CAST Sn-Cu Air Core Inductor.

Following this step the Duelund CAST Sn-Cu Air Core Inductor is measured and checked against controls to ensure quality. The total production time is typically six to eight weeks to make each inductor.

Each 6.6mH Duelund CAST Sn-Cu Air Core Inductor is 7 inches across (17.78cm), 1.5 inches tall (3.81cm), and weighs 3257 grams (7.18 pounds) – they’re big and heavy!

The leads are Duelund DCA12GA tinned-copper wire.

The leads are Duelund DCA12GA tinned-copper wire.

Frederick told me, “As far as I know, the Duelund CAST air core inductors are the only paper-in-oil inductors commercially available to this day.”

Frederik pointed out to me that many people mistakenly think inductors aren’t as important as other circuit components because they typically deal with lower frequencies.

He said, “In fact it’s the total opposite, the lower registers are far more resonant in nature than high frequencies, which means resonance control becomes even more important. People are always slow to try the inductors, but when they eventually do, they are always amazed at the difference.”

Final pricing for the new 6.6mH Duelund CAST Sn-Cu Air Core Inductors is not yet available, but I will provide it for you as soon as it becomes available.

Frederik told me regarding pricing, “The inductors, I do not know – but should be slightly more than the regular CAST Cu inductors due to the more expensive foil.”

To give you an idea of pricing, for example, a 5mH pure copper foil Duelund CAST Air Core Inductor MSRP is USD $1,779, and can be ordered from Parts Connexion for  USD $1,513, so an equivalent Duelund CAST Sn-Cu Air Core Inductor would be a little more.

A 6.6mH Duelund CAST Sn-Cu Air Core Inductor would be more expensive than that by several hundred or so USD, I suppose.

Many thanks to Frederik for making the Duelund-Altec Project possible by providing all these beautiful custom and handmade Duelund CAST components for the project – you’re awesome, Frederik!

The Duelund-Altec Project is a world’s first for crossovers built exclusively with the new Duelund CAST Sn-Cu components, and are the only ones in existence at this time.

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 10:44 am
Sep 302018
 

Duelund 600V DCA20GA

I wanted to give you a heads up that the new Duelund 600V DCA20GA tinned-copper tone wire is now available at Parts Connexion.

The price of the 600V Duelund DCA20GA is $5.99 USD per meter, but is on sale now for an introductory period for $3.99 USD per meter.

The 600V DCA20GA tinned-copper tone wire uses the same stranded tinned-copper tone wire conductors as the regular DCA20GA tinned-copper tone wire that I wrote about in my review for Positive Feedback in Issue 92, which is constructed using 26 strands of 0.15mm diameter tinned-copper wire.

Until now, all of the Duelund DCA tinned-copper tone cables / wires used the same oil-soaked and baked cotton dielectric, but Frederik at Duelund also wanted to add a 600V DC-rated line of DCA tinned-copper wires that could be used as hookup wire in electronics where higher voltages are present, as in power supplies, for example.

The new 600V Duelund dielectric that Frederik developed is called PolyCAST. Per the Parts Connexion description, PolyCAST is “… a unique thermoplastic resin composite, which emulates Duelund’s “Signature” CAST process”, which means it is similar to the deluxe CAST damping material that is used in the Duelund CAST capacitors, inductors, and resistors.

The new Duelund 600V DCA20GA for use as hookup wire in wiring components internally.

Frederik sent me some of the new Duelund 600V DCA20GA tinned-copper tone wire to try in various applications, so I’ll be reporting on that as I get a chance to try it.

I’ll be giving the Duelund 600V DCA20GA tinned-copper tone wire a try in the Duelund-Altec Project that is in the works now, and I’ll likely try making some interconnects with it, as I am also curious how it sounds as a lower-voltage signal cable.

Also, very soon the Duelund 600V DCA12GA tinned-copper tone wire will be available, so I’ll let you know as I hear more about that.

Ok, that’s it for now!

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 6:03 am