May 272017

In my earlier blog post I introduced Mr. Shirokazu Yazaki to those of  you who are new to Jeff’s Place, and for the rest of you Yazaki-san needs no introduction, as you have been following the illuminating audio adventures with Yazaki-san for quite some time now.

Left to right: Ishimi-san, Jeff-san, and Yazaki-san.

I met Yazaki-san back in early 2015 while I was preparing the article about the Spec RSA-M3 Real Sound Amplifier for Positive Feedback, and our conversations and audio ‘adventures’ since then have completely changed the way I think about audio and music reproduction in the home.

Whenever I think upon what Yazaki-san has told me about music & audio over the last few years, and his ‘real sound’ approach to his own audio system, I am rather amazed by his wisdom for all things audio and music.

What I learned from Yazaki-san about voicing equipment with capacitors, resistors, and tinned-copper wire for ‘real sound’ was revelatory for me, and that knowledge has empowered me to pursue audio adventures with my own audio equipment that has brought them ever closer to my interpretation of ‘real sound’ in my home, resulting in what has surely been the most enjoyable & satisfying time that I have ever experienced in this wonderful audio hobby!

Yazaki-san’s vintage Marantz 7k preamplifier.

Yazaki-san has been so kind as to write an article for us, My Adventure With My Old Marantz Model 7

In Part 1 of Yazaki-san’s article, he told us about his near forty year passion of pursuing ‘real sound’ with his vintage Marantz Model 7 preamplifier, and the resulting enjoyment & satisfaction that pursuit has brought to his life.

Yazaki-san also shared his thoughts with us about several brilliant design aspects of the Marantz Model 7, and how its design allows it to still hold its own against, or even surpass, anything made today in musical ‘real sound’ terms.

Yazaki-san told us about his approach to fine-tuning its performance for ‘real sound’ through a careful selection of internal parts like capacitors and resistors, and finally, hinted at the modifications he was going to tell us about in Part 2 of his article that would take the Model 7’s performance to an even higher level.

There’s a number of things that Yazaki-san said in his article that particularly impressed me (and I will elaborate upon them even more in the future), but for now let me mention one, the lengthy span of time that he has enjoyed listening to his Marantz Model 7 in his home system, nearly forty years!

There is a tendency for quite a few of us involved in the audio hobby to change preamplifiers, amplifiers, and loudspeakers, for example, in a continuous effort to achieve a combination of musical & sonic performance in our home hi-fi systems that we can truly enjoy.

This ‘equipment merry-go-round’ approach to obtaining a satisfying musical balance is only occasionally successful, is very expensive, and often leads to frustration & disenchantment with what is otherwise a wonderful hobby of listening to the music you love at home, not to mention the unwanted friction with a significant other that the ‘equipment merry-go-round’ sort of approach to the hobby can create.

Contrast that to Yazaki-san’s approach of making careful onetime choices of a preamplifier, an amplifier, and loudspeakers, for his home hi-fi system, that have provided him a lifetime of satisfaction, and with the added bonus of enjoying the ongoing adventure of subtly voicing them until they perfectly align with his sensibility for Real Sound. 

Altec and Onken.

I think there’s a number of benefits to Yazaki-san’s approach to home audio, the first being that it minimizes major equipment costs over a lifetime of musical enjoyment, while leaving more money for building a library of the music you love.

Yazaki-sans approach also provides a continuing source of entertainment, enjoyment, and satisfaction for the audio hobbyist at a relatively modest cost, while optimizing performance with a few well-chosen capacitors, resistors, or lengths of wire, or to implement a few simple ‘hot-rod’ modifications here and there, during your audio adventures.

Also, as Yazaki-san has said, this approach rewards the music lover in deeper and more long term ways, because like a fine bourbon, the musical & sonic flavor of components improves as the years go by, for those who are patient enough to let time and the flow of electrons have its way with their hi-fi components.

Yazaki-san’s approach is a level of audio wisdom that I am just starting to fully appreciate and understand the importance of, and something that I am learning to incorporate into my own audio experience.

Now, without further ado, here’s Part 2 of Yazaki-san’s article about his life with the Marantz Model 7k – enjoy!


My Adventure with My Old Marantz Model 7k

Part 2: My Way of Modification

Dedicated to Saul B Marantz and Sidney Smith for their true masterpiece!


Shirokazu Yazaki

Strengthening the Power Supply and the Addition of Decoupling

Half-wave Rectification and Diodes

It might be needless for me to tell you how important the quality of the power supply is, and it would also be true for +B rectification of the Model 7, because the current from the power supply turns into the signal current itself.

There are two major points to the quality of the power supply, one being the noise figure, and the other being the speed of the current from the power supply.

The noise figure decides the noise level of the signal current, and it mainly owes to the characteristic of the diode used for rectification, and the current speed much depends on the characteristic of the capacitor installed into the power supply.

Please take a look at the figure “Comparison of Tube Preamplifiers” by Kato-san, my best friend throughout 40 years.

You can see that the +B rectification scheme of the Model 7 is half-wave (one Selenium diode).

Compared to full-wave rectification, the wave height of the half-wave after rectification is lower, and it means the efficiency of rectification of the half-wave has no advantage to full-wave rectification.

So why did the design geniuses at Marantz decide to adopt half-wave rectification? I can only imagine, but surely they made a hearing comparison test of half-wave to full-wave rectification, and decided to adopt half-wave rectification.

Half-wave rectification needs only one diode, full-wave rectification consists of two diodes, and the diodes (including the Selenium diode) inevitably generates switching noise at some level in the signal spectrum.

You and I could easily reach the conclusion with this qualitative example, that the noise level for two diodes would be higher than for one diode, and that the noise spectrum of the two diodes could be wider than with one diode.

About 10 years ago I heard directly from Atarashi-san, a main writer for “Tube Kingdom”, a Japanese specialist magazine for tube amplifier enthusiasts, who is an authority on vintage tubes, that he preferred the sound of half-wave rectification rather than the full-wave rectification.

His witness might be additional evidence for the superiority of the sound of half-wave rectification, I suppose.

The Marantz designers are worthy of respect for their decision to select half-wave +B rectification for the Marantz 7, I believe.

Well, I have tried and experienced a lot of types of diodes and bridge diodes, including the vintage silicon bridge by Western Electric that was used for telephone exchange machines, as well as many types of the latest SiC SBD’s (Schottky Barrier diodes).

I confirmed each diode had a different characteristic sound, and it was beyond my imaginings that they would be so different.

Ten years ago when I became involved in the Class-D solution by International Rectifier, LA (now Infineon Technologies), my quest for an excellent sounding diode was accelerated.

When I searched for the diode for our then top of the line Class-D amplifier, the RSA-F1,  I knew from the literature that the Ultra-Fast & Soft Recovery type diodes were cutting edge, and they had been developed to meet the demands of industrial use for getting higher efficiencies from power supplies, and for reducing radiation from the switching noise itself.

But as I said earlier, each diode has its own unique tone for audio purposes, even if it is of the Ultra-Fast & Soft recovery type. Fortunately, I came across a diode with almost perfect characteristics, the STTH6112TV2, in early May of 2010.

I have known well that it was said that the Selenium diode, which was used in the +B power supply, could only provide the musical sound of the original Model 7.

I wondered what the sound differences would be between the Selenium and the Ultra-Fast & Soft Recovery STTH6112TV2.

I got potent evidence from my young friend, Nattawut-san in Bangkok, Thailand. He and his friend, Tanawat-san, started a restoration business for vintage audio products 3 years ago, and they already have gotten a lot of experience with modifications using the STTH6112TV2 in place of the Selenium diode.

He said to me, “The STTH’s sound is more transparent, with lower noise, and the tonal balance seems real, as it should be. I think Selenium’s sound seems sweet because of its higher noise, and that it would add its own character to the sound”.

I fully agree with his impressions of the STTH6112TV2. I can feel the huge & clear sound stage, and the outstanding flat energy balance from the high-range to the richest low-range, with this STTH6112TV2.

Fortunately enough, I have experienced the WE274B engraved vacuum tube rectifier for three years now, and it is often called the Holy Grail for rectifiers, and I have also been using the Marconi U52 (GEC, Osram), the best vacuum tube rectifier I have ever heard.

A little bit figuratively speaking, I feel the sound of the STTH6112TV2 comes very close to those high-quality direct-heated rectifiers, and it could surpass the sound of indirect heated rectifier tubes like the GZ34 and GZ37.

The STTH6112TV2 is nearly free from switching noise so that we could enjoy the virtue of the diode with not only half-wave rectification, but also with full-wave and bridge rectification.

Anyway, I would like to say to the Model 7 lovers out there that are searching for NOS Selenium rectifiers, that I think you can receive the full benefit of the latest progress in science and technology in rectification with the STTH6112TV2.

Also, please consider that the NOS Selenium diodes are now difficult to find, and furthermore they were made from a toxic substance – Selenium – which is best avoided from a health and safety standpoint.

I believe that by using the STTH6112TV2 in place of the Selenium diode, that you could experience another level of sound quality from your Model 7, and be able to receive the full measure of real musicality that the Model 7 is known for.

Capacitors for the Power Supply

When I build up the traditional power supplies for my tube amplifiers, and also for my Class-D amplifiers, I install a hermetically sealed oil-filled capacitor into the subsequent stage of the rectifier tube or diode, connected in parallel with the main electrolytic capacitor for rectification, and its addition provides a more responsive and organic sound.

As you might imagine, the addition of a 0.22~0.47 oil-filled capacitor in this position improves the sound dramatically, addressing the sonic weaknesses of the electrolytic style of capacitors, I suppose.

This improvement could be explained through the measured value of E.S.R. (Equivalent Series Resistance) for the higher frequency range, for example, at more than 10 kHz, for the oil-filled capacitor and the electrolytic capacitor.

Actually, the E.S.R. value of an oil-filled capacitor in the higher range is much lower than with an electrolytic capacitor. E.S.R. would be regarded as the inner electrical resistance of the capacitor, and so it could be expressed as the speed of the current from the capacitor. But we can’t explain the sound differences with only the value of E.S.R.

Generally, the latest PP capacitors (metalized polypropylene capacitor) are proud of their lower value of E.S.R. compared to hermetic seal oil-filled cap, but their sound and tone is far different when compared to the oil-filled capacitor.

When we connect capacitors in parallel with an electrolytic capacitor, I much prefer the sound of the oil-filled capacitor because of its organic tone, which is so sweet & beautiful to my hearing, and I suppose almost all of the readers of Jeff’s Place would like the tone of hermetic sealed oil-filled capacitor too. I would like to express the reason why this is so in the article about the coupling capacitor a little later on.

Well, the way of installing an oil-filled capacitor for signal use on the way out of diode or rectifier tube of your power amplifier could be also very effective for improving the tone and the sound, and so I strongly recommend it to you.

Let’s consider that the +B current of the power amplifier directly turns into the driving current for the speaker through the output transformer. A more powerful current with higher speed, flowing through the voice coil, could change the tone of the speaker in a desirable way.

Well, we can hear these sound differences in one listening session, but we don’t have any measurement methods suitable for such a dynamic current moving at high speed to help explain why it sounds better to our ear, so our hearing sense is our best method of measurement at present, I think.

You can see the photos above for one example for strengthening the power supply.

I had completed the restoration & modification of an original Model 7, Serial No. 7-17752, about one year ago at the request of Handoko-san, who lives in Surabaya.

You can see Handoko-san’s listening room below. What an enthusiastic music lover Handoko-san is!

In the power supply modification photos above (left), you can see the bridge diode for the heater of the ECC83 (12AX7) I used for the Model 7. The ECC83 is an indirectly heated tube, so you don’t have be too nervous about seeking out a high-quality bridge diode, I think.

But for the peak reverse voltage and the average forward current, a higher quality bridge diode would be better, I suppose.

For Handoko-san’s Model 7, I added high quality mica capacitors to run the switching noise to ground as much as possible, but it is difficult to hear the improvements.

You can also see (right) the Mallory tubular electrolytic condenser, 30μF/450VDC, connected in parallel with the oil-filled capacitor, a Blue Cactus 0.22μF/600VDC.

I felt intuitively that by increasing the capacitance of the main capacitor, that +B rectification would be better and needed.

Luckily, I have some stocks of this desirable sounding Mallory. It not only has an exceptionally low E.S.R. value throughout its entire range, but also it brings out the sound in an entirely satisfactory way.

I don’t hear any particular tonal character from it, but it has rich timbre, and a sound that is responsive,  bright, and with an immense sound stage, which is exactly the same first impression I had of it 37 years ago when I completed my Marantz Model 7 kit.

My next challenge is to produce a better sounding electrolytic capacitor, one that could surpass this Mallory, and I already have a prototype of the first sample from Yoneda-san at Nichicon. His engineering sense for technology and also his hearing, is extraordinary, so I have great expectations!

To be continued later!


Many thanks to Yazaki-san for sharing his life with the Marantz Model 7 with us!

There’s a lot to think about and absorb from what Yazaki-san has said in Part 2, and I’m in the process of digesting it all, while at the same time contemplating some adventures based on his recommendations.

I’m already looking forward to reading Part 3 of of Yazaki-san’s article My Adventure with My Old Marantz Model 7k, and as Yazaki-san likes to say, please wait for it!

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

 Posted by at 5:57 am
May 262017

A care package of Duelund DCA12GA tinned-copper tone wire arrived from Frederik today! Woo hoo!

I’ve really been looking forward to giving the new Duelund DCA12GA a listen after reading all of your positive comments about it!

A care package from Frederik containing Duelund DCA12GA tinned-copper has arrived at Jeff’s Place!


As a reminder from the breaking news post announcing the new DCA12GA, it uses 65 strands of 0.25mm tinned-copper wires versus the 26 strands of 0.25mm tinned-copper strands used in the DCA16GA, and it uses the exact same oil-soaked and baked cotton dielectric.

Left to right: DCA20GA, DCA16GA, and DCA12GA.

In the photo above you can see the  DCA20GA, DCA16GA, and DCA12GA, left to right. While you can tell that the DCA12GA is much bigger than the DCA16GA, it’s hard to appreciate how much bigger it is until you hold it in your hand – it is one substantial wire!

Duelund DCA12GA awaiting some test runs!

The new DCA12GA is one heavy duty wire!

Parts ConneXion will have exclusive distribution of the DCA12GA for the first few months after its release.

Parts ConneXion is offering the DCA12GA at a special introductory pricing of $16.99/meter, which after the exclusivity period will go to  $19.50/meter. The MSRP Retail List Price of the DCA12GA is $22.95/meter.

I’ll be reporting back on my initial listening impressions in the near future, with more detailed impressions over the coming weeks, so stay tuned!


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

 Posted by at 3:32 pm
May 212017

As most of you know, I’ve been a long-time fan of the Leben CS600 integrated amplifier, for it’s rugged & reliable build quality, it’s superb appearance, its great sound & musicality, and its flexibility in accommodating a lot of different power output types for tube swapping entertainment.

Sophia Electric EL34-ST tubes peeking out over the top of the Leben CS-600.

The only nit I have to pick with the Leben CS600 is the lid, which will only accommodate the shortest output tubes, otherwise your CS600 has to go topless, like the photo above with the Sophia Electric EL34 Aqua tubes shows.

I have long hoped that Leben would offer a special cut-away or raised lid kit that would allow the listener to run taller tubes, while still be able to use the lid. It’s never happened.

However, Robbie has come up with a great solution which I hope to try for myself shortly, and Robbie has been so good as to share it with us – thank you Robbie!


Hi Jeff,

Firstly it’s so refreshing to see how you interact with your readers.  Not only do you give great insight into musical systems and very interesting and cost effective mods but actually take the time to read and reply to us punters, great work!

Your question on where to get the risers has actually led me to an even better, less fiddly solution.  Still using brass motherboard risers/standoffs but I found that instead of the female/female ones I had on hand you can also get male/female risers than screw into the case rim from the top, really could not be easier now.

Due to the differing height requirements people may have – KT88 vs KT120 – I think the linked ebay auction would be a great start as it includes a variety of heights. And at approx. $5 with free shipping it aint gonna break the bank.

(Note: The auction Robbie referenced is no longer available at the link he provided for me, but I included another link above to another listing for a “120Pcs M3 Male Female Hex Brass Spacer Standoffs PCB Board Screws Nut Assortment” on eBay that sounds equivalent to me, and I ordered one for myself – Jeff)

For the treasures I use a 10mm height which clears the glass easily.  Below is the new male/female riser.

As a safety measure I’d advise trying to screw in one of the Leben torx screws into the riser first.  It should go in with no resistance.

Any resistance indicates the threads may be incompatible.

Then simply affix as may risers as you want to the top plate mounting holes on the chassis.  I found 4 to be ok, but the linked auction has 10x of each height so the rim could be fully populated.

Close up with lid (didn’t fully tighten that screw by the looks, shoddy!)

And a wider shot, the foreground risers is shadowed but is there.

In the flesh it looks less noticeable than the photos and provides full protection with taller tubes.

Interested to know what you think!




Many thanks to you, Robbie, for your kind words, and sharing your Leben CS600 lid tip with us – it is greatly appreciated!

As soon as I get my risers I’ll give it a try and report back.

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

 Posted by at 8:46 am
May 192017

It was a long week of getting caught up at home and on the day job, and getting over jet lag! I love traveling but playing catchup is rough!

But now it’s weekend-eve, and it’s time for a little music listening! Woo-hoo!

First up was the new mono Buddy Holly reissue from Analogue Productions, remastered by Kevin Gray at Cohearent Audio from the original analog master tapes, and pressed at Quality Record Pressings.

I’ve always enjoyed Buddy’s first solo album and considered it one of the treasures of early rock & roll, so I couldn’t resist buying a copy when I saw it had become available on the Analogue Productions reissue label.

The album is beautifully done all the way around, terrific music, careful remastering, a 200 gram record, and a nice tip-on style gatefold jacket.

I’m probably not as enthusiastic about this reissue as some of the other reviews I’ve seen of it, but still, it’s a great album, and if you love early rock & roll you will not want to miss it!

I haven’t heard the original 1958 release on Coral, but you can pick up an original in decent condition on Discogs for about the same price, which I also find quite tempting.

I suspect whichever one you go for you’re going to love it, this is great music!

Another album that I’ve had a life-long love affair with is The Sound of Jazzwhich was released in both mono and stereo by Columbia in 1958, and the stereo version was just reissued by Chad on Analogue Productions.

The Sound of Jazz from Analogue Productions was mastered by Ryan K. Smith at Sterling Sound from the original 3-track tapes, pressed at Quality Record Pressings as a 200 gram LP, and packaged in a very nice tip-on jacket.

This is a phenomenal record, and if you love jazz you will not want to miss it, as Analogue Productions really hit a home run on this one, and everything about it is first class, and as I’m listening to it right now it is completely blowing me away!

Analogue Productions did a nice job on their Buddy Holly reissue, but The Sound of Jazz is at another level, just out of this world! Man, I love this record! Way recommended!

Just for kicks, I also ordered the original mono version of this record from Discogs, so I’ll report back and let you know how it compares to the Analogue Productions stereo version. Stay tuned!

Masterpieces by Ellington at 45 RPM.

Then there’s the third record for the weekend, the Analogue Productions 45 RPM mono version of Masterpieces by Ellington (above).

The mono 33 1/3 Masterpieces by Ellington blew me away!

The 33 1/3 mono version that Analogue Productions did of Masterpieces by Ellington totally blew me away when I heard it (above), so I couldn’t resist the premium 45 RPM version that was just released!

The 45 RPM Masterpieces by Ellington was also remastered by Ryan Smith at Sterling Sound, from the original analog tapes, cut at 45 RPM, and pressed on two 200 gram LP’s at Quality Record Pressings, and features a gatefold tip-on style jacket.

Masterpieces by Ellington on 45 RPM – to die for!

It took me all of a millisecond to be completely blown away by the 45RPM version of Masterpieces by Ellington, this is a super record set!

Masterpieces by Ellington on 45 RPM!

Masterpieces by Ellington on 45 RPM is a masterpiece in itself, don’t miss this one! Kudos to Chad & Ryan on this one, man, you guys nailed it!

Ok, time for a little more listening!

Thanks for stopping by, and from my home to yours, may the tone be with you and the music make you happy!

 Posted by at 6:48 pm
May 182017

As I alluded to in my earlier blog post, while I was traveling in Eastern Europe over the last few weeks, I received a message from Mr. Shirokazu Yazaki in Tokyo, Japan, about an article he has been working on for some time now for the readers of Jeff’s Place, and one that I was very excited to read and tell you about!

Yazaki-san (center) with friends in Tokyo.

Those of you who are regular readers of Jeff’s Place are already very familiar with the beloved Yazaki-san, but for those of you who are new to Jeff’s Place – there’s a lot of you lately – I would like like to do a proper introduction for you to Mr. Shirokazu Yazaki, and the very important influence he has had on me personally, and I believe, the course of hobbyist audio around the world, over the last few years.

Mr. Shirokazu Yazaki first came to my attention during my review of the SPEC RSA-M3 EX Real Sound Amplifier that I wrote about for Positive Feedback, back in early 2015, in Issue 78.

SPEC RSA-M3 EX Real Sound Amplifier.

In writing that article about the very nice SPEC RSA-M3 EX Real Sound Amplifier, I became so enchanted by Yazaki-san’s life & story, and his approach to audio design, that I wanted to share what I was learning from him with all of you, as I found what he had to say was so interesting & illuminating.

With Yazaki-san and his ideas about Real Sound and how to achieve it, I felt like I was witnessing something new, as well as a revival of something forgotten, which together made for something important under the audio sun.

Yazaki-san’s life’s story, his considerable insights into the relationship of music-making to audio design, made such a big impression on me and the way I view the world of music reproduction in home audio, that it sparked a series of exciting audio adventures that are still going strong after two years now, and with no end in sight!

Real Sound modified vintage McIntosh MC30 monaural amplifiers with Western Electric WE16GA as speaker cables.

I described the beginning of my audio adventures with Yazaki-san in Adventures in Real Sound with Mr. Shirokazu Yazaki, in Issue 81 of Positive Feedback, where I shared with you Yazaki-san’s concept of Real Sound, and how we pursued Real Sound as we engaged in capacitor & resistor adventures with my vintage McIntosh MC30 monaural amplifiers.

What I learned from Yazaki-san about voicing equipment with capacitors, resistors, and tinned-copper wire for Real Sound was revelatory for me!

Notably, in that article I also discussed Yazaki-san’s recommendation of the use of vintage Western Electric WE16GA wire used as speaker cables, and the use of the recording studio classic Belden 8402 microphone cable as interconnects, and how the combination of the musicality & sonics of their Real Sound tinned-copper conductors impressed me so much that I rewired my whole audio system them.

Spool of vintage Western Electric WE16GA tinned-copper wire on its way to becoming speaker cables.

It would turn out that Yazaki-san’s recommendation of the Western Electric & Belden 8402 brought to light the forgotten musicality of the use of tinned-copper conductors in audio, and his recommendation ended up being an audio ‘shot that was heard around the world’.

As a result, as listeners around the world began to discover the musical magic of tinned-copper conductors for themselves, a tidal wave of interest developed around their ‘vintage tone’ that has not abated to this day, and it fundamentally changed the kind of musical & sonic expectations that many of us have when it comes to audio wiring & cabling. As a bonus, these tinned-copper cables were very inexpensive, so many of us could afford to experience & experiment with them!

But I digress a little in my excitement, so let me get back to my introduction of Yazaki-san, with a couple of illustrative excerpts from the introduction of the SPEC RSA-M3 EX Real Sound Amplifier article, to introduce you to Yazaki-san the man, and set the stage for the article he has written for us:

“I have found the story of Mr. Shirokazu Yazaki’s audio journey during our conversations to be quite fascinating, and I’m hoping I can relay that sense of intrigue to you, and why I think his story is important.

First of all, Mr. Shirokazu Yazaki has been a successful professional audio designer in Japan for over 40 years, and has been involved in the design of many fine audio components from some of the foremost Japanese electronics companies during that time. Yazaki-san fondly reminisces about a few component design high points he was involved with, like the TEAC A-7300 semi-professional open-reel tape recorder while he was at TEAC, or the Pioneer CT-95 / T-1100S cassette recorder as a design team leader & manager at Pioneer in their cassette recorder engineering department, or the Pioneer DV-AX10 universal disc player as the general manager for the Pioneer DVD engineering department.

Those of you with a detailed historical knowledge of audio will remember the highly regarded TEAC A-7300 reel-to-reel; the Pioneer CT-95 / T-1100S cassette recorder, which was considered superior to even the legendary Nakamichi Dragon; and the Pioneer DV-AX10, which was the world’s first true universal disc player capable of playing CD, SACD, DVD and DVD-A with both high audio & video fidelity.

Towards the end of his career at Pioneer, Mr. Shirokazu Yazaki was put in charge of the Pioneer research & development center, where he first came into contact with a prototype class-D switching amplifier in 2006.

Ok let’s stop right here for a moment. Now we are going to journey back in time 40 years or so to 1971 when Mr. Shirokazu Yazaki first started his professional audio design career at TEAC, a young man fresh out of the university with a mechanical engineering degree.

There were events occurring during that time that would mark it as one of the defining periods of audio history, which would send ripples of inspiration through time to the future to spark an audio revolution that changed the way that many of us today think about what’s possible in high-performance audio.

Over the years as an audio writer, it has been a great pleasure for me to interview a number of eyewitnesses who were involved from the beginning of that important period, like Mr. Shirokazu Yazaki, and to tell the story of how events unfolded, and how those events would come to shape the future of enthusiast audio, including my own enjoyment of music today.

While Japanese audio enthusiasts were familiar with the excellent American vacuum tubes from Western Electric, RCA, GE, etc., they didn’t have a lot of access to European and British vacuum tubes until towards the end of 1960s, when a most important event occurred with French audio connoisseur Jean Hiraga (of L’Audiophile fame) starting to import European & UK vacuum tubes to Kobe, Japan.

Magazines like MJ and Radio Engineering were publishing do-it-yourself (DIY) articles about building vacuum tube amplifiers, including some using those ‘new’ European & UK vacuum tubes from Jean Hiraga, which were embraced by the creative ‘underground’ audio movement in Japan. There were a lot of really interesting designs taking shape around the vacuum tubes that were available from America, Europe, and the UK, and in particular around the ascension of directly heated single-ended-triode power (SET) amplifiers that were intended for use with high-sensitivity horn loudspeakers.

The Tokyo Audio Fair of 1971 featured a number of those vacuum tube amplifier designs, and notably the combination of DH-SET amplifiers driving high-sensitivity Altec A-5 loudspeakers, which wowed show goers with their superlative music-making ability, including our young Mr. Shirokazu Yazaki who had just started his career at TEAC.

Now the young Mr. Shirokazu Yazaki who went to work at TEAC was also an audio enthusiast & music lover who particularly enjoyed listening to jazz, so in 1971 when Yazaki-san went to the Tokyo Audio Fair he was impressed by the intense musical satisfaction that could be realized by listening to music with DH-SET amplifiers powering high-sensitivity Altec horn loudspeakers.

Excited by the possibilities of that 1971 Tokyo Audio Fair, Mr. Shirokazu Yazaki embarked upon what would become a life-long journey of assembling & refining his personal high-fidelity music system, first by constructing his own DH-SET amplifier, then by building and customizing a Marantz 7 kit preamplifier, and over time developing his Altec & Onken-based horn loudspeakers.

DA30 SET monaural amplifier.

In 1972 Yazaki-san began building his own SET amplifier after reading an article in the June issue of MJ magazine by a Mr. Anzai about building a simple GEC DA30 SET amplifier. Yazaki-san completed that first SET amplifier in early 1973, using the American Western Electric 310A as the driver, a Western Electric 274B as a rectifier, and the English GEC DA30 as outputs (the DA30 is less well known in the West, than say the 300B is, but it is held in extremely high regard by aficionados within the Japanese DH-SET scene, but they are rare and difficult to come by these days).

Mr. Shirokazu Yazaki told me that he has continuously improved his DA30 DH-SET stereo amplifier over the years, and the combination of Western Electric 310A driver, Western Electric 274B rectifier, and GEC DA30 outputs provides the most beautiful tonality he has every heard from an amplifier. Even though they were both capable of putting out 8-9 watts, Yazaki-san told me he selected the GEC DA30 over the Western Electric 300B for his amplifier because it had superior high-frequency response. He also went on to say that the oldest version of the Western Electric 310A, the ‘mesh shield’ that was produced in the 1930s & 1940s, was critical to getting the best sound. He thought that later versions of the WE 310As sounded rougher & less natural compared to the smooth & natural sounding original ‘mesh shield’ version. Yazaki-san also told me that the 1940s ‘engraved’ version of the Western Electric 274B rectifier expressed tonal colors better than all the other rectifiers he had experimented with. Compared to the ‘engraved’ version of the 1940s WE 274B rectifier, he found the Telefunken GZ34, Philips original GZ34, Mullard GZ37, GZ37 big bottle, RCA5R4GY, Western Electric 422A, etc., while excellent rectifiers, all bleached the tonal color to some extent.

The Western Electric 310A driver, Western Electric 274B rectifier, and the GEC DA30 outputs resulted in a rich midrange, beautiful tone, and a powerful upper bass that combined to give exceptional musicality.

Yazaki-san’s vintage Marantz Model 7k preamplifier.

In 1979 when Marantz released the Marantz 7 in kit form, Yazaki-san bought the kit and built it up with better parts. Yazaki-san said he learned a lot about getting good tone modifying his Marantz 7 kit with different components, and he has made continuous improvements to it to the present day.

Mr. Shirokazu Yazaki described to me the sound of the audio system he built as being transparent, beautiful, rich, and dynamic, but most importantly it possessed “real stereoscopic sound full of musicality.””

Ok, that serves as a good point to transition to the article Yazaki-san has written for us, My Adventure with My Old Marantz Model 7k, of which you can read the first installment of below.


My Adventure with My Old Marantz Model 7k

Dedicated to Saul B Marantz and Sidney Smith for their true masterpiece!


Shirokazu Yazaki

I have a story to tell about my personal days with the Marantz Model 7k, that I have enjoyed for nearly 40 years now, and I would like to share it with the readers of Jeff’s Place.

Every time when I recall my audio-life with my Model 7k, I get drawn into a state of retrospection. The Marantz Model 7k preamplifier had just been released as a 25th anniversary project of Marantz at the “Japan Audio Show” in the Autumn of 1978.

When I first heard the news of release of this preamplifier I was working at Pioneer as a professional engineer, where I specialized in designing tape transport mechanisms. Towards the end of 1978 I succeeded in developing a really high-performance dual-capstan cassette tape transport loaded with the latest Quartz Lock Direct-Drive capstan motor, which was a core-less reel motor featuring an Alnico magnet, made by Maxon/Swiss. The wow & flutter performance of this mechanism recorded easily the outstanding level of under 0.03 WTD-RMS. A gigantic cassette tape recorder, the CT-A1, featured this transport mechanism, and it was an exciting time for me when it was released in early 1979.

1979 turned into my most memorable year, when in May of 1979 I married Yumi, and I felt like my true life had just begun.

Those years must be the golden days for the audio hobby and industry in Japan, and I was excited to find the display at the show that showed all of the parts used in Marantz Model 7k. The Marantz Model 7k in kit form was a very appealing product for me, as you might imagine.

By that time in Japan, the Marantz Model 7 had an established reputation as a high quality vintage preamplifier, known not only for the outstanding sound quality of its unique three-stage phono equalizer circuit design, but also for the beautiful and well-designed appearance of its front panel.

At that time I had only imagined what the Marantz Model 7 might sound like, and I was so intrigued by its simple and beautiful front panel design, which had neither too much, nor too little, in the way of features, and I felt like there was some kind of advanced intelligence that was behind its design and appearance.

In those days, I was an eager reader of MJ magazine, and at last I found a valuable article of how to build up the Model 7k written by Morikawa-san, in the March 1979 issue.

Morikawa-san was not only a main writer for MJ at that time, but also the senior writer about tube amplifiers. Actually, he introduced me to the world of the high quality parts made in USA through his articles.

I don’t remember how many times I had read the article and got detailed valuable information about the differences between the original vintage Marantz Model 7 and the 25th Anniversary Marantz Model 7k, and the know-how of building up the kit.

Morikawa-san finished up his article with the impressive words, “After the comparison hearing test between original Marantz Model 7 and the 25th Anniversary Marantz Model 7k, while changing a lot of parts included in the kit to get best performance, I reached the conclusion that it takes a long time for aging of the component parts to get the full performance they are capable of. The sound of the vintage Model 7 has quite simply convincing sound, and the sound leads us to the sensation of another world of musicality, but the sound is different from the brand-new Model 7k. And so it would be meaningless to compare the sound of the newborn Model 7k and the vintage Model 7, I believe. And it would be needed for you to wait patiently for numerous years after building up the Model 7k with the carefully selected parts, before you find for yourself that your 7k might reach the incredible level of the vintage Model 7 at some day in the future.”

I was so encouraged by his words, and I made up my mind to get the Model 7k. I bought the kit on the 8th of December in 1979 at a shop in Akihabara, and now after 37 years have passed, I can fully agree with and understand well the meaning of what Morikawa-san expressed about the optimum selection & aging of components over a long time.

Well, I gleaned a lot of insight from Morikawa-san’s MJ article and its photos on how to select the parts for the modification of my Model 7k, and actually I changed the main VR, resistors, and capacitors from the parts attached to the kit to the more desired ones for me. Fortunately enough, on January 27, 1980, I completed the assembly of my Model 7k, and it worked very well.

I remember this time very well because Yumi had to stay in the hospital from early January until March 1980 because of the risk of losing our baby while she was pregnant, but blessedly, our daughter, Atsuko, saw the sun safely in that October. In such circumstances things are etched into your memory, and it was at that same time that my audio life with Model 7k had just started.

When I first listened to the sound of my Marantz Model 7k that I had just finished assembling, I was very impressed by the sound which was full of musicality, especially the comfortable mid-low range with such rich atmosphere. At that moment, I clearly understood that the electrolytic capacitor by Mallory in power supply might mainly bring out this attractive low range.

This was the start of my “Capacitor Adventure “. Back in those days, the capacitors made in Japan had never reached the level of sound quality of those capacitors made in the USA, except for the mica capacitors, and also same thing was true for the tubular types of signal capacitors.

In the middle of the 1990’s I upgraded my Model 7k with tubular caps, such as the Black Beauty and TRW (Good-All). I felt the sound of my Model 7k at that time very stable and had rich mid-low range by these tubular capacitors, covered with thermosetting resin.

I actually experienced the true power of my Model 7k when Banno-san’s team, who is now working with me and Spec Corporation, had designed and developed the first universal player, the Pioneer DV-AX10, in my engineering department in 1999.

I used my Model 7k in a well-equipped listening room for tuning up the sound of AX10 for more than half year, where fortunately we could compare it to many types of high-end semiconductor preamplifiers of famous brands, both domestic and overseas, but none of these preamplifiers compared to my Model 7k for its musicality. We couldn’t hardly believe it, but only my Model 7k could fully show what the AX10 was capable of. Of course, my modifications to the Model 7k have continued after that, and up to the end of this March.

It was lucky for me to have bought my Model 7k in kit form, because it allowed me to easily change any of the parts for the modification without any constraint. If I had managed to succeed in getting the vintage Model 7, it would have been much more difficult to easily to use or change to new parts for the modifications.

Yes, I could understand well the sentiments of many vintage Model 7 lovers who place importance on having an absolutely original Model 7 because of its fame and virtues as a real treasure, but I believe in the tremendous potential for improving the “Sound-Quality” of the Model 7 due to my many experiences over a long period of time.

When I say “Sound-Quality“ it is a little hard to explain, as what I mean by sound quality depends on my personal hearing sense or the sense for the music itself. In a word, it would be “Real-Sound” for me, but the one thing I can say is that when the sound quality reaches a certain level, we can fully enjoy any kind of music source from all ages and countries, for example, from 1950’s jazz to cutting-edge high-resolution recordings of classic music, and for example, I can hear and enjoy more intimately the attractive smoky voice of Julie London with my Model 7k just now while listening, after performing numerous modifications.

I would like to tell you one more thing about Model 7’s virtue. Marantz said that the phono EQ circuit design was very unique, and the front panel featured sophisticated asymmetrical design, and yes, I fully agree, but I would like to point out the excellence of the structure and the design of the chassis.

The front, top, bottom, two-side and rear plane were made of only thin aluminum plates, divided into four components, instead of using usual rolled steel plate.

This all aluminum chassis provides the necessary strength for the chassis of the preamplifier, but is not so rigid as to be detrimental to musicality as with some modern audio preamplifier designs.

I believe the chassis design of Model 7 is just right from a strength and rigidity standpoint, because I have experienced that too robust a chassis and too rigid of a chassis material for audio gear often leads to an uninviting or ‘cardboardy’ sound. Some inner dissipation is needed in the chassis’ mechanical structure, and also some material for the natural damping of minute vibration of the electric parts is needed for getting a comfortable sound, I think.

The aluminum chassis is also able to allow electromagnetic waves to be transmitted out. If the radiation waves emitted in the circuit cannot get out it is a very negative factor, I think, or if the transformer and the parts cannot dissipate minute vibration into the chassis. I suppose all these factors is what gives such a light and airy sound from the Model 7.

I know I’m repeating myself, but I have long respected the geniuses who created such a marvelous and an outstanding preamplifier in the Marantz Model 7, Saul B Marantz and Sidney Smith.

I strongly believe that my dedication to ongoing modifications throughout the last 37 years are a testament to the immeasurable value of Model 7’s design.

And so I hope, that by sharing my thoughts and modifications with the readers of Jeff’s Place, that I could offer some suggestions or help for Model 7 lovers who want to get out the full potential of this true masterpiece.

Yazaki-san’s vintage Marantz 7k preamplifier.


Ok, that’s it for now for the first installment of Yazaki-san’s article about his life with the Marantz Model 7k preamplifier.

I’d like to offer a huge “Thank you!” to Yazaki-san for sharing with us about his life with the Marantz Model 7k, and his personal thoughts about its legendary performance, as well as his approach and methods for taking it to the next level of performance in Real Sound!

In subsequent posts of Yazaki-san’s article, Yazaki-san will be discussing with us his method for implementing modifications, and will go into depth about how he strengthens the power supply, the addition of decoupling, upgrading the coupling capacitors, and upgrading resistors.

As Yazaki-san likes to say, “Please wait for it!”.

Stay tuned for more, and until then, may the tone be with you and the music make you happy!

 Posted by at 5:48 pm
May 152017

I just got back home from two weeks of travel with little to no internet & email access most of the time, so I’m way behind on addressing comments & writing blog posts, and I’m playing tag with jet lag.

I did get a chance to listen to a variety of live music performances of jazz, classical, folk, and opera (Madame Butterfly and Electra), while traveling, which was really nice.

There’s nothing like listening to live music for pure musical enjoyment, and as a reality check too, as there’s nothing that keeps you calibrated for hi-fi games like live music, so those concerts were a double treat!

I’ve actually lost track of how many concerts we attended during the last two weeks, as well as the almost daily musical experiences we had along the way, but it’s an awesome way to recharge one’s musical batteries!

If you haven’t heard from me yet on a comment you’ve made here at Jeff’s Place, it’s not because I forgot you, rather I’m just way behind, so I’ll be trying my best to get caught up over the next week or so.

The Sumile mounted to the Schick graphite headshell.

I also tried something new.

The Power Reference TripleC NCF AC power cord & the RPT-6 Absolute NCF Power Distributor with the RPT-4 Ultimate Power Distributor and Power Reference AC Power Cord.

Since I knew my ability to write would be severely limited, I used WordPress’s autopost feature while I was gone to post three new posts that I had written for you before I left.

Duelund DCA16GA tinned-copper conductors terminated with Duelund gold RCA’s.

I hope you enjoyed them!

I have news to tell you about a couple of exciting audio treats to come, so more about that in the near future!

Yazaki-san (center) with friends in Tokyo.

Important news! Yazaki-san turned 70 on April 25th, so please join me in wishing Yazaki-san a belated “Happy Birthday!”.


Happy Birthday, Yazaki-san!


I also have a guest article from Yazaki-san describing his life-long journey with the classic Marantz Model 7 preamplifier, which I’m really looking forward to sharing with you.

Yazaki-san’s vintage Marantz 7 preamplifier.

By the way, after Jeff’s Place got hacked, my email notifier for new posts quit working, and I was able just today to get it back up and running. Thanks to all for the feedback on it!

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

 Posted by at 2:16 am
May 132017

Which is better? The Duelund DCA16GA, Duelund DCA20GA, or the Duelund Silver/Silk interconnects?

Duelund DCA16GA tinned-copper interconnects terminated with Duelund gold RCA’s.

Duelund DCA20GA interconnects.

The conclusion that I’ve come to is that they all are better, depending upon the application I’m using them for.

Duelund DCA16GA interconnects between my vintage Mac’s.

For example, I had been using a set of nude Duelund DCA16GA interconnects to connect my vintage McIntosh MX110Z tuner-preamplifier and vintage McIntosh MC30 monaural amplifiers, and was liking the results.

I then tried the Duelund 1.0 silver/silk interconnects terminated with Duelund Rhodium RCA’s that Chris at Parts ConneXion built up for me, but they sounded too laid back and blah between my vintage Mac’s, so out they came and the Duelund DCA16GA tinned-copper interconnects went back into the system.

Duelund DCA20GA interconnects.

Then the Duelund DCA20GA tinned-copper tone-wire arrived, and I built a pair of interconnects so I could compare them to the DCA16GA interconnects between my Mac’s.

Duelund DCA20GA interconnects on the MC30’s.

When I connected my MX110Z & MC30’s with the Duelund DCA20GA interconnects, I really liked what I was hearing.

The sound was even more balanced top-to-bottom, smooth, articulate, nuanced, and very naturally ‘real’ sounding, and I was immediately smitten with the results! Wow!

A completed pair of shielded Duelund DCA20GA interconnects!

I was on a roll, so I decided I’d build up a pair of shielded DCA20GA interconnects to try between the Auditorium 23 SUT and MX110Z, for use with the Sumile phono cartridge that’s in for review.

Shielded DCA20GA tinned-copper tone-wire interconnects.

It turns out that the shielded DCA20GA interconnects didn’t perform nearly as well with the A23 SUT to MX110Z connection as I’d hoped, and they certainly weren’t as brilliantly musical as the nude DCA20GA’s were between the MX110Z and MC30’s.

Duelund shielded silver/silk interconnects with Duelund Rhodium-plated connectors.

Then I tried the shielded Duelund 1.0 silver/silk interconnects terminated with Duelund Rhodium RCA’s that Chris at Parts ConneXion built up for me, to connect the A23 SUT and MX110Z, and it was a match made in heaven for use with the Sumile phono cartridge!

The same sort of thing happened with the very nice Belden 8402 microphone cable interconnects that I was using between my Intact Audio SUT’s that I use with my Ortofon SPU Classic GM MkII.

Duelund DCA16GA shielded IC’s for phono on my Intact Audio SUT.

When I tried the shielded DCA16GA interconnects that Chris at Parts ConneXion made up for me, they were incredibly musical & engaging on the Intact Audio SUT’s, with great presence and vivid tone colors that really made the music come alive, and ended up displacing the Belden 8402 interconnects I had been using in that position.

Next I’ll try the shielded DCA20GA interconnects I built on the Intact Audio SUT’s and compare them to the shielded DCA16GA interconnects that Chris built. I’ll report back when I get that done.

Here’s the moral of this story:

The Duelund DCA16GA & DCA20GA tinned-copper cables, and the Duelund 1.0 silver/silk cables provide a useful range of voicing attributes for various interconnect applications, and have allowed me to dial in the musicality & sound the way I like it, by choosing the most musically satisfying one for a particular application.

The beauty of this sort of approach is that you can build up a set of each of these interconnects, have an interconnect stable to experiment with, and still be in them for less cost than it would be for one set of hoity-toity interconnects from one of the more typical wire mavens.

Besides being a great way to fine tune a system’s voicing, it’s a heck of a lot of fun for not much money!


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

 Posted by at 6:41 am
May 062017

I’m working on my next feature length article for Positive Feedback, which will be about the Acoustic Revive Power Reference TripleC NCF AC power cord, the RPT-6 Absolute NCF Power Distributor, and the RAS-14 TripleC NCF Power Conditioner.

The Acoustic Revive RPT-6 Absolute NCF power distributor.

The Acoustic Revive RAS-14 TripleC NCF Power Conditioner.

2-meter Acoustic Revive Power Reference TripleC NCF AC power cord.

When I’m all done with this article for Positive Feedback, it will be my fourteenth feature length article about Acoustic Revive products!

  • Chapter 1 – The Acoustic Revive RR-77 Schumann Ultra Low-Frequency Pulse Generator – 6Moons, February 2008.
  • Chapter 2 – The Acoustic Revive RIQ-5010 / RIQ-5010W Quartz Insulators; QR-8 Quartz Resonators – 6Moons, March 2008.
  • Chapter 3 – The Acoustic Revive RCC-24 Ground Conditioner; SIP-8F RCA Input Shorting Plugs; QR-8 Quartz Resonators – 6Moons, May 2008.
  • Chapter 4 – The Acoustic Revive RPT-2 & RPT-4 Ultimate Power Distributors, Power Reference  AC Power Cords – PFO Issue 39.
  • Chapter 5 – The Acoustic Revive REM-8 EMF Canceler – PFO Issue 40.
  • Chapter 6 – The Acoustic Revive RWL-3 Acoustic Conditioner, CB-1DB Receptacle Base Plate, the CFRP-1F Carbon Fiber Outlet Plate, and the CS-F2 Outlet Stabilizer – PFO Issue 42.
  • Chapter 6a – The Acoustic Revive RIO-5II Negative Ion Generator & RD-3 Disc Demagnetizer – PFO Issue 45.
  • Chapter 7 – The Acoustic Revive Custom Series Loudspeaker Stands, the RST-38 & TB-38 Quartz Under-Boards, and the RAF-48 Air Floating Board – PFO Issue 47.
  • Chapter 8 – The Acoustic Revive Single Core Speaker Cables, Single Core RCA Interconnects, and the RCI-3 Cable Insulators – PFO Issue 49.
  • Chapter 9 – The Acoustic Revive RAS-14 AC Power Conditioner and the USB-1.0SP USB Interconnect – Issue 55 (May-June 2011).
  • Chapter 10 – The Acoustic Revive RR-777 Schumann Pulse Generator, the RL-30 Mark III Analogue Disc Demagnetizer, the CB-1DB receptacle base plate, CFRP-1F carbon fiber outlet plate, and the Acoustic Revive modified Oyaide R-1 receptacle – Issue 68 (July-August 2013).
  • Chapter 11 – The Acoustic Revive RR-888 Ultra Low-Frequency Pulse Generator, Single Core PC-TripleC, PCOCC-A, and Line-1.0RS RCA Interconnects, Oyaide R-0 AC outlet, and cruzeFIRST Audio Maestro AC outlet – Issue 76 (November-December 2014).
  • Chapter 12 – Acoustic Revive RPC-1 Power Supply Conditioner – Issue 89 2017.

That’s a lot of writing, and it’s more than I’ve written about any other audio company, simply because Mr. Ken Ishiguro keeps raising the bar on what can be done with audio products!

Ken-san’s audio devices have always done just what he said they’d do in my hi-fi – improve it – so I keep writing about Acoustic Revive products as Ken-san comes up with new ideas for improving system performance!


If you look closely at the photos that accompany my blog posts, and feature articles for Positive Feedback, you’ll see Acoustic Revive products everywhere in my systems, a subset of which are shown in the photos above.

That’s because the Acoustic Revive products have stood the test of time and have elevated the performance of my hi-fi systems over the long term!

A lot of things come and go in your hi-fi systems when you’re an audio reviewer. Equipment gets replaced by something new that is doing nicer things musically or sonically than something you have.

One of the big exceptions to that rule in my systems are Mr. Ken’s Acoustic Revive products, as they have had staying power in my systems by providing long term value through consistent performance improvements!

My original Acoustic Revive RR-77 from nine years ago I still use every day – that’s value!

Let’s take the example of the original Acoustic Revive RR-77 Schumann wave generator that I reviewed nine years ago (above).

Even after nine years, and three model evolutions later (the RR-777, and now the RR-888),  I still use the RR-77, RR-777, and the RR-888 in my systems.

For just the right amount of Schumann conditioning in my larger main music listening room, I use the original RR-77 in combination with the latest RR-888, which makes every listening session more enjoyable!

The evolution of the Acoustic Revive RR: The RR-77, RR-777, and RR-888, left to right.

In the smaller room where my audio-visual system lives, I use a single RR-777 Schumann generator for just the right amount of conditioning effect.

The RR series of Acoustic Revive Schumann generators have stood the test of time here at Jeff’s Place, and I still find them to be the most easily recommendable audio accessory there is. If you haven’t yet experienced what an RR can do for your music listening, you’re in for a treat!


Right now I’ve got the Power Reference TripleC NCF AC power cord and the RPT-6 Absolute NCF Power Distributor providing AC to, and getting some run-in time, in my main music listening system, and I thought I’d offer some initial listening impressions.

In Part 2 of this post I’ll offer some impressions of using the RAS-14 TripleC NCF Power Conditioner in my Altec A5 Voice of the Theatre based audio-visual system.

I use an RPT-2 Ultimate Power Distributor in my ‘Stokowski’ Altec A7 Voice of the Theatre music system.

I’ve been a long time user of the RPT-2 Ultimate Power Distributor (above) and the RPT-4 Ultimate Power Distributor (below).

The RPT-4 Ultimate Power Distributor I use in my Tannoy Westminster Royal SE based system.

First let me comment on the performance of the Power Reference TripleC NCF AC power cord and the RPT-6 Absolute NCF Power Distributor as a whole, then in future posts I’ll elaborate more on them as individual components as compared to my RPT-4 Ultimate Power Distributor and Power Reference AC Power Cords.

The Power Reference TripleC NCF AC power cord & the RPT-6 Absolute NCF Power Distributor with the RPT-4 Ultimate Power Distributor and Power Reference AC Power Cord.

I’ve been having a number of “Whoa!” moments lately, like with the Lefson Ultra resistors in my Altec A5 Voice of the Theatre crossovers, or the Murasakino Musique Analogue ‘Sumile’ MC phono cartridge, and now you can add to that “Whoa!” list the combination of the Acoustic Revive Power Reference TripleC NCF AC power cord & the RPT-6 Absolute NCF Power Distributor.

I had just finished shooting some photos of the Power Reference TripleC NCF AC power cord, the RPT-6 Absolute NCF Power Distributor, and the RAS-14 TripleC NCF Power Conditioner, for my Today’s Fresh Catch introductory post about them.

Acoustic Revive

They were cold out of the box with zero time on them, but just for the heck of it I thought I’d plug in all my gear into the RPT-6 Absolute NCF Power Distributor, then connect it with the Power Reference TripleC NCF AC power cord to my AC supply, and give it a brief listen.

Immediately I was impressed with the increased sense of ease and naturalness the RPT-6 Absolute NCF Power Distributor & Power Reference TripleC NCF AC power cord lent to the music.

It was as if the music just opened up and took a deep breath, then exhaled a relaxed, nuanced, musical experience. It was uncanny.

What struck me as interesting is that all of these, the Lefson Ultra resistors, the Sumile phono cartridge, and now the Acoustic Revive RPT-6 Absolute NCF Power Distributor & Power Reference TripleC NCF AC power cord, all had similar ‘trends’ in the way they improved the sonic & musical presentation.

What sonic & musical characteristics did these audio devices share?

They all share a common ability to display/enhance a huge, spacious, and artfully rendered sense of space and a deeply layered soundstage, which gives a very ‘live’ tactile sensation of music making & interaction among musicians, as well as a wealth of musically relevant nuance that is revealed in the timbral textures, tone color, dynamics, tempo, beat, rhythm, and harmonies.

Taken all together, my initial reaction was, “Whoa! That’s nice!”

As I get further into the review process I’ll provide some more detailed & varied comparisons of the Acoustic Revive RPT-6 Absolute NCF Power Distributor’s and Power Reference TripleC NCF AC power cord’s musical & sonic performance, but for now “Whoa!” is a pretty good summation!


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

 Posted by at 6:00 am
Apr 292017

The Murasakino Musique Analogue ‘Sumile’ MC phonograph cartridge makes me smile while I’m listening to music!

The Sumile MC phono cartridge. $8500 USD.

The Sumile reminds me of the exotic Lefson Ultra resistors from France, and like the Ultra’s, the Sumile is astonishingly transparent & resolving, while being rich, natural, and exceedingly musical at the same time – a very nice magic trick!

With the wirewound resistors in my crossovers it sounded like there was a sock stuffed in front of the compression driver compared to the incredibly transparent & musical Lefson Ultra resistors that allowed a whole new dimension of musical nuance, color, and richness flow through.

Going from my beloved Ortofon SPU Classic GM MkII stereo phono cartridge to the Sumile cartridge is akin to that example, in that the Sumile too has allowed a whole new dimension of musical nuance, color, and richness to flow through that was not apparent with my beloved SPU.

Tony Bennett at Carnegie Hall on the Analogue Productions label.

It’s amazing to hear how much more musically relevant information was lurking in my records than I realized with the Sumile cartridge tracing the grooves, and once heard, it is addicting.

Sonically the Sumile MC cartridge is superb, and on my Analog Productions remaster of Tony Bennett at Carnegie Hall the Sumile displayed a huge, spacious, and artfully rendered sense of space & deeply layered soundstage, making the images of each musician seem connected in interplay with each other, giving a very ‘live’ tactile sensation of music making & interaction among musicians, which is definitely fitting given Tony Bennett at Carnegie Hall was a live performance.

Murasakino Musique Analogue ‘Sumile’ MC phonograph cartridge.

While the sonics of the Sumile are superb, what really is impressing me about the Sumile is the wealth of musically relevant nuance that is revealed in the timbral textures, tone color, dynamics, tempo, beat, rhythm, and harmonies, which makes me feel intimately connected to, inspired by, and often awed by the music I am listening to.

The Duelund Shielded Soft Annealed Silver Foil Interconnect (shield grounded at source end) & Auditorium 23 SUT were magic with the Sumile!

As for setup, I decided that the nude DCA20GA interconnects that sounded so fantastic connecting my vintage McIntosh MX110Z tuner-preamplifier and my vintage McIntosh MC30 monaural amplifiers, weren’t bringing out the best of the Sumile in shielded form, when used for connecting my Auditorium 23 SUT to my MX110Z.

Instead I found the magic interconnect for use with the Sumile MC cartridge to be the Duelund 1.0 silver silk in oil wire terminated with Duelund Rhodium RCA’s that Chris at Parts ConneXion built up for me to try. The Duelund 1.0 silver silk in oil interconnects are a tonal match made in heaven for the Sumile!

The Sumile is imported/distributed by Tone Imports in North America. $8500 USD.

The Sumile is really hitting its stride in my system now, and it is absolutely gorgeous sounding, stunning both sonically & musically, and I find myself gravitating towards the Sumile every time I play a record, leaving my beloved Ortofon SPU Classic GM MkII stereo phono cartridge feeling a bit neglected of late.

Stay tuned, there will be much more to come on the enchanting Sumile MC phono cartridge from our friends at Murasakino Musique Analogue in Japan!

The Sumile MC phono cartridge is imported/distributed in North America by Jonathan Halpern at Tone Imports. $8500 USD.


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

 Posted by at 6:42 am
Apr 222017

It’s been far too long since I’ve done some tube rolling, so I was delighted to hear from Sue & Richard at Sophia Electric that they wanted me to give their new Sophia Electric EL34-ST vacuum tubes a review for Positive Feedback.

The new Sophia Electric EL34-ST vacuum tube.

I’m a real pushover for the ST bottle shape, I just love the way it looks, so the new Sophia Electric EL34-ST vacuum tubes really pushed my visual buttons!

Sophia Electric™ EL34-ST vacuum tube.

I thought it would be fun to try the new Sophia Electric EL34-ST vacuum tubes in my Leben CS-600 integrated amplifier, which has been with me longer than any other amplifier I own.

The Leben CS-600 is just a silly good amplifier, and is definately an old friend at this point!

Vintage McIntosh MC225 stereo amplifier with the A5’s.

I decided I wanted to try my Leben CS-600 with my Altec A5 Voice of the Theatre loudspeakers that I just hot-rodded with Lefson resistors in the crossovers, in my audio-visual system.

I have been using my A5’s with my vintage McIntosh MC225 stereo amplifier and Leben RS100U line stage (above), which is a really nicely matching combination of electronics with the A5’s.

Leben CS-600 with the Altec A5 Voice of the Theatre loudspeakers.

So I got busy and and unhooked the McIntosh MC225 stereo amplifier and Leben RS100U line stage,  set them aside, and then installed the Leben CS-600 integrated amplifier in my vintage Altec A5 Voice of the Theatre based AV system in their place (above).

I set the Leben CS-600 to its 16 Ohms setting for driving my 16 Ohm Altec A5’s.

Back panel of the Leben CS-600.

I’m using the Acoustic Revive Power Reference TripleC NCF AC power cord that’s in for review to provide AC to the Leben CS-600 (far left in the photo above).

The interconnects from my Philips TV to the Leben CS-600 are Belden 8402 microphone cable interconnects with the shield connected at both ends, Yazaki-san style (far right in the photo above).

Speaker cables are Duelund DCA16GA tinned-copper cables with no terminations, and are connected nude to the CS-600.

Oppo UDP-203 Ultra HD Blu-ray Disc Player

For a source I’m using the new Oppo UDP-203 Ultra HD Blu-ray Disc Player that I got a while back.

For interconnects from the Oppo to the Leben CS-600 I’m using Duelund DCA16GA tinned-copper cables terminated with Gold Duelund RCA’s that Chris at Parts ConneXion made for me to try.

By the way, the more I use the Duelund RCA’s the more I’m liking everything about them, they’re very nicely done and still work well with the narrow spacing on vintage gear, which is a requirement with my vintage tastes!

Duelund DCA16GA tinned-copper conductors terminated with Duelund gold RCA’s.

For connecting the Oppo to AC I’m using the superb Sablon Audio Quantum Gran Corona, which really is a sweet match to the Oppo!

Sablon Audio Quantum Gran Corona AC power cord.

Now a little more about the Leben CS-600. I fell in love with the Leben CS-600 integrated amplifier over ten years ago now when I wrote an article about it for 6Moons.

I ended up buying the review unit (the ultimate recommendation) and have been using it nearly every day in my AV system, where it has been reliably been an ongoing delight.

When the Altec A5 Voice of the Theatre loudspeakers displaced my Harbeth Super HL5’s from my AV room, the Leben CS-600 & Harbeth’s became my the system in my master bedroom.

Now the Leben CS-600 is back in my AV room, with the Altec A5’s, so I can try it with the new Sophia Electric EL34-ST vacuum tubes.

You can use a bunch of different tubes in the Leben CS-600 because of its adjustable cathode resistor and plate voltage settings, but primarily it is intended to be used with 6L6GC’s or EL34 tubes.

For those who are into tube rolling, I’ve posted a settings table for the different tubes you can use in the CS-600 here.

The Leben CS-600 integrated amplifier.

In addition to it’s gorgeous exterior, the Leben CS-600 is able to hold its own against pretty much anything out there.

Jonathan Halpern (Tone Imports) has had huge success winning ‘best sound of show’ praise (1, 2) with his Leben CS-600 at a number of hi-fi shows, impressing such hardened audio writers as Stephen Mejias, John Atkinson, Robert Deutsch, John Marks, and Art Dudley, for example, while shaming much larger & more expensive systems with his David versus Goliath system approach.

The CS-600 with the Sophia Electric EL34-ST vacuum tubes patiently awaiting their turn in the CS-600.

What kind of vacuum tubes was Jonathan using in his Leben CS-600 that garnered such impressive praise? If you guessed it was EL34’s you’re exactly right, and that’s what piqued my interest in giving the new Sophia Electric EL34-ST vacuum tubes a go in the CS-600.

A quad of Sophie Electric EL34-ST vacuum tubes for the Leben CS-600 integrated amplifier.

I played the CS-600 with the 5881 tubes I’ve been using in it for a couple of albums, to get a feel for its performance with my Altec A5 Voice of the Theatre loudspeakers, before switching to the Sophia Electric EL34-ST vacuum tubes.

Oh, by the way, the tube complement in my CS-600 is as follows:

  • Four National Electronics 5881 power tubes.
  • A NOS General Electric 6Cj3/6DW4B ‘dumper tube’ (allows for a gradually increasing supply of high voltage (B-Voltage) to the output tubes on turn-on in order to protect them from damage and extend their life).
  • Four NOS Sylvania twin-triode 6CS7’s for the first-stage of amplification (my favorite NOS 6CS7, but getting hard to find).

CS-600 tube complement.

NOS Sylvania twin-triode 6CS7’s.

NOS General Electric 6Cj3/6DW4B.

I should point out that with the 5881 power tubes the CS-600 is good for 32 watts, and with EL34’s 28 watts.

That’s not a lot of power, but the CS-600 is able to effectively drive even less sensitive speakers like my Harbeth’s quite easily, and with the sensitive Altec A5 Voice of the Theatre loudspeakers it’s more than enough!

Sophia Electric EL34-ST vacuum tubes in place in the CS-600.

I powered down the CS-600, removed the 5881 tubes, flipped the cathode resistor & plate voltage switches to their EL34 settings, and installed the Sophia Electric EL34-ST vacuum tubes in the CS-600.

Sophia Electric EL34-ST vacuum tubes in operation.

I powered back up the Leben CS-600 with the new complement of Sophia Electric EL34-ST tubes and let it warm up.

Sophia Electric EL34-ST tubes peeking out over the top of the Leben CS-600.

The Sophia Electric EL34-ST tubes are too tall to be able to put the top back on the CS-600, so it’ll be going topless for a while.

The Sophia Electric EL34-ST vacuum tubes are the very last review in my review queue right now, so it’ll be quite a while before their review for Positive Feedback will be ready, but that’ll give me plenty of time to interview Richard about their construction and his inspiration for their design.

Sophia Electric™ EL34-ST vacuum tube.

As I get some time on them and get a handle on how they’re performing, I’ll check in from time-to-time with an update on their performance in the Leben CS-600.


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

 Posted by at 6:32 am