Sep 172017

This morning I built a 1-meter shielded Duelund DCA26GA tinned-copper interconnect (shield connected at source end) to connect the 2-Ohm version of the Arai Lab MT-1 SUT that I am currently reviewing for Positive Feedback to my vintage MX110Z preamplifier’s phono stage.

Arai Lab MT-1 SUT.

I now have shielded versions of the DCA16GA, DCA20GA, and DCA26GA tinned-copper interconnects built up so that I can use them with different cartridges to get the best ‘voicing’ match possible for a particular phono cartridge.

Ortofon SPU Classic GM MkII

The Arai Lab MT-1 SUT was designed specifically for a cartridge with 2-Ohm impedance, like my Ortofon SPU Classic GM MkII, that I have mounted on the Woody SPU tonearm.

50 Guitars

I’ve been having a ball listening to Tommy Garrett’s 50 Guitars albums produced back in the 1960s. The concept of the various 50 Guitars albums is similar to that of the classic audiophile album, Music for Bang, Baaroom, Harp, on RCA Living Stereo, except the focus is on guitars.

50 Guitars Go South of the Border

All of the 50 Guitars albums I have heard so far are recorded superbly, in that audiophile “spectacular” fashion that was so popular in the 1960s, which the Liberty Premier label refers to as “visual sound”.

As a bonus, you can pick up 50 Guitars albums like the 50 Guitars Go South of the Border (above) out on Discogs inexpensively.

50 Guitars Go South of the Border

I listened to 50 Guitars Go South of the Border with the 2-Ohm Arai Lab MT-1 SUT and the shielded Duelund DCA16GA interconnects, first (which I have been using all along with my Ortofon SPU Classic GM MkII), and it was an excellent match, as I suspected it would be.

Then I listened to 50 Guitars Go South of the Border with the 2-Ohm Arai Lab MT-1 SUT again, with the shielded Duelund DCA26GA interconnects I just built replacing the DCA16GA interconnects.

Collings Waterloo WL-14L (left) Gibson Advanced Jumbo (right).

The sound with the shielded DCA26GA reminded me of what I heard when I first strung up my Collings (above, left) with a new set of Martin SP Custom Light strings, with it sounding a little lean, a little forward and aggressive, a little “bluesy”.

The Martin SP Custom Light strings are settling down now and mellowing a bit, and I suspect the Duelund DCA26GA will do the same, particularly after a little voltage conditioning on the FryBaby2.

DCA16GA (left), DCA26GA (right)

In contrast, the shielded DCA16GA IC’s were more analogous to what I hear from the Martin Medium SP strings I use on my Gibson Advanced Jumbo (above, right), being vibrant in the midrange, rich, nice and smooth treble response, dynamic, colorful, and a warmer overall presentation that makes everything sound great!

I also gave the shielded Duelund DCA20GA interconnects a listen with the 2-Ohm Arai Lab MT-1 SUT and the Ortofon SPU Classic GM MkII, and it was an excellent match to, just as it was with the Murasakino Musique Analogue Sumile phono cartridge.

Although, with the Ortofon SPU Classic GM MkII, I think the DCA16GA interconnect is a better match overall, with it’s dynamic, colorful, and dramatic presentation, which goes wonderfully well withOrtofon’s overall presentation.

The opposite is true of the Sumile, with its amazing resolution of nuance, dynamic gradations, and tone colors, it is better served by the Duelund DCA20GA.

It sure is nice to have some cable options to choose from though, as it really helps get the best voicing out of each phono cartridge possible.

Ok, well that’s it for now, I’ve got to get back to writing up the review of the Arai Lab MT-1 SUT for Positive Feedback.

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

 Posted by at 12:41 pm
Sep 152017

Man, the last couple of weeks have been rough. A kidney stone that seems to think that playing hide and seek with me is a fun thing to do has been keeping me under the weather a bit, and as a result I haven’t got nearly as much written as I like to.

No worries though, as the urologists like to say, “This too shall pass.” Such is the cycle of life.

Collings Waterloo WL-14L (left) and Gibson Advanced Jumbo (right).

As I mentioned some posts back, after a number of years hiatus from the guitar, so I could take care of my Mom and Dad when they were going through a rough time health-wise, I’ve picked back up my guitars and started playing again.

To celebrate my return to the guitar, I decided I wanted a smaller, comfortable guitar to play as I was getting back up to speed, and I picked out a Collings Waterloo WL-14L which arrived yesterday courtesy of Rainbow Guitars in Tucson, Arizona.

As I posted a day ago on Facebook:

“On the left is my very basic Collings Waterloo WL-14L, and on the right is my snazzy Gibson Advanced Jumbo in Brazilian Rosewood / Adirondack Spruce (above).

Originally I was looking for a nice old vintage Gibson LG-2 3/4 like Woody Guthrie gave his son Arlo to play, thinking it would be a nice small body guitar that would be a comfortable guitar to play when I’m sitting around on the couch relaxing.

Public domain photo of Woody Guthrie in 1943 with his Gibson LG-2 (I think it’s the LG-2).

I couldn’t find an LG-2 so I started thinking about alternatives. Then I heard about Collings’ Waterloo WL-14L and got intrigued. The WL-14L is similar in concept to an LG-2, a nice small mahogany / spruce body, and 14 frets to the body, which makes it more playable for jazz, as well as the blues, rock, and folk that it is an obvious good fit for.

Collings makes beautiful guitars, and I really like my OM2C, which is a very finely crafted guitar. But they’re expensive.

The WL-14L is Collings’ version of a minimalist vintage-style guitar kind of like the LG-2, and is relatively inexpensive as Collings go, being only a couple thousand.

The WL-14L is nicely finished with a nitrocellulose lacquer, but is not ornate, and is in fact a bit ‘rustic’. Instead of the Waverly tuners that I prefer, the WL-14L has simple but serviceable tuners. It has a bone nut & saddle, ebony bridge pins, and I chose vintage-style L-bracing and a carbon fiber T-bar instead of an adjustable truss rod.

The WL-14L is very lightly built, the build quality is all Collings, and with just a carbon fiber T-bar, it feels light as a feather in your hands.

It came setup perfectly, plays great, is super comfortable to play, is responsive, and is absolutely effervescent with life and great tone. Collings really hit a home run with the WL-14L!”

Gibson Advanced Jumbo (left), Collings OM2C (middle), and Collings Waterloo WL-14L (right).

I’ve picked back up my guitars, re-memorized the notes on the fretboard, refreshed my memory on the movable Major scale forms at every position on the neck, and have started committing all the movable jazz chord forms back into memory, which is a daunting task, albeit slightly less daunting than I was expecting.

I’ve also been working on technique a bit with Travis picking, jazz chord melody, etc., and just generally trying to get my brain and hands working again. It’s fun!

Arai Lab MT-1 step-up transformer for moving coil phonograph cartridges.

I’m writing again this weekend on my review of the Arai Lab MT-1 step-up transformer for Positive Feedback and hoping to make some progress on that front.

Duelund DCA26GA IC’s with Switchcraft RCA’s.

Last weekend I started building a shielded version of the Duelund DCA26GA IC’s to try for a SUT to preamp connection and bungled it. I was just a bit too under the weather to focus, so I’ll try again this weekend.

Audio Musikraft hot-rodded Denon DL-103 moving coil cartridge.

I’ve also really been wanting to get some more time in on Guy’s Audio Musikraft cartridge, but other than just some general listening (sounds great!) I haven’t had a chance to experiment with it’s voicing options, which I’m really eager to do.

Artisan Fidelity long-base plinth for the Thorens TD124.

Artisan Fidelity Thorens TD124 long-base plinth in progress.

My Artisan Fidelity Thorens TD124 Statement turntable is taking longer to get finished up than I and Christopher anticipated, so I’m moving Guy’s Audio Musikraft phono cartridge up in my review queue to right after the Arai Lab MT-1 SUT.

Christopher sent me a couple of photos of the plinth that you can see above, and said, “Your plinth is nearly finished with the last of the labor intensive final clear coat buffing process. Part of the delay is a result of recently implementing a high tech, state-of-the-art European acrylic urethane clear coat spray finish which requires some special application and handling techniques in order to achieve long term stability and to extrapolate the most durability and beauty from the Cocobolo’s breathtakingly beautiful wood grain finish.  After seeing the initial results with my own eyes, I wanted to implement this amazing, crystal clear, shimmering finish on your personal plinth, which although took a little longer than expected to cure, I am absolutely confident will be well worth the wait.”

I’ve got an exciting review coming, probably early 2018, of something very cool and new from Nelson Pass’s First Watt.

I’ve mentioned in a couple comments how great the trend is to see ultra-high performance products at affordable prices, like with Duelund DCA tinned-copper wire, Collings Waterloo WL-14L guitars, and Nelson Pass’s First Watt amplifiers.

I’m pretty excited about my upcoming First Watt adventure, as I’ve always enjoyed the combination of musicality and sonic prowess that Nelson’s designs achieve. I’m pledged to secrecy at the moment, but when I can I’ll tell you more.

Ok, that’s it for now.

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

 Posted by at 11:07 am
Sep 072017

Last weekend was a rough one. I was felled by a kidney stone on Sunday, which earned me a ride in an ambulance to the emergency room. The little bugger hasn’t passed through yet, and still has some fight left in it, which it has been keen to remind me of from time to time. Ugh. I’ve been singing the kidney stone blues!

Artisan Fidelity Thorens TD124 Statement Short Base turntable.

But on to more fun topics, like the Thorens TD124 restoration project that Christopher Thornton is building up for me in the form of his no-holds-barred Artisan Fidelity Thorens TD124 Statement “Long Base’ turntable, which I am very excited about. It’s getting close to being done and I am thrilled about it!

That’s the short base version of the Artisan Fidelity Thorens TD124 Statement turntable in the photo above, and my long base version will be similar, but about 3-inches wider to accommodate the 12-inch tonearms that I prefer.

Swiss Precision by Joachim Bung!

One of you recommended that I should study up on the history of the Thorens TD124 turntable by reading Joachim Bung’s excellent book Swiss Precision, which incidentally just arrived.

I’ve started reading Swiss Precision while I’m working through the kidney stone blues and it is a wonderful read! If you have a TD124 you owe it to yourself to get a copy of this book!

Quite a few of you have asked me which one I thought was better, the Garrard 301 or the Thorens TD124.

Guys, what kind of crazy question is that? It’s like asking, “Which is more fun to drive, a 1957 Chevrolet Corvette C1 convertible or a 1957 Ford Thunderbird convertible?”

The answer is obvious! The best one is whichever one you’re driving at the moment!

In fact, one of my fondest automotive memories was driving a restored ’57 T-Bird convertible with the music blaring and the wind blowing through my hair! (Yeah, it was a while ago!)

Sophia Electric Aqua 274B rectifiers in my vintage McIntosh MC30 monaural amplifiers.

I’d like to say a big “Thank you!” to Richard and Sue at Sophia Electric for leaving the Sophia Electric EL34-ST and Aqua 274B vacuum tubes with me on long-term loan after the review of them at Positive Feedback that was just published.

I know a lot of you are interested in these particular Sophia Electric tubes, and it was really nice of Richard and Sue to leave them with me so I could report to you on their long-term performance.

As I said in their review, there’s nothing in my NOS and new production tube stash that is in the same league as the new Sophia Electric EL34-ST and Aqua 274B vacuum tubes, they are in a whole ‘nother league musically and sonically from anything in my experience.

I’ll tell you what, when it comes to voicing vacuum tubes, Richard and Sue have particularly good taste, and early feedback to me from users in the field has been very positive.

Duelund DCA26GA IC’s with Switchcraft RCA’s.

I made a little bit of a mistake. After reporting on the positive performance of the Duelund DCA26GA IC’s in my main system, I put them on my FryBaby2 for a little bit of voltage conditioning of the dielectric.

Duelund DCA26GA IC”s on the vintage McIntosh MC30 monaural amplifiers.

I was thinking I’d do some voltage conditioning for about 12-hours, then give them another try. Well, I got distracted by the kidney stone thing and let them cook quite a long time. I actually lost track of how long.

I pulled them off the FB2 and gave them a listen and they were very laid back sounding. That could be a good thing depending on what you’re trying to do with system voicing, but I overdid it.

So I pulled them out of the Westminster system and put them on my OPPO UDP-203 Blu-ray player in my vintage Altec A5 Voice of the Theatre based AV system for a little cool-off time, and put a pair of Duelund DCA20GA interconnects that I had cooked for about 20 hours with voltage conditioning into my Westminster music system between my MX110Z preamp and MC30 monaural amps.

Whoa! The DCA20GA with 20 hours of FB2 voltage conditioning is stunning! Musicality to the heavens, as well as superb sonic performance!

Duelund DCA20GA interconnects.

This whole Duelund DCA tinned-copper cable experience has been so illuminating! It’s amazing what you can do with system voicing using different DCA gauge sizes and a little voltage conditioning with a FryBaby2.

It’s really been fun, and being able to experiment and dial in voicing just the way I want it has been really liberating and exciting for me.

Maybe the best part of it all is that the Duelund DCA is inexpensive as high-performance audio goes, so you can experiment and have fun without sweating about the cost.

Arai Lab MT-1 step-up transformer.

Assuming I’m able to write this weekend, my plan is to get started writing the Positive Feedback article about the Arai Lab MT-1 step-up transformer. It’s exotic, it’s expensive, it’s ridiculously good, and I’ll tell you all about it in the near future.

In the meantime you can get a glimpse of its performance by reading the Positive Feedback article I wrote about the Murasakino Musique Analogue Sumile MC phonograph cartridge in Issue 92 (below).


I’ve also really been enjoying my preliminary listening with the highly adjustable Audio MusiKraft hot-rodded Denon DL-103 MC phonograph cartridge.

I’ve been having fun building up Duelund DCA26GA and Art of Tone 24GA headshell leads to try with it, and I’m impressed with what I’m hearing.

Audio Musikraft hot-rodded Denon DL-103 moving coil cartridge.

I’ve also got something really exciting to tell you about that will be coming in the next few months. It’s a secret for now, but stay tuned, as it’s something really cool and coming soon!

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

 Posted by at 7:10 pm
Sep 022017

As I mentioned in a post about 3 weeks ago, I built up a set of 1.5 meter Duelund DCA26GA interconnects terminated with Switchcraft RCA’s.

Duelund DCA26GA IC’s with Switchcraft RCA’s.

I’ve been listening to the Duelund DCA26GA IC’s with the Switchcraft RCA’s on my OPPO UDP-203 Blu-ray player, and I’ve been impressed with how good they sounded in that application.

I had presumed that DCA26GA would be kind of small for line level signal amplitudes, but I’m glad I gave them a try that way, as they sound great as line level interconnects on the OPPO.

Duelund DCA26GA IC”s on the vintage McIntosh MC30 monaural amplifiers.

But how well would they work as line level IC’s in my main music system with the Westminster’s?

So this afternoon I decided to install the DCA26GA interconnects in place of my DCA20GA interconnects between my vintage McIntosh MX110Z tuner-preamplifier and my vintage McIntosh MC30 monaural amplifiers.

As a reminder, the Duelund DCA26GA wire uses 1 strand of 0.40mm diameter tinned-copper wire, and the Duelund DCA20GA cable uses 26 strands of 0.15mm diameter tinned-copper wires.

Bill Evans’ “Some Other Time”.

I had been listening to Bill Evan’s Some Other Time album with the DCA20GA IC’s this afternoon when I made the switch to the DCA26GA IC’s.

I thought I knew what would happen, which is that the DCA26GA interconnects would sound very spacious, but a little bit lean, but that’s not what happened.

If anything the DCA26GA interconnects sounded a little bit warm and rich, which is not at all what I was expecting to hear from them.

I think everyone knows by now that the Duelund DCA20GA makes for ridiculously good interconnects, and I’ve been using the shielded DCA20GA interconnects from the Arai Lab MT-1 SUT (in for review, and up next) to my vintage MX110Z preamplifier with superb results, and as unshielded interconnects from my MX110Z to my vintage McIntosh MC30 monaural amplifiers with equally superb results.

Eric Johnson’s “Europe Live” album.

Eric Johnson’s Europe Live album sounded spacious, silky, warm, natural, detailed, and transparent with the Duelund DCA26GA interconnects, and very, very, musical in the way that dynamics, tempos, and melodies were presented.

I haven’t had enough time to make any detailed comparisons of the DCA20GA vs. the DCA26GA as interconnects, but I thought both of them sounded great.

Given the DCA26GA is only $5.50 USD per meter, and Switchcraft 3502AAU RCA’s are just $3.99 each, you could make up a pair of one meter DCA26GA interconnects for less than $40 USD, which is an incredible bargain.

I like what I’m hearing so much that I’m going to build up a set of shielded Duelund DCA26GA interconnects to try between the Arai Lab MT-1 SUT to MX110Z preamp connection so I can hear what the DCA26GA sounds like in that application.

Time to put an order in with Parts ConneXion for some more shielding (TCBRAID-70765) and cotton tubing (COTTUBE-72532) so I can make up some shielded DCA26GA interconnects!

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

 Posted by at 5:54 pm
Aug 272017

I wrote all day yesterday and finished up the review of the Sophia Electric EL34-ST and Aqua 274B vacuum tubes.

The Sophia Electric EL34-ST power tubes (above) and Aqua 274B rectifiers (below) outperformed everything that’s ever graced my Leben CS-600 integrated amplifier, and vintage McIntosh MC30 monaural amplifiers, respectively, and by a large margin.

I don’t know what makes these tubes sound so magnificent musically and sonically. I could be the contribution of the ST bottle shape, or the noise reducing blue glass, the design & materials of their internal structure, or Richard’s prowess in voicing tubes, but the Sophia Electric Aqua 274B rectifiers and the Sophia Electric EL34-ST power tubes are both home runs by Richard, and they are simply superb both musically and sonically.

Your can read the full review here.

 Posted by at 11:00 am
Aug 262017

As I mentioned in an earlier post, I laid down my guitars a few years ago and haven’t played them since then, as the focus of my time was helping my Mom and Dad through some difficult times healthwise.

I decided I needed to pick the guitars back up as I was really missing that in my life, so I got back out my guitars and have been practicing and playing again.

It’s taking some effort to shake off the mental cobwebs and get the fingers & hands back into shape, but I’m really enjoying the journey.

I’ve been mostly playing my acoustics up until today, when I was playing / practicing a little jazz chord melody style on my Eastman archtop and Henriksen Jazz Amp.

Jazz chord melody style is a challenging but satisfying way to play guitar, because you’re playing chords / harmony and the melody line at the same time.

It turns out that Mark Coles (Sablon Audio) just sent me an email to say “Hi!” and see what was going on, and to tell me that he might be able to offer some of his Gran Corona power cords at a considerable savings due to the effects of Brexit.

“Over the past few days, I’ve been having a much overdue spring clean and found sufficient materials to offer another batch of Gran Corona … Given the fall in the value of GBP following Brexit, I have been able to reduce the selling price to $750. Should sufficient interest be shown, then I may reintroduce this model.”

As most of you know, Mark’s Gran Corona is one of my all-time favorite AC power cords, and as I’m doing reviews it is one of a couple different AC power cords that I swap in and out while I’m dialing in the voicing for sonics and musicality.

Like everything else in audio, what AC power cord is best for a particular set of components in a setup varies, so it’s nice to have a couple of different power cords so you can get the voicing just right.

Currently my two favorite AC power cords are Mark’s Gran Corona and the Acoustic Revive Power Reference TripleC NCF.

The Acoustic Revive Power Reference TripleC NCF is $5750 USD, so $750 USD for a Gran Corona is a steal. If you want one you better act fast, as quantities will be limited.

Anyways, Mark’s email gave me the idea that I should try a Gran Corona on my Henriksen Jazz Amp.

Holy moly! Mark’s Gran Corona totally transformed my Jazz Amp, the tone I’m getting from my archtop is just blowing me away!

I sent Mark an email to tell him about it.

“Guess what? A Gran Corona makes as much difference on a guitar amp as it does on an audio amp. That’s pretty cool! Maybe you should consider doing a little marketing to the guitar player market, as there are way more electric guitarists than there are us of audio nuts!”  

I’ll tell you what, guitarists should consider following the high-performance audio lead and give a premium power cord a try, I think most guitarists would be stunned by improvement a quality AC power cord like the Gran Corona brings to the music.

Ok, back to the music, I was just so thrilled about the result of using the Gran Corona on my Jazz Amp that I had to tell you about it.

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

 Posted by at 11:11 am
Aug 252017

I’m hard at work listening and writing this weekend for my article about the Sophia Electric EL34-ST and Aqua 274B vacuum tubes for Positive Feedback.

I hope to be finished up with the article either this or next weekend, but I thought in the meantime you might enjoy a sneak peek, so here you go!


Sexy Blue Tubes: The Sophia Electric EL34-ST and Aqua 274B Vacuum Tubes!

By Jeff Day

I’ve always enjoyed visiting with Richard and Sue at Sophia Electric about their vacuum tubes and amplifiers, so when Dr. David contacted me about Sue’s inquiry to see if I’d be interested in writing about the new Sophia Electric EL34-ST and Aqua 274B vacuum tubes, I said “You bet!”

I’ll start with the new Sophia Electric EL34-ST, but before I go into any details about it, I think I should begin with a little preliminary history about the EL34 style of vacuum tube, so that Richard’s goals for the Sophia Electric EL34-ST can be understood in context.

Beam power tetrode tubes like the RCA 6L6 (1936) were popular in the vacuum tube marketplace in the 1940s. The European EL34 pentode vacuum tube developed by Philips in 1949, which was the parent company of Mullard, and Mullard would release their EL34 in 1953.

It has been speculated that the development of the EL34 was a way to circumvent the patents held by America’s RCA on beam power tubes. Although, it has also been reported that RCA developed the 6L6 beam tetrode tube as a way to circumvent the even earlier Philips patent for the pentode tube design, which indicates intense corporate competition for a valuable vacuum tube market.

While there are differences in the internal construction of a 6L6 beam tetrode and an EL34 power pentode, they are functionally similar, and have a similar range of power output, but distinctly different tone, which has come to be characterized as “American tone” vs. “British tone”.

Public domain photo from Wikipedia commons.

The intent of the Mullard EL34 was to produce an inexpensive tube that could achieve high power with high-sensitivity, allowing designers to develop amplification with a minimum of components to help keep costs down.

Mullard assisted designers by providing a wealth of information about incorporating their vacuum tubes into audio preamplifier and power amplifier designs in the Mullard Circuits for Audio Amplifiers (1959), which is fascinating to read, by the way.

The EL34 was rapidly embraced in for both audio and guitar amplifiers, with notable audio designs employing the EL34 like the Marantz Model 2, Model 5, Model 8A, Model 8B, and Model 9 amplifiers, and the very popular Dynaco Stereo 70. The EL34 was introduced into the guitar world when Marshall introduced it into their production guitar amplifiers, like the JTM 50 (1966) and JTM 45 (1967).

For those of you interested in learning more about EL34 vacuum tube history, I recommend you take a look at the Mullard Circuits for Audio Amplifiers, and in particular I encourage you to read Eric Barbour’s two excellent articles about the history of the EL34 vacuum tubes in Vacuum Tube Valley Issue 2 and Issue 16.

The Sophia Electric EL34-ST Vacuum Tube

I asked Richard if he’d tell us about how his Sophia Electric EL34-ST compared to the classic EL34’s, and what he’s done different.

Sophia Electric™ EL34-ST vacuum tube.

“The origins of EL34 tubes can be traced back to Europe during the late vacuum tube era. Its creation was to fulfill the purpose of being easily mass produced during a time when cost cutting was important, and this resulted in many limitations being placed on the tubes.”

“The EL34 tube is important, because with the resurgence of vacuum tubes in the 1990s, the EL34 tubes also regained worldwide popularity in thanks to its low drive voltage requirement that was sufficient for 20-35 watts per channel of power output for home use.”

“Eastern European, Russian, and Chinese vacuum tube manufacturers have all taken the original European EL34 as the basis for their designs, and have replicated it in massive production without pondering the “whys” and “hows” of that original design.”

“The EL34 design is an industrial tube, using a straight glass pipe sliced into cylinders on the assembly line for fast production. The shape of the tube, known as GT shape, was never considered for its sound quality. In other words, by making the EL34 tubes the same way they were originally created, the quality of the sound is sacrificed for the sake of time and profit.”

“We think of Sophia Electric as an innovative American company, and thus we aim to redesign well known products like the classic EL34 design, to improve especially upon the sound quality. In the process of designing our high-performance 126S amplifier, we rediscovered the use of EL34 tubes for replacing the Western Electric 350B/6L6 in the classic WE 124 amplifier circuit that we started with. But we really wanted high-quality tubes to pair with our new amplifier, so we decided it was vital to redesign a brand new EL34 tube to create the ultimate in sonic performance for our new 126S amplifier.”

“The original EL34 tube is a pentode power tube design that is known for bright, direct, and somewhat straight-in-your-face sound.  When the EL34 tube is pushed too hard it generates an excessive amount of distortion, which is good for rock & roll guitar amplifiers, but not for high-end audio amplifiers.”

“So we designed our new EL34-ST to be closer to the European KT66 family of tubes, yet we still wanted to retain the key characteristics of the original EL34 tube design.  Our new design replaces the original EL34’s plain and rather uncivilized sound with a more refined and artistic sound. The EL34-ST is articulate, yet still lyrical. It has more micro-contrast in the nuance of the music, and more vividness in the 3-D stereo soundstage that audiophiles enjoy.”

“Electrically the specifications of the EL34-ST are same as the vintage Mullard, with a heater (filament) voltage of 6.3V AC, a heater current of 1.5A, a maximum plate voltage of 800V, and a maximum power dissipation of 25 watts.”

“As a result, Sophia Electric’s new EL34-ST tube is a direct replacement for vintage Telefunken and vintage British made Mullard EL34 tubes.  It is also a safe direct replacement and premium upgrade choice for amplifiers currently outfitted with Chinese, Russian (the current “Mullard” is a Russian tube), and other Eastern European EL34 tubes.”

“The vintage EL34’s utilized a GT shape glass enclosure that was cheap and simple to mass produce. In the production line, each glass tube was created like a long sausage being sliced.”

“For the Sophia Electric EL34-ST we chose to use an ST shaped glass bottle similar to those used for 300B’s, which helps give the EL34-ST a 300B-esque sound. In fact, we applied much of our 300B design and manufacturing expertise in the creation of our new EL34-ST vacuum tube. The larger ST bottle shape gives our EL34-ST tubes a sound that is more airy and live-like compared to the cheap GT glass tube.”

“The blue tint that we’ve added to the glass not only looks exotic, but during the voicing process we found that the blue tint of the ST shaped enclosure added more sonic impact to the presentation of the music.  Vintage US military tubes often had a black metal base and/or black-grayish smoky carbon-containing paint sprayed on the inside of the glass tubes for light shielding to reduce noise. British and German military tubes often used red paint for light shielding to reduce noise.  We have auditioned various light shielding possibilities, and ultimately settled on the blue tinted glass, which when combined with ST bottle shape, provided additional musicality and a distinctly better tone.”

“Back when all vacuum tubes were placed inside a chassis, there was no need for consideration about light induced noise.  However, high-performance audio enthusiasts now like to see the tubes displayed in the open, so they can see them from their listening seats, and they also enjoy seeing the glow of the filaments. The blue tint ST bottle shape is an ideal solution, as it is a beautiful and excellent sounding bottle shape, and the blue tint offers the benefit of a reduction in light induced noise, while still allowing the listener to see the beautiful glow of the filaments.”

“We are confident that those who have an EL34 amplifiers would be thrilled with this brand-new patented Sophia Electric EL34-ST tube.”

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

Sophia Electric offers the following pricing options for the Sophia Electric EL34-ST tubes:

Grade A (top 10%): $125 USD per tube with 30 days warranty, $25 extra for one year warranty.

Grade B (top 25%): $100 USD per tube with 30 days warranty, $25 extra for one year warranty.

As points of comparison, a matched pair of vintage EL34 Mullard nickel base tubes with an early production 1956 date code (the most desirable vintage Mullard EL34), sell for $499 USD per matched pair at Brent Jesse Recording (when available), and the new production “Mullard” (the name and trademark were acquired by New Sensor Corporation) that are manufactured in the Reflektor factory in Russia, typically sell for around $26 USD per tube.

So, the vintage 1956 Mullard EL34 at about $250 USD per tube, is about ten times more expensive than the mass production Russian Reflektor EL34 at $26 USD per tube, the new Sophia Electric EL34-ST at $125 USD per tube is about five times more expensive than the mass produced Russian Reflektor EL34 per tube, putting the Sophia Electric EL34-ST towards the middle of the pricing spectrum between current production Russian Reflektor EL34’s and the vintage 1956 Mullard EL34’s.

Sophia Electric told me that the Sophia Electric EL34-ST tubes are rated to have a mean life span of 7,000 hours, with a range of 5,000 – 10,000 hours, which translates to about a four to eight-year lifespan, with a median of just under a six-year lifespan, assuming about 1,200 hours per year of operation.

The Sophia Electric Aqua 274B Rectifier Tube 

The original 274B rectifier tube was developed by the legendary Western Electric company in America. The Western Electric 274B is filamentary full-wave rectifier with an octal base that delivers direct current from an alternating current source.  You can read the full specifications of the WE274B here, in the Western Electric Vacuum Tube Data Manual (1941).

I asked Richard if he would tell us about his Sophia Electric Aqua 274B rectifier tube, and how it compares to the original Western Electric 274B rectifier tube.

Sophia Electric Aqua 274B Rectifier.

“Prior to Aqua 274B rectifier tube, Sophia Electric has made a number of successful 274B rectifier tubes, like the Princess 274B mesh plate, which we consider “the ultimate choice” for today’s high-end tube pre-amplifiers and headphone amplifiers, as well as for small triode (2A3/45/PX4/71A/205D/101D) tube mono-block amplifiers.”

“Our Princess 274B rigid plate rectifier tube is a true replica of the vintage Western Electric 274B rectifier tube.  Many audiophile users have reported that it sounds better than the original vintage Western Electric 274B in the WE91 300B circuit, or in a modern 300B single-ended tube amplifier circuit, and at a fraction of the cost.”

“However, all traditional 274B rectifier designs (Sophia or Western Electric) have the limitation that the first capacitor in the power supply after the rectifier tube must be miniscule. For vintage Western Electric 274B rectifier tubes it can be no bigger than 4 uF, and for the Sophia Electric rigid plate and mesh plate 274B’s the limit is a slightly higher 8 uF.  No matter how great those 274B tubes sound, this capacitor requirement limits 274B applications, just as it did for the original Western Electric 274B rectifier during the golden age of vintage vacuum tubes.  Mainstream rectifier tubes like the 5U4 (America) and 5AR4 (Europe) permit up to 47 uF in the first capacitor position in a power supply, making them applicable to a wider variety of power supply designs.”

“So why bother with a 274B rectifier? Back in the early 1930’s Western Electric designed the WE91 cinema amplifiers that utilized the 300B tube in a single ended output circuit. The WE91 produced an output of 5.6W, which was enough to drive the cinema horn loudspeakers of the 1930’s to volume levels adequate for cinema sound reproduction. 300B tubes require about 60V RMS drive voltage to achieve their full output power of 5.6W.  To accomplish this, Western Electric chose the 310A, a pentode tube, for their driver choice.”

“The pentode driver tube was an elegant choice, but it was at the expense of high frequency extension.  Back then, 10KHz was considered the maximum high-frequency for high-fidelity, with movie dialog being more in the mid-range.  Even so, Western Electric still wished for a little more high-frequency extension in their WE91 300B amplifier to make the sound more open and lively.  This demand called for a premium long plate rectifier tube, now known as the WE 274B tube.”

“Without the 274B rectifier tubes, Western Electric tube amplifiers sounded rather dark and dull.  But with the 274B, Western Electric amplifiers sounded full and complete, and were a significant sonic upgrade.”

“However, when the power supply capacitor is higher than 8 uF the long plate of the WE274B sparks, which forced Western Electric to limit the design requirement to 4 uF.  This limitation prevented the 274B rectifier tubes from being used in a wide variety of applications, both in vintage times and today, as most modern equipment was designed with up to 47 uF capacitors as the first capacitor in the power supply so they could utilize 5U4G and 5AR4 rectifiers.”

Sophia Electric™ Aqua 274B rectifier tube.

“Sophia Electric has solved this limitation of the 274B in our Aqua 274B rectifier tube. Initially we tried to solve this limitation by using exotic materials, as in the design of our very popular Royal Princess 300B tubes, which utilizes platinum and rare earth materials.  We were successful, but the finished product was way too expensive for the average consumer to be viable.”

“Then we went back to the WE 274B structure design as a starting point, and in an unexpected way we figured out a way to solve the Western Electric limitation of 4uF. This solution allowed us to build the Sophia Electric Aqua 274B, which can use up to a 47 uF filter capacitor value, the same maximum value permitted for 5U4 and 5AR4 rectifiers.”

“In a 300B mono-block amplifier, such as Sophia Electric’s 91-01, or the newer 91-01 Signature amplifier, the Aqua 274B can easily replace the 5U4 rectifier tube and deliver a wider and deeper soundstage, and deliver the musical magic that is otherwise missing when not using a 274B rectifier.”

Sophia Electric™ Aqua 274B rectifier tube.

Sophia Electric offers the following pricing options for their Sophia Electric Aqua 274B rectifier tubes:

Option 1: $199.99 per tube with one year warranty

Option 2: $159.99 per tube with 30 days warranty

As interesting data points, original vintage Western Electric 274B rectifiers are currently selling for $1499 USD each at Brent Jesse Recording, and the mass production Chinese Shuguang 274B rectifier sells for approximately $27 USD each on the open market.

So, a vintage Western Electric 274B rectifier sells for approximately fifty-five times the price of a mass production Chinese Shuguang 274B rectifier, and the Sophia Electric Aqua 274B rectifier sells for about six times the price of the Shuguang 274B rectifier.

Sophia Electric doesn’t have a lot of data on the lifespan of the Aqua 274B yet, as it is a new tube for them. However, based on earlier 274B rectifier track records, Sue thought it likely that it would have a 5,000 to 10,000-hour lifespan, with the caveat that the amplifier has no more than a 47 uF capacitor in the power supply after the rectifier.

If you are unsure about the value of the first capacitor in your amplifier’s power supply, ask the manufacturer about it. For example, in my vintage McIntosh MC30 monaural amplifiers, in which I’ve hot-rodded the power supply a bit in an adventure with Yazaki-san, the first capacitor after the rectifier is a 0.47 uF Arizona Capacitors “Green Cactus”.

Listening Impressions


Ok, that’s it for now, and I hope you enjoyed it!

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

 Posted by at 11:47 am
Aug 212017

I’m really excited about a very special Thorens TD124 restoration and ‘hot-rod’ project I commissioned with Christopher Thornton of Artisan Fidelity.

The completed Artisan Fidelity TD124 Statement turntable will look similar to the photo below, but will have a “long-base” plinth that is about three inches wider to accommodate my preferred 12-inch tonearm.

Artisan Fidelity TD124 Statement.

Christopher just sent me some progress photos of the TD124 restoration, so I thought I’d share them with you.

These are progress photos of the TD124 Statement chassis, plus platter, plus clutch platter.


That’s a beautiful restoration of the Thorens TD124, Christopher!

Artisan Fidelity TD124 Statement turntable.

Christopher is doing finishing work on the long-base plinth now. Christopher’s plinth design features a mass loaded, constrained layer, damped, Cocobolo and Panzerholz core, with a grain matched Cocobolo armboard,  Stillpoints Ultra SS isolation feet on the bottom of the plinth, and a Schurter IEC inlet with shielded OFC Copper power cable to connect the Thorens TD124.

The completed Artisan Fidelity TD124 Statement turntable is getting closer every day! I’m excited!

For more information about this Artisan Fidelity TD124 Statement project you can read here and here.

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

 Posted by at 7:24 pm
Aug 202017

Everyone loves Western Electric it seems, and for good reason, as their vacuum tubes and audio designs are the stuff of legend!

I just ran across a fun film (below) from Western Electric about their vacuum tubes that was in the AT&T Archives, and I thought I’d share it with you.


A Modern Aladdin’s Lamp (1940)

This short video gives a nice introduction to how vacuum tubes work and are manufactured.

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

 Posted by at 11:24 am
Aug 202017

I have access to buying almost anything as an audio writer, and there’s some really nice audio gear out there, but for a preamplifier I chose the vintage McIntosh MX110Z tuner-preamplifier, which was sold by McIntosh from 1962-1969 for the lofty price of $399.

My beloved vintage McIntosh MX110Z.

The reason is that the vintage McIntosh MX110Z tuner-preamplifier is an example of one of the finest Golden Age preamplifiers you can buy, with perhaps the finest balance of musicality and sonics for my tastes that I have ever heard from a preamplifier, vintage or modern, along with the substantial bonus of having a terrific sounding and highly musical FM tuner and phono preamplifier.

Another thing I like about vintage McIntosh electronics is that they have the near equivalent of eternal life as an audio component, and it wouldn’t surprise me at all that through a thoughtful combination of maintenance and service that an MX110Z could play music for a century or more, delighting not only you, but your ancestors after you.

Mine’s been playing music now for over 50 years, and I expect that it’ll easily provide me musical pleasure for the rest of my life!

One service item that is easy to do in an MX110Z is quieting down a noisy volume potentiometer, which is a fairly common occurrence.

You’ll know you need to do some cleaning/lubing of your MX110Z’s volume pot when it starts sounding “scratchy” while changing volume, or “pops”.

I’ve also noticed that the volume potentiometer will let you know that it’s getting close to time for a cleaning/lubing by sounding a little harsh and edgy compared to it usual lush and liquid self.

When I contacted the McIntosh Customer Service Parts Department about a replacement volume potentiometer for my MX110Z, I was told “This part is no longer available and there is no substitute.”

I should point out that while McIntosh does not offer replacement volume potentiometers for the MX110Z, and as far as I know, no one currently manufacturers a suitable replacement for the factory version, all is not lost if your MX110Z’s volume potentiometer is getting noisy.

Why? Well most likely you can keep your potentiometer working longer than you might think with a cleaning/lubing with DeOXit.

I contacted vintage McIntosh specialist Terry DeWick to ask for a recommendation, and he told me, “I have had almost 100% success using Caig DeOXit F5 to clean the pots, depending on location, dust in the air, and humidity, a good cleaning is good from a year to 20 years.” Caig DeOXit F5 is available from Amazon.

There’s also a nice overview of using DeOxit for cleaning and lubing vintage gear out on Audiokarma, titled “The Idiots Guide to Using DeOXit“, that’s worthwhile reading through.

Nude and powered down MX110Z.

To lube/clean the volume pot on an MX110Z with DeOXit F5 you have to get access to the volume pot, which is fairly easy to do.

The steps are easy. Start with a nude and powered down MX110Z, as in the photo above.

Remove the 6 knobs for the input level adjust pots.

The first step is to remove the 6 knobs of the “Input Level Adjust Controls” potentiometers on top of the chassis, which you can see above and to the right of the volume pot.

Knobs with setscrews in the back.

Each knob has a setscrew on its backside that you loosen, and the knobs slide off easily.

Once you’ve removed all the knobs it’s time to remove the two sheet metal screws on each side of the chassis that hold the top cover in place.

Two sheet metal screws on each side of the top cover need to be removed.

You can see the two screws just above the socket in the photo above, and on the other side of the chassis in the photo below.

Remove the 2 sheet metal screws on each side of the chassis.

After you’ve removed the 4 sheet metal screws that hold the top cover of the chassis in place, the top cover lifts off easily, revealing the volume pot (below left).

The MX110Z’s volume pot revealed!

You can see the MX110Z’s volume pot on the left-hand side, just underneath the pulley for the tuner.

Add a little DeOXit F5 into the openings of the volume potentiometer.

Spray a little bit of DeOXit F5 into the three openings of the volume potentiometer, then work the volume pot through its full range of motion a couple of dozen times.

You’re done!

Also, if you wish, you can put a drop on each of the input level adjust pots and work them back and forth a couple of dozen times through their full range of motion. I’ve had the input level adjust pots for phono inputs get a little noisy too, and a drop of DeOXit fixed them right up!

Now put everything back together, and be sure to only tighten the sheetmetal screws on the sides of the chassis so they’re just a smidgen past finger-tight, or you could risk stripping them, which would be a major bummer.

Ditto for input level adjust pot knobs, just tighten them to a gentle finger-tight, as you don’t want to damage them, or you’ll be sorry!

A happy and quiet volume pot for your MX110Z is a wonderful thing!

Now power up your MX110Z and you should have a nice quiet volume pot, and the music should be more liquid and smooth sounding.

If you go through the lube/clean drill and your volume pot is still noisy, just give it another try and see if that does the trick.

If you can’t get your MX110Z’s volume pot quieted down, there’s a possibility that it’s worn out.

If that’s the case, not all is lost, as Audio Classics can rebuild your MX110Z volume potentiometer for $175 USD plus shipping.

I hope that proves helpful for you, and as always, thanks for stopping by!

 Posted by at 9:44 am