Mar 312017

I get really excited about vacuum tubes!

The new Sophia Electric EL34-ST vacuum tube.

When Sue and Richard at Sophia Electric contacted me about doing an article about their new Sophia Electric™ EL34-ST vacuum tubes I was quite intrigued.

I don’t know what it is, but every time I see a vacuum tube with the ‘ST’ style of glass bulb shape I just swoon, I think they’re gorgeous.

Not only that, but the new Sophia Electric™ EL34-ST vacuum tubes have a blue ST glass bulb. I don’t know anything about them yet, but if I know Richard, there’s a story there!

Quad of Sophie Electric EL34-ST vacuum tubes for the Leben CS600 integrated amplifier.

Jonathan Halpern had huge success winning ‘best sound of show’ praise (1, 2) with his Leben CS600 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.

What kind of vacuum tubes was Jonathan using in his Leben CS600 that garnered such impressive praise? If you guessed it was EL34’s you’re exactly right.

Sophia Electric™ EL34-ST vacuum tube.

So I thought it would be fun to try the new Sophia Electric™ EL34-ST vacuum tubes in my Leben CS600 integrated amplifier.

Sophia Electric™ Aqua 274B rectifier tube.

When I was out at the Sophia Electric web site checking out the new Sophia Electric™ EL34-ST vacuum tubes, I noticed that Richard & Sue are also now offering Sophia Electric™ Aqua 274B rectifier tube as well.

Sophia Electric™ Aqua 274B rectifier tube.

I’ve been fortunate in having some very lofty rectifiers to use in my vintage McIntosh MC30 monaural amplifiers, like the beautiful NOS Haltron 5U4G rectifiers that Yazaki-san sent to me to use for our vintage McIntosh adventure (and which I’m still using), or the RCA 5U4GA rectifiers I was using prior to their arrival.

Good stuff!

Sophia Electric™ Aqua 274B rectifier tube.

Some of you know that the Western Electric 274B rectifiers were upon the podium of the greatest rectifiers ever made in human history, a rectifier of the gods, and it appears that Richard wants to knock it off the podium with his blue glass Sophia Electric™ Aqua 274B rectifier tube!

Sophia Electric™ Aqua 274B rectifier tube in my vintage MC30 monaural amplifiers.

I put the blue glass Sophia Electric™ Aqua 274B rectifier tubes into my vintage MC30 monaural amplifiers, let them warm up for a few moments to make sure all was well after their long journey from Sue & Richard, then put on my Henry Mancini’s “Breakfast at Tiffany’s” LP.

The blue glass Sophia Electric™ Aqua 274B rectifier tubes in my vintage MC30 monaural amplifiers.

As the stylus touched down in the groove and the music began to play my jaw almost bounced off the floor!

The blue glass Sophia Electric™ Aqua 274B rectifier tubes caused lust bumps to pop up all over my body immediately upon first listen! And that was cold out of the box!

There’s a new King in town, the Sophia Electric™ Aqua 274B!

Normally I try to be a little bit reserved about first impressions, but … wow … just wow!

Some of you might remember the series of articles I did on Sophia Electric’s 300B vacuum tubes, culminating with an article about the top-of-the-line Sophia Electric Royal Princess 300B, I’ll be giving the new Sophia Electric™ EL34-ST and 274B rectifier tubes the full treatment, with interviews with Richard about his inspiration for their design, how they came to be, and how they perform.

Stay tuned, this is going to get really interesting!

As always, thanks for stopping by!

 Posted by at 4:55 pm

  22 Responses to “Today’s Fresh Catch: Sophia Electric EL34-ST & Aqua 274B Vacuum Tubes!”

  1. Jeff; you just keep adding to my “must try” list. I can’t even begin to keep up any more!
    Thanks…I think

    • Howdy George!

      I can bring the 274B’s over so you can hear them in your MC30’s.

      That is a bit dangerous though, in one use you could be hooked! 😉



      • Jeff; don’t need much of an excuse to get together; but this is a good one. Only a couple more days here in the Senora Desert. Will get in touch after we return to see just how tempting these are

  2. Hola Jeff.

    I’d suggest being a tad wary of those ST-shaped EL34’s. After 20+ years of repairing, building, tweaking & using EL34-based amplifiers, my first thought upon seeing the photos above were “Those’ll be microphonic as…”, closely followed by “those look like arc-overs waiting to happen.”

    They might survive for a while in your Leben, but don’t be suprised if they start sounding off & get crackly fairly rapidly…

    Anyhoo, I haz Flu, so thinking’s hard…

    Cheers… G
    (who iz aching)

    • Hi Gareth,

      I like the ST bottle shape, and I’ve had great results with it in 6L6, 45, 2A3, 300B, rectifiers, etc., and never had any issues.

      Maybe EL34’s are the exception to the rule, but that’s what reviews are for – I’ll find out! 🙂

      Get well soon, Gareth!

      All the best,


      • Hola Jeff.

        Feeling a bit more human today – my hair has stopped aching at least…

        The ST shape is fine to use for valves that are designed for it – not so fine if the valve was originally designed for a straight envelope. It’s a matter of support. ST designs have a top support mica, with the bottom of the electrode structure embedded in the glass of the envelope. Straight valves get much more support from the micas immediately above & below the plates, and tend to become microphonic if that support isn’t there.

        If Sophia have taken this into account & used heavier connecting wires from the base to the electrode structure, then there shouldn’t be a problem, but having heard a set of ST-shaped Sophia 6SL7’s* that squealed like a stuck pig at anything above “quiet listening” volume levels, I have my doubts…

        Cheers… (a slightly more human) G

        *- Coulda been 6SN7’s, pretty sure they were SL’s tho. Was annoying, as they sounded really nice when they weren’t squealing…

        • Glad to hear you’re feeling better, Gareth, there’s been some nasty stuff going around here too the last week or two.

          When I interview Richard at Sophie Electric for the review at Positive Feedback, I’ll ask him about how he’s addressed the potential microphonic issues of the ST bulb shape, and of course I’ll report on everything I hear them doing as well!

          Kind regards,


  3. Hello!
    Look forward to your impressions of these EL34’s! I have enjoyed the Sophia KT88 and 6SL7 blue bottles. After a couple months of heavy use, I’ve had zero issues. Stable and very low noise. I am considering a pair of 6SN7 for another project.

    Thanks again for all you do here.


  4. Funny how this discussion appeared in the same time frame as my experience with the same Sophia tubes. I run them in my KIT1-10 ( I also use the Sophia Royal Princess 300B’s). It’s been 3 months and not a sign of trouble. I like all these tubes; the Aqua Blue 274B made the strongest impression; the 6SN7 gives me tone to a higher power; the Royal Princesses are the best of three 300B sets I’ve used. My friend Stuart steered me to the Sophia tubes but he reports problems with his own tubes which have all been replaced under warranty. Tube karma is full of surprises, eh?
    We need you to pay a visit to my friend Jeff. He has a pair of Tannoys like yours but with the stock crossovers. The speakers are awesome and sonically impressive. I think Jeff could build Duelund external crossovers – he has the skills but is entirely content with the Tannoys , the ANK Mentor and ANK EL 34 mono blocks. The Mentor just makes the Tannoys sing; it proves the Tannoys can convey tone.
    Thank you for your inspiration and setting an example of fearless experimentation. And thank you to God for creating the internet where we can have a conversation about vacuum tubes while sipping coffee in the favourite chair.


    • Hi John,

      Thanks for the report on the Sophia tubes, appreciated!

      I have had no problems with my Royal Princess 300B’s, but both my friends Leo and George have had one of their pair of Royal Princess 300B tubes fail after a year, which in my opinion is much too soon for tubes that cost that much.

      It will be quite a while before I’ll be able to write up my review of the Sophia Electric tubes for Positive Feedback, so I’ll get plenty of hours on them before I write them up. If there’s any issues of short tube life I shall report on it.

      I thought the Duelund crossovers on my Westminster’s made a huge difference in performance, but my friend Leo, who also has Westminster’s, has opted to leave his West’s stock like your friend, Jeff.

      I get it, as they also sound great stock, and it is a big undertaking to do what I did for sure, but it was a fun one!

      Kind regards,


  5. Hi Jeff,

    I’m the Stuart that John Borda referred to. The first pair of Royal Princesses failed before the 30 day warranty. They were bought at the end of June 2016, so I was sent a new pair. I had purchased the Aqua 274b at the same time I bought the SERPs.

    I later purchased a 6SN7 about a month later. That failed after the 30 day warranty, so I was asked to pay $25 plus shipping for a replacement, which I did.

    On December 30th, the replaced SERPs failed again, along with the Aqua 274b. I was livid, but I kept my calm and just replaced the SERPs with my Shuguang Treasures, and the 274b with my Sylvania 6u4g. I have been listening to my amp with no issues whatsoever.

    I contacted Sue some time in March and sent the tubes back. She wants to put the blame on my Amp, an ANK Kit1. I pointed out to her that the only time Ive had any issues with my amp, was when one of their tubes failed. I have had the amp for just over a year now, with no other issues, except for failure from Sophia Electric tubes.

    I will be very honest and say the when their tubes worked, they produced tremendous sound. I was mostly impressed with the Aqua 274b, that made the biggest impact in the overall sound of my system.

    I have since bought a pair of Emission Labs 300 BLX , they have been working fine with no issues for the last month.

    Sophia Electric make great sounding products, but leave a lot to be desired when it comes to quality control.

    I’m awaiting replacement of the tubes at a lower cost, which is semi gratifying.

    It would be interesting to see what feedback you get when you interview Richard.

    Thanks for listening Jeff. I’ll write later on a more positive note regarding Duelund products.



    • Hi Stuart,

      I’m sorry to hear of your difficulties with tube failures and customer service issues related to Sophia Electric.

      Unfortunately, a number of other readers have communicated similar accounts to me about customer service issues when dealing with Sophia Electric.

      For whatever reason, when there is a Sophie Electric product issue, there seems to be a common response in first blaming the customer for the issue, before following through on assisting the customer with the issue.

      I don’t know why they do that, it makes them look terribly bad as a company, as people buying premium products for premium prices expect to be treated with courtesy & respect and have their issues addressed promptly.


      Kind regards,


  6. Hi Jeff, thanks for taking the time out to listen to my beef. This hobby of ours is a great one, it could be a lot nicer and smoother if we didn’t have encounter situations such as mine.

    Now I know when dealing with tubes, there are going to be some failures occasionally , but not at the rate that I have experienced with these, especially given the premium that I paid for them, and then to have blame directed at me, it can become quite frustrating and annoying.

    Needless to say I would not be purchasing their tubes again. There are other tube manufacturers that have better warranties and customer service , and quality control .



    • Hi Stuart,

      If you come across something particularly amazing, be sure to let me know!

      Kind regards,


      • Hi Jeff,

        I just want to ay that I just exchanged my duelund 16g interconnects for the 20g, and I really loved the improvement that it made in my system, in all aspects of it….no audiophile jargon here. It just has a rightness of sound in every way. Thanks for the recommendation.

        I also started using a pair of Emission Labs 300BLX in my ANK Kit1, the sound is just superb to my ears, nice extended highs, with a tight deep bass. I like them better than the SERPS, which I thought are quite good…I will be staying with these for a while.

        My speakers are Lowther PM2A in a Mauhorn X11 box, and I use an Esoteric SA60, and Thorens 160 Super with a Lin LVX arm.

        • Hi Stuart,

          The Duelund DCA20GA interconnects are really nice, for sure!

          I haven’t heard the Emission Labs tubes, but they have a good reputation.

          Sounds like you’ve got a really nice set of kit put together!

          Happy listening,


  7. Hi Jeff,

    I’ve purchased a quad of the Sophia Electric EL34’s and i’m waiting for them to arrive. I have a pair of ANK EL34 Monoblocks and i’m running g them with Gold Lion KT77’s. They sound superb at the moment. These have been the best sounding new stock tube i’ve tried, so i’m looking forward to hearing what the Sophia’s will add to the system.

    • Hi Campo,

      Let me know what you think of the SE EL34-ST’s compared to your GL KT77’s.

      I’ve got a quad of the GLKT88’s, but I’ve not yet heard the KT77’s.

      Kind regards,


  8. Hi Jeff;
    Which Aqua 274b do I need for the MC30‘s?
    Mesh plate or rigid.
    Best wishes

    • Hi Claus,

      The Aqua 274B rectifier only comes in one version, the one I reviewed here.

      It’s a really nice rectifier, I think you’ll like it!

      Kind regards,


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