DIY/T2 Electrostatic Amp Thread - General

[justin w.]

12-15Vrms max output from the XLR isn't uncommon now

Highest ive seen is 18

 

[mulveling]

12-15Vrms max output from the XLR isn't uncommon now

Highest ive seen is 18

That is bonkers - is there any rationale behind this kind of source design? The risk aspect alone is worrying - e.g. if someone messes up a preamp HT bypass connection, and inadvertently sends full 15 Volt line signal to their power amp, they could easily blow their speakers.

 

[ufospls2]

Hi Guys,

Today’s review is actually one I wrote quite a long time ago, but am posting now. After owning the T2 for a year I decided to sell it and allocate the funds elsewhere in my setup. I really enjoyed my year with it, and I hope the review helps some people who are looking at top-end electrostatic amp solutions.

The Stax SRM-T2 is a legendary amp in the niche within a niche of electrostatic headphone land. Produced in the early 90s as the companion amp to the original Stax Omega headphones, it was big, ran hot, and was very expensive. Ultimately Stax discontinued its production, but it was brought back to life, in a way, through Kevin Gilmore when the DIY T2 design was released over a decade ago. The DIYT2 is a complicated labour-intensive design, and was over $ 10,000 USD when commissioned from the few builders who took on building them for others. Quite a few of the parts used in the original DIYT2 are now EOL and unavailable readily. However, Kerry Gerontianos, now of Eksonic Audio, worked on his own modification of the design using more readily available parts. Over the course of a period of years, this slowly morphed into the version currently available, and the creation of Eksonic Audio. Eksonic currently offers two amplifiers, their version of the T2, and the aeras, a smaller amp which aims to try and capture the sonics of the T2 in a smaller and slightly more affordable package. I haven’t heard the aeras, but it certainly seems promising in its own right.

Over the span of the availability of the DIYT2, especially in the earlier years when there were very few of them in existence, it gained a sort of mythical reputation as an amp that would take any electrostatic headphone and turn it into the best headphone on the market. I think this reputation came about simply through a few very vocal owners in the early days, and also due to the low number of models that had been built. When I originally decided to venture into electrostatic headphones, I wanted to give them the best shot I could, and be fair in my assessment. I remember reading a lot of posters on the headphone forums say something negative about a “x” electrostatic headphone, and their opinion being discarded by the electrostatic niche simply because “they hadn’t heard them on a T2.” Since then, I’ve owned the HeadAmp BHSE, the KGSSHV Carbon (built by headinclouds,) the Mjolnir Carbon CC, The Kevin Gilmore Grounded Grid (KGGG,) The Eksonic T2, and have heard multiple other amps like the Shangri-La JR amp from Hifiman, and few different Stax branded amps. I feel over the course of time, I’ve gotten a fairly good idea about the various amplifiers, and where the T2 stands with regards to them. Overall, is the T2 a mythical giant that will turn any electrostatic headphone into a different animal, the best headphone on the market? No. Is the T2 the best electrostatic amp I’ve personally heard thus far? Yes. So as with most things, the truth is somewhere in the middle.

So with all that preamble out of the way, how does the Eksonic T2 sound?

The low end of the T2 is one of its standout areas. In terms of bass level, I would describe it as being slightly more than neutral, but not bass-heavy. Where it excels is in the technical performance of the low end. The bass is very fast, detailed, and the amp shows extremely very good control over the drivers, better than any other amp I’ve heard. It didn’t seem to matter what headphone or music I threw at it, it was utterly unflappable in its low-end performance and really did bring out the best in the headphone I was using with it.

The midrange of the T2 is very slightly warm in the low mid-range and neutral through the upper mids. It isn’t overly warm as some amps can be, but it is definitely warmer than amps like the KGSSHV Carbon. Its a very subtle but noticeable harmonic richness that adds a nice touch to headphones that can be brighter or colder sounding. The SR009 worked very well with this as well as the Shangri-la from Hifiman. The overall technical performance through the mids is very similar to the rest of the amps performance, in that it is highly detailed and fast.

I perceived the treble performance of the T2 in terms of level as being neutral through the lower treble and slightly more than neutral in the upper treble, giving the overall sound signature a nice sense of space and air. The treble isn’t bright or sharp in any way, and can be slightly tweaked with tube rolling. That being said I didn’t find that the small amount of tube rolling I tried made massive differences to the sound signature, but can slightly change things depending on the tubes being used. Similar to the bass and the mids, the technical performance of the treble was quick, detailed, and very controlled.

The technical performance of the T2 is really where it shines most. It is an incredibly detailed, fast, and unflappable amplifier. It didn’t seem to matter what headphones I threw at it, it remained the same in terms of its sound signature. With some electrostatic amps at the lower end, they can run out of juice or current and start to lose control over the drivers and distort or just sound sharp and overly bright. I never experienced this with the T2. In terms of detail, it was the most detailed electrostatic amp I’ve heard, but I would also mention that when you are at this level, the differences become small. So whilst it is the best and most technically capable amplifier I have heard for electrostatic headphones, the differences are not as big as they may be coming across as, in comparison to a KGSSHV Carbon, or similar.

The build quality of the T2 from Eksonic is as good as I have come across. My amp was finished in the mirror black finish (which is no longer available) but it just oozed quality. Everything about it was awesome. It was sturdy, well-built, and looked superb (to me.) It came very well packaged to keep it safe, and I had no complaints about the T2 with regards to its build quality.

Compared to the HeadAmp BHSE, the T2 is actually very similar in some ways, but slightly better in others. I found the T2 to be slightly warmer, but also slightly more detailed and technically capable. It also seemed to exhibit slightly better control over the drivers of the headphones being used.

Compared to the KGSSHV Carbon, and the Mjolnir Carbon CC the T2 was again slightly warmer, and slightly more detailed. The KGSSHV Carbon and Carbon CC seemed more similar to the BHSE than the T2 in terms of sound signature. The T2 was slightly more forgiving whilst also being slightly more detailed.

Compared to the KGGG, the T2 was actually more similar in terms of tonal balance. However, I did find the T2 to have more drive to it, and again felt like there was more detail and control over the drivers.

Overall, the Eksonic T2 is a heck of an amplifier. I don’t think the T2 lives up to the mythical reputation it has gained over the years. It doesn’t transform any and every electrostatic headphone into the best thing on the market and into a completely different headphone. With that being said, it is the best-performing electrostatic amp I have personally had the opportunity to try. As with most things, the truth is somewhere in the middle. It is a slightly warm, harmonically rich amp, that has gobs of detail. It never missed a trick and was utterly unfazed regardless of which headphone I threw at it, from easy to drive to something like the SR007 or Audeze CRBN (both very difficult to drive.) I’m really glad I took the chance on it and was able to hear for myself vs. just reading other people’s opinions about it. I think Kerry over at Eksonic did a really super job with his version of the amp, and it’s something I’d highly recommend trying if you are interested, and can afford the outlay. If you can’t, or simply don’t want to spend 5 figures on an electrostatic amplifier, don’t worry. The other designs that are available are still awesome, and you aren’t missing out on that much! Still, the T2 is the best electrostatic amp that I’ve personally heard, and I’d recommend it highly.

 

[13candles]

Finally.....
This might well be the only written review of Kerry's T2 or any DIY-T2 out in the wild.

Thank you Paul for taking the time to express your honest opinion and informative thoughts which I thoroughly enjoyed reading!
Cheers mate!

 

[KDS315]

There are lots of "slightly"s in that T2 review, so based on "diminishing returns" it seems that those 5 figures spent makes only sense for very critical listeners, right?

 

[Aspirant Audiophile]

Finally.....
This might well be the only written review of Kerry's T2 or any DIY-T2 out in the wild.

Thank you Paul for taking the time to express your honest opinion and informative thoughts which I thoroughly enjoyed reading!
Cheers mate!

@Schelp san did a series of great write-ups a year or two ago, but this one indeed is an excellent reflection. I still have moments wishing I had a T2...but reviews like this help me spend a lot more time being happy with what I have