More about the 801A SE Tube Amp Magic of Thomas Mayer  

December 2010



Here is an update on my quest for finding "my ultimate amplifier" and my experience with the Thomas Mayer 801A SE stereo amp (I wrote about this amplifier the first time a little over a year ago).

It took me about a week of listening to this magical amp back then (the version with the universal power supply and the Lundahl interstage transformers) to make my decision that this is the amplifier to go for. So, I purchased it from Thomas. Although the speakers I used back then (and currently use) are not the optimum match for a 3.5 watt SE tube amp (their efficiency is around 92 dB), the musical performance of the amp is superb.

Regarding the speakers, I first used the Haigner modified Altec Valencias, and after the Vienna Vibes festival (as the Valencias had been sold) the superb Haigner Tau 3-way monitor system, both on loan from David Haigner.


Here you see the amplifier in all its glory...


None of my other tube amps - 2A3 Moondogs, WE91 300B monos / top level kit version from DIY Hifi Supply or my pimped Dynaco ST70 (Welborne Labs upgrade kit) - come even close to what this transformer coupled tungsten filament 801A is capable of.

OK, especially the Dynaco and also the WE91 amps deliver more powerful bass with the above-mentioned speakers. However, the quality of bass reproduction is not better overall, and the musical flow and mids and treble resolution of this Thomas Mayer creation are nothing but awesome. You have to listen to percussion and vibraharp playing through this amp, for example, to understand how many shadings and tonal layers these instruments can have (track "In Memoriam" from the wonderful MJQ Album, "More from the Last Concert", Atlantic SD-8806). 

The Moondogs, although great in this department too, are somewhat coarse and noisy in comparison, mainly due to the much more sophisticated power supply design of Thomas Mayer.

To be fair, there is quite a price difference between my other amps and the 801 amp due to the different amplifier philosophy of Thomas Mayer and all the iron used to get an 801A tube to run so smoothly and cleanly in pure class A.

In short, the 801A SE amp is superb, and listening to it is a musical adventure. The only caveat I have encountered is that with the speakers currently used, I got the amp into clipping on certain kinds of music, for example, rock music played loud. But I know with the Haigner Gamma horns and their efficiency of +98 dB, there are enough reserves for all kinds of music and listening moods.

In November 2009, I had the chance to listen to a slightly-modified 801 SE stereo amp with the highly regarded NC-20F interstage transformers manufactured by Tango. The power supply was the same universal type I use. The difference in a familiar system around the Haigner Tau was minor, but seemed further refined with more resolution and more color in the mids and treble section.

Thomas told me at this occasion that there is the possibility for a power-supply upgrade by using a new and definitely better power transformer together with four TV-damper 6AX4 tubes as rectifiers. Giving up the universal ps type (which also can be used with the Mayer SE stereo 300B amp) would simplify the layout and spare some switches.

So, in October 2010 I decided to go for my final version of the 801A SE amp. I upgraded to the Tango interstage version and the new power supply. My former 801A amps went back to Thomas and a bit later to Berlin, to an audio enthusiast and friend of ours, who has also gotten hooked on Mayer tube-amp magic.


New improved power supply

801A SE stereo amp with Tango NC-20 interstage transformers

And how does the new amp work in my system and with the Haigner Tau, you might ask?  

Well, after some weeks of listening I can say that this 801A-version is definitely magical too and a slight but worthwhile improvement to the version I had before. The new power supply is responsible for most of the difference, I would guess. The amp feels more powerful and more dynamic connected to the Tau. By now, I couldn't drive this version of the amp into clipping, although I played really loud ;-).  By the way, this not only speaks for the improved power supply Thomas Mayer developed, but also for the loudspeaker concept of David Haigner, who especially designs his speakers with low powered SE tube amp designs in mind.

Musically, my new 801A-amp is superb, with improved resolution and a tad sweeter and more engaging sound. The latter is what you get for the roughly EUR 700 price difference between Lundahl and Tango interstage transformers.

I haven't had the possibility to listen to one of the famous Kondo, Komuro, Shindo or JC Morrison triode amp creations by now, even though I'd love to. However, I'm convinced that the Thomas Mayer 801A SE triode amp is one of a rare species of amplifier designs, which totally connects you to the music and the artists performing their music. And isn't that what our beloved hobby is about? For me it definitely is :-)

In a nutshell, this amp is honestly that good and will be a wonderful match for the Gammas. Soon, I will know for sure ...

Musically yours,


PS: For intermediate and advanced DIYers, I saved the best for last: Thomas Mayer is also offering a kit version of this 801A SE two chassis stereo amp. This saves some cash for those who have the skills to finalize a more complex amplifier project (or know someone with these skills). It is important to note though, that due to the high voltages the 801A runs in, only experienced DIY-builders should get involved with such a project.

If you are interested you can contact Thomas directly via email under thomas'at' for more info.


The Audio Eagle 2005-2011• All Rights Reserved • Disclaimer