Scott Gerus Amp 5 -- Tube Regulated 2A3

Back in 2009 I saw a set of 2A3 monoblocks on eBay that rang all my bells. They were hobbyist-built one-of-a-kind amplifiers, with a mirrored layout, nice wood work, beautiful aesthetics…they were everything I wanted at the time, but were out of my price range by a good margin and I watched them sell to someone else. I kept note of the builder, Scott Gerus, and over the years saw a few more of his beautiful amplifiers sell on eBay. But never at a time when I could afford to bid, and eventually things slowed down and these amps went to the back of my mind. But that first monoblock 2A3 was never quite forgotten.

Fast forward to the Fall of 2018 when one of the most amazing of the one-off Gerus amplifiers came up on the used market, and from its original owner. I grabbed it! And here we have the prize, a Scott Gerus one of a kind 2A3 single ended amplifier with a tube regulated power supply. Based on the Western Electric 91a circuit, this is an amplifier that really defines the art of the scratch-built high-end audio world. Obviously inspired by the Yamamoto design, this is a melding of both woodworking and electrical engineering skill, and is simply stunning in both appearance and fidelity. Scott built this amplifier with precision, care and love and it shows everywhere.

Having owned a few hobbyist built amps before, from good, to bad, to ugly, I can say that this is at home in the company of ANYTHING I’ve owned to the present. This is a large and imposing amplifier at 24 inches wide, but its organic shape and form make it seem to blend into the background in a way the Art Audio, which is smaller, can never do. Its imposing sweeping wooden top plate sets this apart from anything I’ve seen so far. With the larger tube sockets routed and drilled in the same fashion as Yamamoto, the look is clean and understated elegance. Hammer tone copper paint blends the transformer cover into the woodworking nicely and looks better than that sounds on paper. All in all, this is an ambitious and wildly successful project.

So, how does it sound? Like all of the WE91a circuits I’ve heard so far, this amp has a certain signature that feels center-focused and has plenty of weight and density. Unlike some others, this version of the 91a also has a very nice top end; it has deep presence but is still open and airy, and it images very well. That's a lot. Tonality is spot on and this is a very enjoyable amplifier to listen to for extended sessions. Its very clear sounding, but not fatiguing. Voices are in the room and palpable. Overall, this amp is performing as well as the best I’ve had. This is actually the first 2A3 amplifier I’ve owned so it's a learning experience, and I feel like maybe I should have paid attention a long time ago. Of the power tubes I’ve tried, I like the 2A3-40 in this amp better than any of the vintage or modern tubes (I do not have single plates or EML), it just takes the sound to a bigger and bolder level somehow, even though I understand that it is not making more power than a normal 2A3. Based on that, if you have a 2A3 amplifier and haven’t tried the 2A3-40 it might be a good Christmas present to yourself! So equipped, this is certainly one of the coolest amplifiers I’ve owned, both in builder vision and pure fidelity.

Scott Gerus is making new amplifers and can be reached at his website 300bamps.

This has got to be one of the best looking amplifiers I’ve ever seen. I love the flow of the wood grain in the thick top plate.

6J7G provide the preamp power. Cool mesh plate top cap tubes and a good alternative to the much more costly Western Electric 310a.

This amplifier features a tube regulated power supply. Here we have a 6SA7, a 6SL7 and a 5U4 rectifier. Behind the amp under the transformer cover is an OB3 regulator tube.

Two switchable speaker outputs is a very interesting feature of this amplifier and one I hope to take advantage of in A/B speaker testing.

This seems to be a good match with the Minimax Preamplifer.

Here with JJ 2A3-40 output tubes. These are the best sounding tubes I've used in the amp so far.


Tube regulated amps often feature these cool glowing regulator tubes, in this case an OA3.