I've always loved the sound of vintage Acoustic 370 amps so I decided to build the power amp section of one to be used as a booster/OD and I couldn't be happier with the result. I used the factory schematic and cloned it with the exception of instead of using power output transistors, I used ones that would run at line level. It is an exact clone of the actual amp's circuit, right down to using the same NOS transistors (12 of them!). One of the most unique things about it is that it has a Jfet AGC (Auto Gain Control) circuit that compresses the signal if it surpasses a specified level and prevents the output transistors from distortion. In my version, it added a trimmer so that I could adjust the threshold to clip the output into overdrive so it sounds like you're running a 370 into dirt territory..
It is actually very transparent and has a ton of clean boost available yet is very low noise. It contains an internal charge pump so part of the circuit is running on 18V and the input driver fet chip is running at +18/-18V (=36volts!) off of a standard 9V center negative power supply. It draws 40ma @ 9 volts. DO NOT use a power supply other than a decent quality one like a one spot, a Dunlop or a Boss that exceeds 9 volts.
It also has a relayed true bypass with a clickless soft stomp switch which I've come to prefer over the cheaper click type stomps since relayed ones are quieter and more reliable. The enlsure is a 125B with the in & out as well as the DC jack are all top mounted.
Due to the complexity and the rarity of the components in this build, this one is the ONLY one available and I will not be making any more of them for sale. I've built a total of 6 of these and I'm keeping one for myself so, after this one is solld there will be only 5 of them out in the 'wild'.
$400 + actual shipping
SOLD
