This is a rebuild onto a custom made steel chassis in a wooden case.


I built a single ended valve amplifier (one power valve with single winding on output transformer) at some point in the mid-late 90s. I didn't use a mains transformer and kept blowing rectifier valves with too much current. Never the less I got it to work, a nice amp with approx 4w of power using an ECC82 and EL84.

At the time I was given a circuit for the amp I built and a push pull amp, I never did build the PP amp until now (20 or so years later)


This uses a mains transformer with 190v secondary, giving me 260 or so volts after rectification and smoothing.

I have done some modifications to the circuit, the first being an extra resistor on the phase inverter to bias it from ground and balance the phase, which it now is, and a central grounding point.

The hum has pretty much gone, with great sound quality

I'm using an ECC82 valve, and this is designed more for a line level signal with the preamp gain. You can connect a guitar direct but you don't get the volume. Swapping to an ECC83 with a higher gain and using the spare triode to make an extra preamp stage would work nicely.

Plans are now to build a bigger amp with 2 pairs of EL84s in parallel.