Push-Pull 6V6 Amplifier
This amplifier was a gift to my father-in-law for Christmas a few years back. It is a distributed load push-pull output topology called “Ultra-Linear” back in the day. That is driven by a direct-coupled split-load phase inverter, preceded by a single gain stage, all using the common 12AU7. With this circuit no preamplifier would be needed, as my father-in-law has a turntable with line-level output.
This schematic represents possibly the best bang-for-your-buck project I’ve done. Although parts were purchased new to ensure a “shiny & new” appearance, they were not expensive. This circuit contains all of the features that make tube amps what they are while minimizing inherent drawbacks.
Evil Science Audio 
Hello Bill,
I’m getting set to embark on my first amp build and would like to attempt what you’ve done here with the 6V6. Is a full version of the schematic available, either free or for purchase?
Thanks!
John
Hi John,
The schematic shown is the full electronic schematic. Of course it shows only one of two identical audio channels. I don’t do mechanical drawings of my projects because they are each unique. The full size view of the posted schematic can be had by clicking on it, if that helps.
Have fun with the hobby!
I have built a mono block version of the 6V6 amp. I really like it and plan to build a stereo version soon. I have a question. On your picture of your build of this amp, I see control knobs located near each channel of the amp. I would like to know what the controls are used for. I suspect they are for DC balance. I would really like for you to share the hook up and component values. Thanks for all your design endeavors.
Don Ferguson
The added controls are a source select and a volume control. There are four sets of inputs on the back. This was an attempt to make the amp “integrated”, The amplifier really does not have enough gain to be used without a preamplifier so I can’t recommend these changes.