freestompboxes.org

I did this for my personal use/self education as a quick reference. Perhaps some of you will find it useful too

Taken, and reedited to info in a pill from Ken Fisher Trainwreck Pages document - related tread here

Few mods are possible, like pot in place of R5/R6 to control gain stage.... gain As was done in Hiwatt DRxxx Lead, but I'm still learning so should shut. I would love to get an input from knowledge members on the other hand

Looks pretty comprehensive to me, I've seen some amp schematics where there's a 1M resistor in series with a cap connected in series with it from the Plate/Anode to the Grid on one of the gain-stages, most likely a Negative-Feedback path.....

DrNomis wrote:Looks pretty comprehensive to me, I've seen some amp schematics where there's a 1M resistor in series with a cap connected in series with it from the Plate/Anode to the Grid on one of the gain-stages, most likely a Negative-Feedback path.....

I've seen it too, Cornford Harlequin is the one written into my memory who had bypass cap on plate resistor

There's one gain-stage with the negative-feedback path in the pre-amp schematic for my Marshall MA 100C amp, it's right before the signal goes to the tonestack for the Overdrive channel, the cap value is 100nF (.1uF) and the resistor value is 100M,grid resistor to ground is 1M, Plate resistor is 100k, Cathode resistor is 820 Ohms, I'm pretty sure the Peavey 5150 preamp schematic has a gain-stage with the negative-feedback path too, probably same values......