I would like to mod my preamp on my 2204 MK2 master circuit (that I built into my Traynor) to switch between an original plexi(ish) type preamp and current MK2 master in there now. I don't need both triodes on the plexi, just the bright and common cathode. The challenges are the voltage dividers and the cold clipper on v2 plus others so I know it can't be 100%. I'm just looking for an approximation of that crackle. Can anyone suggest a schematic of another amp that does something similar ?