Hi guys
(rebuild)The amp parts were kept to all original values as I'm keeping it as original as possible (just as a sentimental amp)
I haven't finished with its preamp (Varislope Stereo) yet, just waiting for some electrolytics.
Anyhow I ran the amp with another tube preamp I built a while back and it sounds great, there was
a small issues that I had, I connected the preamp to the amp with a set of everyday RCA cables and I was getting
lots of noise coming out of the speakers, I then changed them with a better quality set and that dropped the noise by 80% (but still have an issue).
The amp had a mod done, when? I don't know, but they looks old at least 30 or so years old. Anyhow the mod is the addition of
a 250k stereo pot from the RCA inputs with a 220k resistor on the wipe to pins 2 and 7 of V1 the 12ax7 and also the R2L/R
has been changed to a 220k resistor, the schematics show a 22k resistor.
Can anyone shed some light on this?
cheers