The Amp Garage

Sorry Reel I mispoke. What I meant to say is "If I AM getting this interference without an input cord plugged in."

Not sure how large a hole in the chassis has to be to allow radio waves in, but if any of the holes you've described as 'hacked a bunch of holes in the chassis' are larger than, perhaps 1/4", you might consider covering them up with metal plates that are well-grounded to the chassis. Certainly, if ...

If the interference is getting into the grid of V1 then try a 15pf-30pf cap from the input to ground. It will shunt radio freq to ground. Also, make sure the 1 meg resistor on the input is connected right. If I'm not getting this interference without an input cord plugged in, or even with the wires...

Thanks! I'll give it a try. In theory though, I still don't quite understand how this will make a difference. On say a TW Express that does not have an input grid resistor this makes sense, but since the superlead has two 68K grid resistors and when you plug into one input the value is approximately...

As this circuit uses both the input grids on V1 (pins 2 & 7), should I add a 33K resistor to both grids or just one?

That's what I would assume as well, but as I've replaced all 6 power supply caps and both bias supply caps with brand new ones, I wouldn't think that would be the issue.

Hey Guys, I recently scored a 74 super lead on the cheap and have done my best to convert the circuit back to its original specs. Someone had hacked a bunch of holes in the chassis and added a relay switching system and a bunch of other crap... Anyway, other than adding a PPIMV and a half power swit...