Thanks. I figured that out after awhile. I replaced the carbon comps with larger metal films. Also replaced the orange drop caps with 600 volt panasonics and all the ceramic disk caps. I also changed the input pad R104 with a 1.5M and C6 with a 180pf like later amps. I probably did more than I...
I'll be doing that mod to my SOB after I order the 250K pot if I don't find one in my leftovers. Another post said they used an audio taper so I'll go with that.
I'll let you know how it turns out.
Thanks
Ger
I measured the bias current with a Eurotube bias probe. Tube 6 EL84 reads 30.22 milliamps. Tube 7 EL84 reads 33.82 milliamps at 400 plate volts.
Those are both way too high. That is Class A territory.
70% dissipation for a fixed bias EL84 with a 400v plate voltage is 23.333. I need to knock the...
My reverb quit working so I pulled the chassis and isolated the reverb tranny as the problem. Ordered one from Mesa.
I changed the 3 filter caps, 470uF16v and 270uF63v caps some years ago. I also added Don's lead drive mod and moved the reverb to the back.
The amp works great but I don't use it...
Digikey part# RPC5504-ND
MFG Essentra Components
Looks like an identical replacement for my studio 22+ standoff.
Not sure about the shield supports. I didn't look for them.