Mike Sweeney
Well-Known Member
So I'm rebuilding my 2226B and if you have been following along, my last task was to rebuild the Tone board ( PE01).. it's pretty simple with a fwe non-polarized caps, a few electrolyics and a few film caps. Lets look at RE03 and CE01 and CE02.. normal big brown film cap.. .22uf 50v. Nothing special about the cap other than the RE03 handles the volume control. It's a double pot so there is ganged pots for R/L channel.
I "thought" I wanted to replace CE01/2 since I was in there mucking around but I didnt have any .22 films.. so I went on Amazon and picked up a kit of assorted films at 100V.. figured it would be nice to have some at the ready.. and this was a non-critical circuit.. hell, it's the volume
I should have listened to my gut about using cheap-ass imported parts. I put in the new caps.. and a couple of electrolytic caps that I could not reach with the board in place. Put it all back together and powered it up. Got a hum with volume down.. have leakage from the left channel with volume all the way down.. but the right seems to work.. when I turn up the volume.. left seems to come up but is fuzzy.. So I swear a bit.. turn it off.. look at the schematics and I'm thinking the only changes that could do this are those two new films. I pull them out.. put the old parts back in and life is good.. Volume is solid.. no hum.
So
These cheap-ass caps test good on my ESR tester but I'm guessing they are leaking like a sieve.. at least one is. The other might be OK.. but these were brand new caps. So I just wasted 15 bucks on a bunch of dubious quality caps
Lesson learned.. only buy stock from Digikey ( my normal goto) or other major supplier. I think now I'll just leave the OEM caps there..being film, they ought to last for a long time.. unlike the electrolytics
I "thought" I wanted to replace CE01/2 since I was in there mucking around but I didnt have any .22 films.. so I went on Amazon and picked up a kit of assorted films at 100V.. figured it would be nice to have some at the ready.. and this was a non-critical circuit.. hell, it's the volume
I should have listened to my gut about using cheap-ass imported parts. I put in the new caps.. and a couple of electrolytic caps that I could not reach with the board in place. Put it all back together and powered it up. Got a hum with volume down.. have leakage from the left channel with volume all the way down.. but the right seems to work.. when I turn up the volume.. left seems to come up but is fuzzy.. So I swear a bit.. turn it off.. look at the schematics and I'm thinking the only changes that could do this are those two new films. I pull them out.. put the old parts back in and life is good.. Volume is solid.. no hum.So
These cheap-ass caps test good on my ESR tester but I'm guessing they are leaking like a sieve.. at least one is. The other might be OK.. but these were brand new caps. So I just wasted 15 bucks on a bunch of dubious quality caps
Lesson learned.. only buy stock from Digikey ( my normal goto) or other major supplier. I think now I'll just leave the OEM caps there..being film, they ought to last for a long time.. unlike the electrolytics 
