mshilarious
Banned
Anybody ever screw with their Portastudio? I've got my 424mkII open in front of me, looking the the mixer section. I'll probably take a pass on the tape section, although there is one kickass IC that is 64 pin thru-hole! It's probably bigger than a modern CPU! I would guess it controls the screen display, but anyway . . .
Back to the mixer section. I was thinking about patching in phantom power to inputs 1-2 using the V+ rail, I haven't measured it yet but looking at the caps it's probably 12 or 15V. I figure I'll remove the existing load resistors and run the phantom across 3.3K resistors and see how that goes. It should run electrets OK. I'm not going to bother with a case mod, so it will be unswitched.
The rest of the board looks generally OK . . . I might swap a few electros, but I ain't recapping the whole thing. The opamps are all NJM4565, in a 8-SIP package . . . not much to be done with that package anymore, although I see Mouser has 5532s in 8-SIP . . .
So far I have cleaned the faders
Back to the mixer section. I was thinking about patching in phantom power to inputs 1-2 using the V+ rail, I haven't measured it yet but looking at the caps it's probably 12 or 15V. I figure I'll remove the existing load resistors and run the phantom across 3.3K resistors and see how that goes. It should run electrets OK. I'm not going to bother with a case mod, so it will be unswitched.
The rest of the board looks generally OK . . . I might swap a few electros, but I ain't recapping the whole thing. The opamps are all NJM4565, in a 8-SIP package . . . not much to be done with that package anymore, although I see Mouser has 5532s in 8-SIP . . .
So far I have cleaned the faders