I’ve got a vintage Deluxe Electric Mistress Flanger (from 1978) that isn’t working. In the flanger mode, the rate doesn’t seem to be working. It has some output for a minute, then fades out. 15V rail seems good. I see clocks out of the LM311. I also see output on pin6 and 12 of the SAD1024 chip. So I think the SAD is good. But I don’t see the low frequency on pin 8 of the LM324. Any thoughts on what to check?
Thanks,
-E
I should have mentioned. I verified all the connectivity in the RATE portion of the circuit. There were some issues (broken traces) with one of the pots and I added a jumper wire to connect that leg to the proper component. I saw some listings of people checking voltages on all of the ICs. Is there a reference voltage list? I’m wondering if the LM324 is bad.
Another observation on the broken Deluxe Elec. Mistress. When I put a sine wave in, I see it on the first pin of the input decoupling cap (27nf cap in the schematic link below). On the other side of the input decoupling cap, I see the sine wave with a 15 volt DC offset. Is this normal? Or is this a clue to a problem? Any suggestions?
Also, I replaced the LM324 and the two 33uF caps associated with the Rate, but I still don’t see the rate moving on Pin 8 of the LM324. http://www.metzgerralf.de/elekt/stomp/mistress/images/deluxe-electric-mistress-v2-schematic.gif
