3 PCM 41 units in for repairs. These are some of my favourite delays, many fond memories playing with these in feedback.
The first unit had a blow cap in the -ve power supply rail. Clearly someone had previously replaced the power supply filter caps...I will clean ip that repair a bit. I don't like to the old silicon on the pcb...and the would prefer a cleaner solder job....
and yes the blown cap is pretty obvious ;) I also don't like the regulator sockets used.
It also had a broken 4 pin pot... yes four pins...the fourth pin being the center tap of the rheostat.
Interesting design, very impressive actually....
Comments
paulears wrote: Was the socketed regulator original? I’ve not se
paulears wrote: Was the socketed regulator original? I’ve not seen that before, but as many were run so near the limit, it’s quite a good idea as retested replacements messes up the board doesn’t it.
One sheared input pot and one open circuit feedback pot. Great d
One sheared input pot and one open circuit feedback pot. Great design, cheap pots ;) Dr. Lee had some very advanced thinking for the time in the design. Very interesting origins of the company too. Worth a bit of read....
Was the socketed regulator original? I’ve not seen that before,