Hi there all.
I’m new to this forum and hope this hasn’t been discussed
In a previous thread.
I have a prodigy serial #1313 and my issue is that
Oscillator 2 only makes a clicking sound
The rails are reading right and I can alter the speed of the
Pulses somewhat with the interval knob
Any help would be appreciated
Oh I should mention that the unit was modded
By I assume someone @ Moog
Thanks again
Hi and welcome Kevan.
Probably the linear voltage to exponential current converter for oscillator #2 (U3) that has failed. It is an LM3046.
I would start there. If that doesn’t fix the problem, then it could be the LM353 dual op amp (U4).
After replacing either of those chips, you’ll need to recalibrate the Prodigy.
Did these problems suddenly occur to an otherwise previously fine instrument?
Was it recently purchased or shipped?
Components do go bad all time, but before replacing them I think it’s helpful to know if you just acquired it or if it suddenly just broke.
hi again and thanks for responding
i aquired this recently and initially it did nothing.
cracked it open to check the board out and suddenly…sound
oscillator 1 was emitting a steadily rising tone, waveform selector worked modulation works filter worked
i had to eek the attack up a bit past 10 msec to make this tone inaudible which im fine with (though im not sure thats ok)
osc 2 however click click click.
i know in older stuff like this ic s can and most likely will go bad if theyre not already dead
also the filter went on it. no effect no self oscillation external audio is unaffected by it.
swapped out the socketed lm 3046s both of em for ECG 912s no change
ill try the op amps next.
as for the filter i (foolishly) suspected the CA3048 ic s had gone bad replacing them and now the whole synth is muffled sounding with no sharpness in the saw or square. on top of that ive got white noise whenever a key is pressed and the synth is really not nearly as loud as it was.
nor did it fix the filter.and osc two is the same clicking
im not gonna let this thing die on me.
Well I now have both osc 1&2 so horray for that
Swapping out U4 did the trick
However overall output is very low and
Soaked in a white noise
Possibly another op amp?
Should I just swap all of them out?
Can’t wait to use this beast with my minikorg 700
High note priority for the left hand
Low note priority for the right one.
Mono Madness