Memorymoog service info...!?

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1

Hi Folks,

My recently acquired Memorymoog does have one very slight issue which I would have sorted by now, but I cannot seem to find the relevant info in the service manual..! The issue is Osc 3 on voice 5 is louder than all the rest. The service manual has extensive notes on tuning calibration, some mention of VCF calibration… but the only reference to the VCA is one for setting the VCA ‘balance’ and eliminating ‘thump’…!?

Does anyone know where I might find instructions for setting individual voice levels please…?

Cheers,
Tom

2

There are trimpots for balancing levels between voices, but there is no calibration to balance oscillator levels in a voice.

You have a component malfunction someplace in the OSC3 circuit.

3

The service manual pdf. states - on page 26 - under the heading: “THE AUDIO OUTPUT”

“Notice that VOICES B through F have individual trim pots to match the output VOLUME of each VOICE CARD to the A VOICE…”

So that does indeed seem to be the case, however looking at the Osc board schematic - Osc 3 on each board has a VCA “offset” trimmer. Would anyone have any experience with this trimmer. Does it set the level for Oscillator 3…?

Cheers,
Tom

4

R106 VCA Offset doesn’t set the audio level, it nulls out the DC offset when OSC3 is used as a modulation source. The 3360 above that carries the audio signal of OSC3.

5

Try swapping the CEM3360. If you need another one I have them in stock.

6

Check U9 and U10. Swap from another voice card.