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Vintage Synth Repair

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Re: [vintagesynthrepair] Micromoog LFO

2013-05-23 by Mike Kearney

Hi Aron,

Given your symptoms, page 5-8 of the service manual suggests the culprit is IC801, a 1458 dual op amp chip. At least that's how I read it.

If your troubleshooting confirms this, I would suggest removing the chip, installing a socket and a replacement 1458. A thermostatically controlled soldering iron makes the job easy. Be sure to use flux remover to clean in between the solder pads when you're done.



On 5/22/2013 8:59 PM, stompboxaron wrote:

Got my Micromoog working (it took 3 years!).

Now the LFO doesn't work.

Bend, Noise works. Everything else Square Wave, Triangle, S&H AUTO etc.... only produce a different in pitch. The RATE knob has no effect.. The routing switches work.

For the people that have worked on the Micromoog, does this sound like a common problem?

Thanks in advance.

Aron


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