How to calibrate scale on 901B

System 55 • System 35 • Model 15
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johny_gtr
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Joined: Sat Nov 14, 2020 4:16 pm

How to calibrate scale on 901B

Post by johny_gtr » Sat Nov 14, 2020 4:31 pm

I'm in interesting situation

901A+901B+901B tracking is well for 5 octaves
third 901B is out of scale (about semitone difference in 2 octaves). Are there any internal trimmers to adjust scale parameter for 901B?

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analogmonster
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Location: Germany
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Re: How to calibrate scale on 901B

Post by analogmonster » Sun Nov 29, 2020 11:48 am

No scale in the meaning of ocatve spreading in the 901B. Did you follow the 901B adjustment procedure of the service manual? When I cloned the 901A and B I faced side effects of the VERNIER control meaning changing the VERNIER also changed the scale a little bit, so perhaps you could try to track the oscillators with exactly the same VERNIER positions using the tracking trimmer instead of following the service manual adjustment procedure.

See also http://www.analog-monster.de/mmt901_en.html

Best

Carsten

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