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Subject: Re: [korgpolyex] External Audio in Mod.

From: billmeirelles@...
Date: 2011-07-17

I'm not sure how I did it, I found the descripton at the forum but
can't remember where, anyways I believe I took out the negative
leg of the cap prior to pin 19, connect the negative leg to the center
of a 2 pos switch, at one side of the switch you connect your external
audio source and at the other side you reconnect it to the board so
you can choose between external in and noise. The thing is, the EG
used to modulate this VCA input is the same used to to modulate
the VFC so you and up with a one EG only synth if not using the
internal oscilators. Check this page for a good disciption the
NJM2609 chip http://tnt23.livejournal.com/789722.html

Cheers,
Bill Meirelles

Em 17/07/2011 12:22, 7yash < josh.nursing@... > escreveu:

Hi all,

Considering that the Osc section of the Poly-800 uses an additive form synthesis with Square waves, I thought that the next nice mod for mine would be to build an External Audio Input module.

This would help beef up the Osc section with either additional Osc modules or help treat external audio through the excellent NJM2609 VCF.

Looking at the schematics, I think I should use Pin 19. It looks like I could also use Pins 20 & 21. I though I saw a way to switch between the Noise generator and external audio.

Is this the way to go and should I use resistors or capacitors to wire in the Audio Input?

If there is a way to wire more than one input by mixing signals, that would be even better.