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Subject: NJM2069 Levels

From: ackolonges@...
Date: 2015-02-11

Hi group,

I'm in the process of trying to build a VCF / VCA module around an NJM2069 chip pulled from a dead Poly-800. I'm referring to the schematics in the Poly-800 and DW-8000 service manuals as well as the NJM2069.gif in the downloads section. I'm running it off +/- 5v and trying to be as careful as possible not to kill the chip since I only have one.

I was wondering if anyone from the list who has an open Poly-800 and an oscilloscope would be able to check some of the signal levels going into and coming out of their NJM2069 chip for me so I know what safe and optimum signal levels are?  In particular I'd like to know the voltage going in to the Resonance (pin 4), Cutoff (pin 13) and VCA CV (pin 9) at their minimum and maximum values. Also I'd like to know the levels (volts peak-to-peak) of the signals coming into the chip at pins 19, 20, 21 and 7, as well as the signals coming out from pins 5, 6 and 10.  I would really appreciate it and I think it would also help others who are interested in working with the chip.

Thanks a lot!