Quantix 8 input problem

[lexvortex]

Hi,

I have built two quantix 8 modules and both exibit the same problem, I can't get either to function as a wavetable osc or quantizer. I'm guessing that its something to do with the input side of things because I can load a sample into it and it will play it back like it's supposed to and the MIDI to CV converter works too.
Has anybody here built this module that can help me out? I've hooked up the output to my oscilloscope and have my MOTM 300 Osc saw tooth wave driving the wavetable and tried calibrating it but nothing happens. I've double checked every component on the board and all the wiring and checked the voltage for all the ICs and they all check out good. Aside from the input problem everything else seems to function correctly.

Thanks for any tips or direction for trouble shooting,
Dave

[etaoin]

What is the clockrate you're getting from U6?

Mine was too high for the ADC, I had to change R6 to bring it down.

[lexvortex]

Hi Etaoin,

When I measured it it was close to the target rate (I can't remember what that was), maybe I'll put in a trimmer instead of the 1k resistor in there now and see if I can dial in closer the right value. What value resistor did you end up using?

Thanks for the tip
Dave

[etaoin]

I have 2k in there.

I think it ran at about 725 kHz with 1k, which my ADC didn't like at all. It's running at around 500 KHz now.

[lexvortex]

Success!! I replaced the 1K resistor with a 2K 20turn pot and got it read the input I then put all the trimmers in because I couldn't get the waveform to look right in my scope, the down slope of the sine function sill looks a bit funny when zoomed right in but is the best I could get it.

Thanks again for the tip,
Dave

[Funky40]

hi,

Marc Bareille has begun to wrote a Manual for the software:
http://m.bareille.free.fr/modular1/quantix8/qtx8_softdoc.htm#description