(Osc 1-OK, Osc 2-noise, Osc 3-click)^4 = ?

[Snoozr]

Hi again everyone,

I thought I would try to solve a more basic and puzzling problem before I move on with my SID.  I had 2 6581s and after checking in Rutger's editor (which is really great!!) I found they both had this same characteristic which is Osc 1 is perfectly fine, Osc 2 makes a shriek on keypress, and Osc 3 makes a quiet click on keypress.  I had seen on the forums that the 6581s were often dicey so I thought - well maybe it's the chips. 

I very recently bought 2 more 6581s from a fellow midiboxer on ebay (really nice guy BTW) who had tested them on his workbench and said all 3 oscs were fine.  So that was great.  However, when I plugged them in to my setup, I got the same deal: Osc 1-OK, Osc 2-noise, Osc 3-click.

Having 4 chips with the same characteristic (especially now) makes me wonder whether I got something wrong.  As an additional check, I built a completely separate 2nd Sid module with a 2nd Smash board just in case my first one was bad.  I tested the chips in there.  Still the same situation.  I used the 7812 regulator and the 4701 caps on Smash's boards.

I was wondering if anyone has had a similar situation and can point me in the right direction.  I thought maybe it's a soldering issue with regard to just Oscs 2 & 3 and so I tried to look up on Wikipedia which SID pin corresponds to which oscillator but I couldn't figure it out.  The only thing I can think of is maybe I goofed up the core (although it powers up fine and works well with MidiOX). ALso I have to run the Sid module on a separate 15v because my C64 power supplies weren't good. I read this might add a bit of noise but didn't think it would be Osc specific.

I'm attaching some audio files in case anyone wants a listen.  Chip 1 Lead Patch.mp3 is a recording based on the first patch in the patches bank.  I did 2 keypresses for the default patch, then 2 presses for Osc 1, 2 presses for Osc 2, and 2 final presses for Osc 3.  Lead Patch sounds fine as a default because it doesn't seem to use Osc 2+3. 

Chip 1 Techno PWM.mp3 is from the 2nd patch in the bank.  Again, 2 presses for default, Osc 1 only, Osc 2 only, and Osc 3 only.  It uses Osc 2+3 and so sounds bad as default.

Chip 2 Lead Patch.mp3 is like the first recording but with one of the ebay chips. 

There's a little bit of hum between tones - that is ye olde Fender guitar amp.

I guess worst case scenario is that I can just take what I have and get 4 oscs out of 4 chips, but as any synth player knows it would be a shame to throw away 2/3rds of one's polyphony.  Thanks for any thoughts !!! 

Chip 1 Lead Patch.mp3

Chip 1 Techno PWM.mp3

Chip 2 Lead Patch.mp3

[Smithy]

Is it possible that some of these patches use Mixed Waveforms?

Have you tried playing the oscillators without using patches, just by say playing the standard waveforms via midi?

This is most likely not the case but one possible reason nonetheless.