Soundlab Ultimate troubles

[Benzoil]

Hi everyone,
I finished building the Soundlab Ultimate and I am now trying to troubleshoot this particular problem I'm having. It is cycling through this weird pattern and I can't figure out why it's doing this. Instead of me struggling to describe this pattern, I have attached an mp3 (NOTE: the high frequencies can be pretty brutal so watch your ears/computer speakers ).

The settings on my Ultimate during this recording are as follows:
-All 3 VCOs are set to triangle waveform and PW at 0%
-VCF Initial Cutoff is at 10 and all other VCF pots at 0
-VCA Initial Level is at 10 and all other VCA pots at 0
-Both LFOs are set to triangle and rates set at 0 and Range set at Low
-Attack and Release are set at 0, Mode is set to Gate, and Range is set to Short
-Repeat Gate set at 0
-Sample Rate and Glide are set to 0 except I turn the Sample Rate up to 10 and back down to 0 between 1:37-1:51 of the recording. This is the only human interaction during the recording.
No patches via banana jacks are used during the recording.

According to Ray's schematics the S/H and Repeat Generator sections are not in the normalized signal path, yet when I turn the pots for Sample Rate and Rpt. Gate Rate it effects the signal (without patching to these sections). I've checked my wiring (both intra-panel and PCB to panel) and everything looks correct. Any ideas?
Thanks!
-Benzoil

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SLUltimate_weirdness.mp3
Description:		Download (listen)
Filename:	SLUltimate_weirdness.mp3
Filesize:	2.5 MB
Downloaded:	409 Time(s)

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[RF]

Wow.

I have no idea.
To try to narrow it down...
Is there a single or a couple settings on the panel that cause it to act normally?
What one or two patches cause it to behave correctly, if any?
Did you make any other modifications to the circuit?

Here are some shots in the dark...

Are all the 'Ground' points connected? Are you using a conductive panel for jacks and pots - or otherwise making sure the 'normalized' or patched connections have a ground path?


bruce

[Benzoil]

Hi Bruce,

After re-checking all my ground connections I found that I forgot to ground the Ultimate PCB to the power supply PCB. I had the faceplate grounded to the power supply but not the PCB. Thanks for pointing me in the right direction!

Cheers,
Benzoil