Help! MFOS and Synth.Com issue

abelovesfun · Joined: Dec 17, 2012 Posts: 40 Location: Portland, OR

Help me electro-musicians!

I recently purchased some synth.com modules to go with my otherwise MFOS system. Whenever I seem to try to connect the two though - I seem to run into issues, please see the video I made this morning (no coffee yet when I made it - so my apologies).

The MFOS stuff is running off of two wall wart power supplies, and the Synth.com are running from the simple 8-module power supply they sell.
Any hints as to my issue?

elmegil · Posted: Sat Jul 13, 2013 2:11 pm Post subject:

Without knowing what the DotCom modules are it's hard to say.

A couple of things to look at though...

1) are you sure they have compatible power levels? The MFOS wall wart supplies are +/- 12V or 9V if I recall correctly, the DotCom stuff is +/-15V. Going MFOS->DotCom that should still work fine, but the other way around you could cause grief.

2) make it be the simplest patch possible, whatever the DotCom modules are, just send one VCO, one control signal, and take the output directly instead of routing it further. Too many other things involved muddies the problem.

I somehow think that something must be weird about the grounds relative to the two systems, but offhand I can't think of anything obvious to suggest.

abelovesfun · Joined: Dec 17, 2012 Posts: 40 Location: Portland, OR

@elmegil thanks so much for taking time to look at this. Now I'm thinking that there must be something mechanical going on with the Multi.

I put up a new video just now (it's still processing but will be live here: http://youtu.be/Fq4PQMM6AEs)

Towards the end I use a different set of "Multi"s and that "solves" the issue, so I think the top right jack must be nudging something somewhere it shouldn't be... I have each row of multi jacks grounded to themselves, should there be more grounding?

The MFOS units are running off of two 1A Wall wart power supplies (not combined: 1/2 are running on one, and half on another) and the DOT.COM modules are running off their own DOT.COM power supply.

elmegil · Posted: Sat Jul 13, 2013 5:57 pm Post subject:

If they're properly grounded to each other, shouldn't be an issue. Might check for cold solders....