Wiardgroup

I had this problem (horrible crosstalk throughout the system), stemming from a single power supply used to power a rack of Wiard modules (and just Wiard).

But I can't remember whether this was the one that was caused because the adjustable power supply I was using had gone considerably under 15v (which was easily fixed), or whether it was the one caused by a defective power supply that I had to trash because I couldn't troubleshoot the problem.

Does reducing the number of modules/components connected to the power supply improve the situation?  I would start by connecting only one Wiard module (presumably VCO) to the power supply and testing its performance, then connecting more modules one by one until you start seeing the problem.  If you see the problem with only two modules connected, then I'd have to believe the power supply is defective.

Did I ever tell the list about the time I powered up my Wiard for a gig and was greeted with the worst 60Hz hum I've ever heard?  Fortunately, the sound guy did a good job of notching it out.  But it wasn't until after we finished playing that I actually looked at the power supply ... one of the two large filter capacitors had been sheared right off and was presumably still on the floor of the venue we'd played the night before (a pretty rowdy warehouse show).

(Yes, I know it's not the best idea - and probably a violation of OSHA regulations - to use an open-frame power supply with a live rock band, but I never claimed to be the brightest bulb on the Xmas tree.)

Doug

-----Original Message-----
>From: Norman Fay <vietgrove@gmail.com>
>Sent: Sep 15, 2010 2:15 PM
>To: wiardgroup@yahoogroups.com
>Subject: [wiardgroup] power supply faff
>
>Hello!  I have a question about the power supply for my Wiard &
>sort-of related synthesizer.
>
>The entire instrument is powered by a Cynthia "major power supply"
>which is this massive lump whch can supposedly power 3A, I'm sure it
>was 5A when I bought it, but cyndustries website says 3A.
>
>Everything appears to work OK, as in, the oscillators track fine and
>have stable tuning, BUT, I am getting a lot of problems with crosstalk
>between modules.  The Wogglebug bleeds into nearly everything,
>including the audio out of an E-Mu sampler I have on the same power
>bar.  I recently built a Jurgen Haible "living VCO" module - which is
>great!
>
>http://www.flickr.com/photos/16804034@N00/4530425459/
>
>but, there is a very faint vibrato audible from all of the other
>oscillators, and the envelator, if it's switched to cycle mode.
>
>This all sounds rather similar to reported power supply issues from
>other modular synthesizer users.  I have the power arranged as
>follows:
>
>the incoming power goes to a splitter box in the lower cabinet, then
>to a box in the upper one.  there are a pair of distributor boards in
>the bottom cab, and a single one in the top, which come from the
>boxes.
>
>I seem to remember some post from GR in the archive of this group
>suggesting using more than one power supply for different types of
>module, but I can't find it - yahoo's search isn't very good I don't
>think.
>
>does anyone have any suggestions as to how I might power up this
>monster to eliminate or reduce these hassles?
>
>Many thanks.