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CV > Voyager = Ground Loop

CV > Voyager = Ground Loop
« on: November 27, 2016, 05:14:38 PM »
I connected the CV outputs from the Pro 2 to the Moog Voyager and I got a terrible buzz that sounded like a ground loop. No matter what I did I could not get the buzz to stop. I would have tried lifting the ground but I did not have the proper adapter.

Has anyone else experienced this?

Is this a known issue with the CV on either one of these devices?

Re: CV > Voyager = Ground Loop
« Reply #1 on: January 03, 2017, 12:24:15 PM »
I'm interested in this solution as well.  I've tried unsuccessfully to trigger the following synths via Pro 2 CV and gate out: Sub 37, Slim Phatty, and System 1m.  I've never experienced ground loop noise but pitch tracking was un-achievable.  I'm too wary to try it with my Voyager in fear that I might break something.  So as it is I'm only bare scraping the Pro 2's capability.

CV in from an external source directed to a Pro 2 parameter works as expected.

Re: CV > Voyager = Ground Loop
« Reply #2 on: January 03, 2017, 08:33:29 PM »
Well I figured it out (for the Voyager)!  Make the following settings on the Pro 2:
-In the MOD matrix: assign note number to CV out 1 and amount to 126; assign DC to CV out 1 and amount to -51
-In the Pro 2 Global settings set CV 1 Out Scale to -127
Now run the CV out to the Voyager ENV Gate In and set the ENV. GATE to Keyboard (I know counter intuitive but trust me).

Here's how I figured it out.  Using the VX-351, I took a voltmeter and measured the CV out from the Voyager and found that ~0 Volts was E below middle C.  The E above middle C was ~0.94 Volts.  So its about 0.94 Volts per octave.  I also measured the gate voltage and it was ~4.94 volts.  From there I turned to the Pro 2, set note number to 127 (as in the manual) and adjusted DC offset and it got kinda close but more than 1 volt per octave.  So I went to global setting and adjusted the CV scale.   It was almost perfect but not quite.  Finally I adjust the note number value in the MOD matrix to 126 and its now spot on.  I'll make a YouTube video/ tutorial in the coming days to show this.

Cheers!

Re: CV > Voyager = Ground Loop
« Reply #3 on: January 03, 2017, 08:54:05 PM »
A few corrections: set CV scale to 72; plug Gate out to ENV Gate In on Voyager and plug CV Out 1 to Pitch in on Voyager (I forgot to add that in the earlier explanation.  Also do set Voyager to external ENV.  I found I had to flip the switch twice after turning the Voyager off.  All should be in order.  Cheers

Re: CV > Voyager = Ground Loop
« Reply #4 on: January 06, 2017, 12:20:18 PM »
Hi B,

What kind of cables are you using? I've got 1/8" TRS to 1/4" TRS and getting ground loops no matter what. Are you usingsomething different?

Re: CV > Voyager = Ground Loop
« Reply #5 on: January 06, 2017, 01:57:58 PM »
Hi B,

What kind of cables are you using? I've got 1/8" TRS to 1/4" TRS and getting ground loops no matter what. Are you usingsomething different?

I'm using all TS (unbalanced cables).  1/8 TS from Pro 2 gate to 351 attenuator 1 at about 2 o'clock.  1/4 TS from attenuator out to ENV in.  1/8 TS from Pro 2 CV1 to 1/4 TS pitch.

Re: CV > Voyager = Ground Loop
« Reply #6 on: January 07, 2017, 09:17:43 PM »
Hi B,

What kind of cables are you using? I've got 1/8" TRS to 1/4" TRS and getting ground loops no matter what. Are you usingsomething different?

I'm using all TS (unbalanced cables).  1/8 TS from Pro 2 gate to 351 attenuator 1 at about 2 o'clock.  1/4 TS from attenuator out to ENV in.  1/8 TS from Pro 2 CV1 to 1/4 TS pitch.

I've been using TS cables as well. Not sure why I was thinking TRS...memory is starting to fade, I guess.

I don't have a 351 or 251. I'm just plugged straight in from Pro 2 CV1/CV2 to Voyager Pitch/Env Gate. Do you experience any unexpected noise when going straight in to the Voyager?