Vo Power Scare . .. what are the power specs for the Moog?

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Joined: Mon Jul 11, 2011 4:41 am
Location: Dallas, Tx

Vo Power Scare . .. what are the power specs for the Moog?

Post by Croyote » Sun Oct 21, 2012 2:58 am

Today, I paid a visit to a local company which builds all of my guitar cables to pick up an order of patch cables.

I took the chance to show them the Moog Guitar because I was interested in trying out a Neutrik Timbre Cable for the Piezo channel, and to demonstrate the electronics to find out among other things if they could custom build me a colored 5 pin cable for the XLR out.

As they themselves had suggested, the Timbre Cable turned out to be a dud with no discernible effect on the Piezo Out (don't buy one). While I was demonstrating the XLR Channel I pointed out my power supply to the Pedal.

As a side note, When I ordered my Vo to replace my E1 I chose to stick with the Vo power supply because it has a metal cap that covers the tip of the pedal power input and screws on flush against the pedal housing. I've had problems with determining if the E1's screw-wheel attachment was fully secured in place several times. However, the tip of the power cable was connected by a very stiff short inflexible wire seemingly wrapped with electrical tape to the AC filter that then connects to the power adapter.

I pointed out the inflexible wire to the technician, and she took it and observed the tip and wire, and said "oh this is poorly sodered . . . it could easily break . . . Let me replace this wire and fix it for you."

"Please keep the metal cap on the connector" I told her.

She went to work on the wire, and I resumed playing through the piezo out into one of their modded tube amps.

15 minutes later she came back, with an improved looking wire. I started packing up, and then realized I should try it. We plugged it in, and set up, and then the amp made a sound like "Duk-Duk-Duk-Duk" . . . after a few seconds I realized that the cable must have been wired the wrong way.

I recalled my email conversation with PW at MoogMusic in which we had talked about my 104SD that stopped echoing due to being exposed to correct polarity after being exposed to reverse wiring in my house from its inception. Also, I recalled how Moogerfoogers are always wired with Negative Voltage and said . . .

"Oh no stop it!. . . . Was it wired for negative voltage because I think it's supposed to be."

"Negative voltage . . . Really?! I forgot to check it . .. I just assumed it was positive. I will fix it!"

"Let me check the website on my phone and see what it says . . ."

I proceed to download all the Moog Guitar PDF's on the website . . .and there was no pertinent information in any of the Moog Guitar manuals regarding the proper polarity. In fact, there are no specifications for any of the power supplies needed to run the Moog Guitar included with the materials that came with either of my Moog Guitars as I recall - and now that I've checked the manuals I am sure there isn't any documentation.

She wired it for negative voltage and checked the tip with a voltmeter "-23.98 - 24.00" We plugged it in, and the guitar quickly fired up (quicker that usual) I noticed immediately that the ladder filter worked fine as I swept the range, but it seemed slightly more resonant and intense. As I switched on the Vo power, I felt that the Vo Power was weaker than I recall at the halfway setting and really required a full turn to get continuous sustain and seemed to kick in slower.

I brought it back home and tested it with my rig. My feeling is that the output was actually boosted, but that the resonance seems more intense (maybe overdriven?) and that the Vo output is weaker in it middle knob settings than I recall and seems to take longer to trigger. My Bogner Mojado amp actually started to really squeal like a banshee and vibrate when hitting a certain range of the frequencies with almost no volume (could it just be the responsive Celestion V30?). The output attentuator wheel was pushed fully forward before and after the wire fix.

So my question is: Could the electronics of the foot pedal or the guitar be damaged by sending positive voltage through the power supply to the pedal in this way?

I've submitted this question to my friends at Moog Support, but I posted the email/story here to elucidate a point and ask if any one here has had similar issues?

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Joined: Thu Nov 29, 2012 3:31 am

Re: Vo Power Scare . .. what are the power specs for the Moo

Post by Crowyote » Thu Nov 29, 2012 3:38 am

Hey guys,

I'm back . . .It seems somebody must have blocked my old account after my last few posts.

Let me assure you that I am a lover of the Moog Guitar.

IT seems that some of us who purchased Paul Vo's received power supplies that do not indicate the proper polarity.

The proper polarity is negative current, positive tip.

So far, I've had no problems with the guitar. The issues that occured seemed to be due to a need to change strings and perhaps the wrong settings on the knobs. I've been assured that diodes likely protect the current from damaging the instrument . . .but it's not a 100% assurance

However, I do noticed what might be a slight oscillation in the operation of the electronics, that is, the sound has a peculiar pulsation when using full Vo power. It is not obtrusive, and I wonder if other Vo Users have noticed it as well.

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Joined: Fri Oct 21, 2011 10:20 am

Re: Vo Power Scare . .. what are the power specs for the Moo

Post by thebrushwithin » Sat Dec 01, 2012 11:48 am

I play my E1M a lot professionally, about about 30 hrs. per week, and I have experienced really strange oscillations, with turned up full Vo power. I think it is because I got away from using the Moog strings, as I have read on some other posts, so I am going to try Moog strings again, although I don't care for their gauges (too heavy on the low end compared to the high end). I hope this solves it.

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