Help! More whining issues.

Tips and techniques for Minimoog Analog Synthesizers
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Mattew96
Posts: 13
Joined: Tue Jun 26, 2012 9:19 pm

Help! More whining issues.

Post by Mattew96 » Fri Jun 12, 2015 5:22 pm

So I have a Select series, and I knew there was an associated whine due to the lights. I have to ask for some help!
First of all, this causes radio interference in my living room, such that my oscilloscope picks up the whine while both taking a measurement and while the probe is simply free to the air like an antenna
This isn't such a huge problem because I can turn the voyager off (even though it is inconvenient).
Huge problem:
With the CV expander...
Plug the LFO output into the Seq Trig in of the JX-3p, the trigger works but there is an instant whine that wavers around 3.087 kHz present on the output of the 3p. This is only true if I plug into any Voyager CV outputs, and not other synths, and does not diminish with the reduction of panel brigjtness.
I haven't tried LP filtering the signal, but I shouldn't have to.
Please help!

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MRNUTTY
Posts: 319
Joined: Fri May 02, 2014 2:54 pm

Re: Help! More whining issues.

Post by MRNUTTY » Sat Jun 13, 2015 8:50 am

These is a factory fix for the whining. My EB whines too, but I have little use for a the backlight so it's not a burning issue. Do you get the CV issue with the backlight off?
Voyager Quiet II Technology Upgrade

This feature shipped stock on all Select Series Voyagers and Electric Blue Voyagers with a serial greater than 850.

Anniversary Edition Voyagers preceded this upgrade. This upgrade is not available for Signature or Anniversary Edition Voyagers.

With the introduction of the Minimoog Voyager Select Series, Moog is pleased to incorporate Quiet II Technology for ALL Select Series backlighting.
Moog was at the forefront of this technology with the blue backlit front panel of the Minimoog Voyager Electric Blue model; a stunning new look never before seen. Now Moog Engineering has incorporated a new, quieter version of this backlighting technology dubbed: Quiet II Technology

All Minimoog Voyager Select Series, including the Electric Blue, include the Quiet II Technology. We are very pleased to offer the Quiet II Technology to our Electric Blue customers as well.
VoyagerEB, Minitaur, LittlePhattyII, 4xSlimPhatty, Sub37, MF[2x101,2x102,103,104M,105,105B,105M,2x107,108M], 3xCP251, XV351, MP201;
2xMother 32, DFAM, Subharmonicon;
System 55 and Minimoog clones with lots of mods.

Mattew96
Posts: 13
Joined: Tue Jun 26, 2012 9:19 pm

Re: Help! More whining issues.

Post by Mattew96 » Sat Jun 13, 2015 1:05 pm

Interestingly, I have a new development.

So first of all, it doesn't matter how dim my panel is, the pitch and amplitude stay the same, even if the backlight is off.
Second of all, I don't exactly know the mechanics of this, but if I only insert the plug to the "first click" of any voyager outputs (not just the lfo square), I can get a good signal with no high pitched tone. Fully inserted the tone returns. I don't know what this means, unless all the plugs are TRS and that means that the tip has some kind of bleed while the ring is clean somehow...
I hope this analysis makes some kind of sense.

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MRNUTTY
Posts: 319
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Re: Help! More whining issues.

Post by MRNUTTY » Sat Jun 13, 2015 5:15 pm

Hrm, so at least it's not the backlight noise directly. Another source of constant frequency noise is also a switching power supply. However, their operating frequencies are considerably above 3khz to discount this as a direct cause. It is conceivable that either a switching supply, or the backlight, in such a way as to provide for the symptoms you're plagued with. Another alternative is some failure mode of the purely digital circuitry that may cause a constant frequency getting 'into the mix' so to speak. I'm not familiar enough with the internals to suspect with the partial insertion of an output jack may signify.

I have to install a XV-351 modification inside the Voyager this weekend. I'll poke around, maybe get some ideas. Sorry you've got gremlins, it's damn irritating to be sure!
VoyagerEB, Minitaur, LittlePhattyII, 4xSlimPhatty, Sub37, MF[2x101,2x102,103,104M,105,105B,105M,2x107,108M], 3xCP251, XV351, MP201;
2xMother 32, DFAM, Subharmonicon;
System 55 and Minimoog clones with lots of mods.

Just Me
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Location: The Great Southwest

Re: Help! More whining issues.

Post by Just Me » Sat Jun 13, 2015 6:30 pm

You have a ground loop issue. Good luck chasing those gremlins!
"Music expresses that which can not be said and on which it is impossible to be silent."

Mattew96
Posts: 13
Joined: Tue Jun 26, 2012 9:19 pm

Re: Help! More whining issues.

Post by Mattew96 » Sun Jun 14, 2015 7:36 pm

In the end I do think it's a funky power supply in the voyager. This is because the weird tone goes away when I plug an external supply into the adjoined CP-251. The LFO LED also brightens upon the introduction of external power.
Does anyone have a reference for the parallel connector pinout on the voyager so I can check the supply line?

Just Me
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Joined: Fri Feb 27, 2009 11:46 pm
Location: The Great Southwest

Re: Help! More whining issues.

Post by Just Me » Sun Jun 14, 2015 8:53 pm

That is a known trouble. Always power the CP from a wall wart and NOT the Voyager.
"Music expresses that which can not be said and on which it is impossible to be silent."

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MRNUTTY
Posts: 319
Joined: Fri May 02, 2014 2:54 pm

Re: Help! More whining issues.

Post by MRNUTTY » Sun Jun 14, 2015 9:20 pm

ground loop is always a possibility. The 3K noise is what peaked my interest.
VoyagerEB, Minitaur, LittlePhattyII, 4xSlimPhatty, Sub37, MF[2x101,2x102,103,104M,105,105B,105M,2x107,108M], 3xCP251, XV351, MP201;
2xMother 32, DFAM, Subharmonicon;
System 55 and Minimoog clones with lots of mods.

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