Voyager XL - mono output only for some filter modes

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David Smyth
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Voyager XL - mono output only for some filter modes

Post by David Smyth » Sun Jan 26, 2020 4:47 pm

Hi there,

I have noticed recently that when using my Voyager XL in stereo (using 2x jack outputs, or headphones from the headphone output), the signal will cut out to one side only depending on the filter mode (dual LP = one side only, LP/HP = both sides).

I understand different filter modes give a stereo effect however I thought if there was a lack of stereo effect, both sides (L & R) would equally carry the same mono signal. The documentation isn't immediately clear to me on this.

Is this usual behavior or is there some servicing required?

Thanks!

David
NZ
Last edited by David Smyth on Mon Jan 27, 2020 3:12 pm, edited 1 time in total.
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

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ummagumma
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Re: Voyager XL - mono output only for some filter modes

Post by ummagumma » Mon Jan 27, 2020 1:40 pm

only thing I can think of is the "spacing" control, if you have it set extreme L/R it can cut the volume, depending on the patch

but if it's set in the middle, that should not happen

maybe twiddle the spacing knob a bit, could be dirty/defective?

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Re: Voyager XL - mono output only for some filter modes

Post by David Smyth » Mon Jan 27, 2020 3:11 pm

Cool thanks - I'll experiment with the filter spacing control for the patches in which it happens and report back.
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

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ummagumma
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Re: Voyager XL - mono output only for some filter modes

Post by ummagumma » Mon Jan 27, 2020 7:32 pm

I just messed with mine for a bit:

-spacing
-filter cutoff
-amount to filter

knobs all interact significantly, and I could lose one stereo channel easily by adjusting them. hopefully that's all it is?

good luck!

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Re: Voyager XL - mono output only for some filter modes

Post by David Smyth » Tue Jan 28, 2020 5:37 am

ummagumma wrote: Mon Jan 27, 2020 7:32 pm I just messed with mine for a bit:

-spacing
-filter cutoff
-amount to filter

knobs all interact significantly, and I could lose one stereo channel easily by adjusting them. hopefully that's all it is?

good luck!
Thanks for taking the time to run tests and provide tips - I appreciate it!

I have been experimenting further however it still seems not right to me. Regardless of filter cutoff, spacing, and amount to filter control positions, I found the following:

When playing a note in highpass/lowpass filter mode, there are two signals, as you'd expect, however with more signal detected on the left side. The left signal is stronger than the right according to my DAW by about double (visually only) in terms of the meters.

(I'm not sure if this skewed stereo signal is a good/bad thing or by design - I've been told when recording digital stereo piano not to worry about one side dominating with respect to signal strength).

When switching to dual lowpass filter mode, the right side's weaker signal remains but the left signal drops to very very minimal levels. You can only just hear the isolated left side when you crank the monitors and synth up. If you pull out the right side jack output cable, the right's signal is summed to the left side for mono output, hence why I haven't noticed this too much - I have been using the synth with a mono output for the past while. When compared to the strength of the left side signal in first scenario I described (highpass/lowpass filer mode), it doesn't seem ideal, or to be working correctly.

I'm not sure the spacing is working either.. I'm finding it hard to notice any difference with it in any position. Seems dead and possibly related.

To confuse matters slightly further, I'm pretty sure my XL headphone output's Left and Right are wired backwards from the main output's Left and Right jacks. Is yours this way? Do you think it is like this for on stage monitoring (facing the crowd) or an error in my unit's assembly?

Anyway, I'd say something is up with the filter section and/or vca(s) circuits maybe, and they might need servicing.

I'm keen to hear any opinions on these issues.

Cheers,
David
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

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Re: Voyager XL - mono output only for some filter modes

Post by ummagumma » Tue Jan 28, 2020 1:16 pm

spacing should have a dramatic effect, when you pan it

if you enable the visual feedback in the display, can you see the values changing as you turn the knob?

ps set filter cutoff to around noon

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David Smyth
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Re: Voyager XL - mono output only for some filter modes

Post by David Smyth » Tue Jan 28, 2020 3:18 pm

ummagumma wrote: Tue Jan 28, 2020 1:16 pm spacing should have a dramatic effect, when you pan it

if you enable the visual feedback in the display, can you see the values changing as you turn the knob?

ps set filter cutoff to around noon
Yea I have the visual feedback on in the display and the values do change, but there is no difference in sound. I have tried this with the filter cutoff in various positions. Therefore I believe it's not working correctly, along with my filter mode issue.
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

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Re: Voyager XL - mono output only for some filter modes

Post by ummagumma » Tue Jan 28, 2020 10:15 pm

ah, that sucks!

yes, appears to need a tech

as a hail mary, you could reinstall the OS & firmware

or open it up & try reseating cables etc

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Re: Voyager XL - mono output only for some filter modes

Post by David Smyth » Tue Jan 28, 2020 10:46 pm

Ah yes, I could try reinstalling the firmware - good idea! I've also contacted Moog Music tech to get their thoughts.

Will keep ya updated..
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

Moritz
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Re: Voyager XL - mono output only for some filter modes

Post by Moritz » Mon Nov 30, 2020 10:32 am

Hi,

my XL has the same issue, were you able to fix it or locate the error?

Best regards
Moritz

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Re: Voyager XL - mono output only for some filter modes

Post by Cavimaster » Tue Dec 22, 2020 5:16 am

Hi,

Exactly same issue with my electric blue :(

I suspect the "famous" MUX problem, but I'm not sure.
> CHIP CD4052 U36 or U51 defect.

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Re: Voyager XL - mono output only for some filter modes

Post by David Smyth » Wed Feb 10, 2021 12:37 am

Sorry I haven't been active in a while about this issue. I still have the problem and am looking at getting the unit looked at. Will keep you updated on any findings.
Minimoog Voyager XL, Little Phatty Stage II + CV Output Mod, 2x Slim Phatty, Minitaur, MP-201, EP-2, 2x CP-251, MF-102, MF-104M, MF-107

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Re: Voyager XL - mono output only for some filter modes

Post by sas » Tue Aug 02, 2022 3:14 pm

Hi!

I'm a new Voyager XL owner. I have a same problem. There's sound only one side (right).
Could you tell me please what is the solution for this?

Thanks,
Attila

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