A trick to make the Voyager sound better

[slirak]

Only one Opamp was changed ( 074)
I allso put in a new headphone jack socket.. but thats another story

Is this "crackeling noise on both outputs.. Main and Headphone ???
best regards
Morten

Hi Morten, I realized that you only changed one opamp, but it's not unlikely that there's more than one 074 in the Voyager. That's why I wondered about its designation.

The crackling is present in both the line outs and the phones out. But not in the effect loop insert point, so the issue is probably either with the filter or the VCA.

/Jonas

[slirak]

Hey, I just went back and checked and actually, the crackling is present at the insert point too.

So it seems, the fault must lie earlier in the signal chain than I thought.

Also, I get the crackling even with no oscillators on, it's enough to turn up the external input level. No need to actually feed anything through the external input, I just have to turn it up.

So maybe the fault is in the mixer section?

Hm. I'm gonna have to open up my Voyager and see what opamps are present in that section. If they're 074's too, we might have a winner.

/Jonas

[MotneN]

Hey, I just went back and checked and actually, the crackling is present at the insert point too.

So it seems, the fault must lie earlier in the signal chain than I thought.

Also, I get the crackling even with no oscillators on, it's enough to turn up the external input level. No need to actually feed anything through the external input, I just have to turn it up.

So maybe the fault is in the mixer section?

Hm. I'm gonna have to open up my Voyager and see what opamps are present in that section. If they're 074's too, we might have a winner.

/Jonas

Hey jonas

Damn annoying.. when a problem like this occour..

How does the "noice" behave?? does it get worse when you turn the knobs?? .. or??
Is it a loud noice ??

best regards
Morten
what have you tried and not tried?

[slirak]

Hey jonas

Damn annoying.. when a problem like this occour..

How does the "noice" behave?? does it get worse when you turn the knobs?? .. or??
Is it a loud noice ??

best regards
Morten
what have you tried and not tried?

Factory resetting and updating the OS (it was 2.something when I bought it) made no difference.

The noise is loud enough to be a problem when you play sounds with few over-tones. More harmonically rich sounds mask it, even though it's still present.

So it's worst with triangle sounds, at low octaves. Here's an example, using just a single oscillator with a tri wave: http://www.webnoise.net/Moog-knaster.wav

Anyway, I just opened the Voyager up and lo and behold, there are two more TL074 on the analogue board, U8 and U30.
They're both in sockets, so I just might try to swap in 837's there too. However, I have a distinct feeling I read somewhere on this forum, that a capacitator may need replacing too. Anyone who happens to know?

Regards
/Jonas

[slirak]

Some more info.

1) I've discussed the TL074 with a group of extremely knowledgable audio engineers AND analogue synth buffs. They rejected the notion that it's unsuitable for audio. We're talking about people who are either analogue audio engineering professionals, or the kind of DIY synth builders that are capable of not only building, but actually designing the circuitry of their own modular systems, from the ground (pun intended!) up - or both. According to them, you can't say whether an LM837 would be better or worse than a TL074, without deep knowledge of the overall circuit design. So their recommendation was that I shouldn't replace the remaining TL074's with anything, if it's not specifically recommended by Moog Music Inc. As it happens, there's a post from Moog tech Amos, saying that U49 should be replaced with an LM837, but nothing was said about the remaining 074's.

2) I've received third hand info, that seems to stem from Moog's support, saying that my 'crackling' issue probably is caused by the combination of an early digital board and a recent OS. The info said that I had two options: get a new digital board, or live with it... Interestingly, in an earlier thread here, one forum member stated that he experienced the very same issue after upgrading his OS.

I've mailed Moog's support, asking for the sysex files for an early OS version. But if anyone of you folks happen to have them, I'd highly appreciate if you could send them to me.

Regards
/Jonas

[EricK]

If your Voyager under warranty?

[slirak]

If your Voyager under warranty?

Not from Moog, it's an SE from 2002. It's under limited warranty from the shop that sold it to me. Problem is, their tech isn't a certified Moog tech... If I can verifiy that the issue is the combo of OS 3.5 and my early digital board, I guess I'm gonna have to have a certified tech fix it and probably pay for it all myself. But at least I'll know there's no use having the shop's tech keep trying to figure it out.

[slirak]

I just realized that you actually can order the new digi board with instructions on how to install it. It's an upgrade from 128 patch slots to 896, so it's not just a possible fix for my issue, but a nice functional upgrade. Not too expensive either, $265.

But I'd really like to get hold of an early OS first, so I can tell whether it's the digi board in mine that's at fault.
Possibly, 2.6 is old enough. But the older the better I guess, for testing purposes.

[MotneN]

I just realized that you actually can order the new digi board with instructions on how to install it. It's an upgrade from 128 patch slots to 896, so it's not just a possible fix for my issue, but a nice functional upgrade. Not too expensive either, $265.

But I'd really like to get hold of an early OS first, so I can tell whether it's the digi board in mine that's at fault.
Possibly, 2.6 is old enough. But the older the better I guess, for testing purposes.

Hey

I'll chek if i have the software some place..
i had to " downgrade" my self back in the days.

had some promblems my self with the 3.0 upgrade ( i think it was 3.0, but i have to chek)

Morten

[MotneN]

I just realized that you actually can order the new digi board with instructions on how to install it. It's an upgrade from 128 patch slots to 896, so it's not just a possible fix for my issue, but a nice functional upgrade. Not too expensive either, $265.

But I'd really like to get hold of an early OS first, so I can tell whether it's the digi board in mine that's at fault.
Possibly, 2.6 is old enough. But the older the better I guess, for testing purposes.

Hey

I'll chek if i have the software some place..
i had to " downgrade" my self back in the days.

had some promblems my self with the 3.0 upgrade ( i think it was 3.0, but i have to chek)

Morten

Hey Again
I got OS 1.5 with boot OS 1.2 / OS 2.1 with banks ABC / OS 2.5 with banks ABC /OS 2.6 / and OS 3.1 to 3.4..
which one do you need?

Best regards
Morten