Moog Music Forum

Everybody with monophonic synths intermittently gets mild audible popping sounds on fast amp envelope attack when the filter cutoff is low enough. Now imagine those "attack pops" to be overtly loud, and increasing amp envelope attack up to 40% of the maximum, and still hearing them. Couple that with the weird behavior in that when amp envelope Release is increased and notes are played in short succession without legato, it causes amp envelope Attack to noticeably increase. (albeit without the pops) This is what my Voyager RME has done since it was purchased new.

I typically use only the Right output, and send the Left one back to the audio input, only engaging the External switch manually, and never saving patches with it on.

If you look in an audio editor at a recording of the Voyager at these settings, the pops show up as a fast rise time up to around -30db when recorded loudly, no matter what the phase of even one oscillator is, and no matter what the amp envelope attack is(up to around 40% of maximum attack time) at the time the VCA fires.

I sent the unit to Moog Music because of this and a bad headphone amp, but they said they couldn't reproduce the popping behavior. I even explained over the phone that I theorized the problem to be a latency of a few milliseconds when the VCA opens, after the beginning of the CV slope of the envelope.
ie. the VCA's gate circuit fires after the envelope signal has already started, cutting off the beginning of the slope. I told them this, I spoke to Tony I believe, and he checked and couldn't find anything wrong. He had also suggested a DC offset in the audio outputs and couldn't find any. He updated the OS to version 3.3, but I still hear the popping.

So here I have my SCI Pro~One replacement that I can't really replace it with because of this screwy VCA problem.
Very important to remember is that the popping isn't noticeable until cutoff is sufficiently low enough. Perhaps the popping is always there, just masked by high frequencies with a high enough filter cutoff.

Anyone else notice this with theirs?

Welcome to the forum.

I have noticed some pops somewhat similar to what you are referring to, ive tried changing the waveshapes and everything to try to eliminate it. Basically, until I read this post I just accepted it. Im also not an engineer, don't have an oscope or anything either.

I think there are various threads in the forum about this...do a search for snappy envelopes and see what you come up with.

Be patient too.

I hope you get this fixed because the voyager is a definate piece of work!

Respectfully,
Eric

Well, I found 3 threads on this here, here and here but there seems to be no answer as to why I can still hear the popping as the amp envelope attack is raised to near 40% of maximum, and why when I look at the recording in an audio editor, I see a fast rise time to around -30db that suddenly slows its curve significantly for 3 times the number of milliseconds up to -6db, whereever I hear the popping.

Seeing as my SCI Pro~One does not do this with very similar sounding patches, and both synths have free-running oscillators and fast envelopes, I can only assume this is a design flaw that people just live with. I've lived with it since July 2007, and am getting rather annoyed at it now.

Is this Cat by chance?

Since last year I've talked with an engineer that might have some ideas about this... email (my name) at moogmusic.com and I will get back in touch with him about it, see if we have some new ideas. I have a better idea what you're talking about now.

Thanks,

Amos