@J3RK thank you for your response . I used the factory preset as an concrete example of where I encountered the noise initially . Though it has popped up several times when I would make a patch from initialize . Judging by your response I’m thinking its specific to my unit but I could be wrong . Here is what I posted initially on the sequential forum : Prophet Rev 2 noise
the downloadable file is audio of my synth and a basic patch I made. From what I’ve seen, the old mophos had this sort of amp env “zipper” too as it’s described.
. I apologize for all this cross posting but am at work and can’t record the sound atm .
No problem at all, and thanks for more information to go by. I’ll check out the example as soon as possible. It could very well be your unit. I’ve had two, one DSI version, one Sequential version (same hardware, but one was quite a bit newer) and never noticed any issues. I’m fairly sensitive to these sorts of things (I design synths in my spare time).
my guess is he would just like to be able to know why F2P7 is doing it; i.e. what parameters should be changed to make the click go away. I have encountered this a few times in making my own patches, and it has stumped me. I didn’t end up liking the patches in question enough to dig further though, lol.
One is the click of the attack where the “front” of the waveform is chopped off. This is normal behavior in a synth with free-running oscillators. You can mitigate that by setting them to reset on key. (there’s a menu item somewhere for that if I remember correctly) I can tell that’s what this portion is because it hits differently on each note played. This is usually considered somewhat desirable. The differing phases in free running oscillators and VCA behavior is part of the analog charm.
There’s another thing I’m hearing, and I’m not sure if it’s what you’re talking about, as it could almost be attributed to compression artifacts of the mp3. There’s a very faint higher pitched trailing click thing that I can hear after many (but not all) notes. If this is what you mean, I could think of a few things it could be.
It could be a small “ping” of the filter on the trailing end. It’s possible that calibration could solve this. (be sure to set all knobs to their default (zeroed whether unipolar or bipolar) positions before calibrating too. Sometimes doing it more than once helps too. If it’s not filter related, this won’t help.
It could also be some kind of digital artifact from the effects if they aren’t zeroed out completely, but I’m not sure that calibration has any impact on that. That would probably be bug territory.
It would be interesting to know if varying envelope settings (especially depth) might have an impact on this.
Intersting.
Personally, if that only came up once in a while, I’m not sure it would make me want to ditch the synth, but it’s kind of annoying, and I’m sure there must be some way to fix, mitigate, or at least report it directly.
It does sound like it reduces or disappears when you added a bit of release to the envelope.
Awesome ! Thank you for the advice ! I will give zero-ing out all the pots and recalibrating several times a try , I have recalibrated but not as you explained . And that sound at the end of each played note is what I’m referring to . The mp3 was just the smallest and quickest way to export but I noticed it first in my headphones directly out of the synth . I’ll report back later
@Bloop thanks for this . very comparable to what I’m experiencing so it might just be a quirk of the synth.
@J3RK, heres some more messing around on an init patch playing the lowest note on the keyboard only adjusting the attack and release of the Amplitude envelope and cutoff. The calibration didnt affect it though i suspect as you mentioned if its anything other than the filter it wouldnt
I think this is the case. After providing audio and spectrum analyser examples to DSI support they assured me that my units were not behaving in ways that are unexpected.
I created a new custom Init patch with amp envelope defaulting to 64 and I’m much happier with all of my sounds. No more grindy metallic harmonics
Ps the audio example I posted above had both oscillators turned off and the sound was just filter self oscillation
It could definitely be a quirk. It’s also maybe possible that it’s just part of the envelope and a little blip of the VCA or something like that. There are all kinds of tests one could do, but honestly, is this how one uses this synth? Everyone is different, but I hardly imagine this coming through in a composition or mix. I completely understand being annoyed by things like this, but I also have to remind myself what I use these things for.
Not sure that this would bother me in actual use. Academically I find it interesting though.
It adds up pretty quick if you’re recording several layers from the same synth.
The artifacts create frequency spikes which are constantly the same frequency with no correlation to the note played.
“ You’re welcome, I’m glad to be of assistance. Re-listening to our audio files, there are actually two contributing factors to the noise; both expected. The first is as I described in my initial email and generally relates to the VCA. The second is an artifact of the CV sample and hold circuit when modulating the filter frequency. This artifact can be lessened by slowing the attack/release of the filter envelope. Rest assured, nothing is physically wrong with your REV2 in this regard.”
All is well . Just have to try to avoid the clicking
I just read thru their forum, and according to DSI staff it looks like they’ve stopped adding features due to availability of resources in the synth. There’s some pretty angry comments in there over bugs, and it looks like DSI have poured all resources into fixing those and calling it a day for the Rev2.
That makes sense. There are ways to make S&H circuits with low droop, and low charge injection spikes/artifacts, but they require very specific and somewhat specialized and expensive components, and also very careful PCB design. Sequential is more than capable of doing it, but it’s a bit expensive for smallish returns.
for the life of me I’ll never understand people that want something they’ve bought and loved for years to be continuously made better by firmware updates into infinity. as long as it delivers on what was promised when you bought it, you have no right getting pissed at the company for not making it even better after that point.
