When is the next OS revision coming out?


I generally agree, unless you can hear it in the background when the oscillators are turned up as well. (and I can once I heard it in isolation). One reason I sold the Modal 008 was a constant suboscillator bleedthrough that affected the sound of every patch. It made certain quiet/smooth sounds impossible to create.

I’d like to hear from others whether they can hear the noise when playing with the latest update. Listen first with oscillators down, then bring them up and play. If it’s just me/my Parva then I’ll shut up about it.


I’m not sure what the latest update has to do with it – there weren’t any changes that affected the noise floor. Did you notice a change recently?


Yes, any program change messages on the appropriate channel…


I was just testing since the soft attack problem was addressed. I noticed the obvious noise with the oscillators down during testing. I don’t know when it started, just noticed it this morning and wanted to know if anyone else noticed it.


I experience the noise as well… acceptable in a busy song with the parva as one of the sounds. But on a soft song with only the parva playing for example, it’s just too present imho. It’s a lot less than in the old version, but still there :wink:

(as a sidenote: in the CS80/deckard’s dream clone demo’s out there I here a similar noise)


Overall the Parva feels lot better, sounds are better balanced. The high pitched whine in the background is there as it was before, so no change to good or bad here for me.

Still, the voices have “glide” to the waveshape when pitch of a certain voice has to jump over several semitones. This happens for all non SQR waveshapes and it can be heard easily when using OSC 3 TRI for Filter FM.

Brad, I described this effect in detail in private mail to you back then. Can you reproduce the pattern on your machine as well?


I just discovered a major bug. For some reason, the filter resonance gets weaker or wears out in a patch in several hours or earlier. I discovered it when I was attempting to recreate the JX8P’s electric piano sounds in Multi-Mode. The FM patches used for my EPiano patch used a lot of resonance.

If the resonance wears out, most patches that use high resonance will sound different. The only way I can temporarily fix it is to calibrate the VCFs.

I tested this bug by using four patches: a saw wave patch, a triangle wave patch, a square wave patch, and a filter FM patch. All four test patches used a LP4 filter with its frequency set to 70, resonance set to 100, and key amount set to 64. After calibrating the VCFs, I waited for over 30 minutes (the time depends), and the triangle and saw wave patches sounded different. The square and FM patches sounded OK since resonance did not significantly affect the sound. The triangle and saw wave resonant patches began sounding more like sine waves.

By the way, is there any way to make the triangle wave sound less like a saw wave?


I’m sorry, but I’m 99.99% certain that there is no mechanism by which resonance can “wear out.”


What I am trying to say is that the resonance gets softer or goes away. It may also be possible that it’s the filter that is getting out of tune


Brad, I don’t know about others, but the reason I keep trying to point out these things is because I think the Parva is a great synth. If I thought it was crap, I would have sold it off long ago and been done with it.

However, I think you have something special with these oscillators. Even playing simple chords with a one oscillator triangle wave and filter wide open sounds very nice. It’s big and full and pleasant to listen to.

For me, the high pitched whine is the only kink in the synth. It’s not noticeable with 1 or 2 keys down, but if you set the OSC 1 volume to 30 or so and triangle wave and play some basic C maj chords below middle C you can hear how that noise is present in the sound.

Even if it required a hardware mod to the voice cards to reduce that cumulative noise, I’d be more than willing to send my cards in and pay for the modification (unless it was something we could do in the field).

In any case, don’t be discouraged by these comments - these are reports from people that believe in this synth and like everything it does to this point. Cleaning up some of these unfortunate sonic artifacts are (to me anyway) way more important than new features to this already full-featured synth.


I realized that after testing a self-oscillating patch with no modulation involved, the problem I discovered may be due to the fact that the VCF or resonance is gradually changing, as evidenced by the observation that the resonance gradually changes pitch at self oscillation. The resonance inconsistency may be a good or bad thing depending on what kinds of sounds or music I want to make


This makes me think of something. Can you add key sync to the filter?


I appreciate your comments. If you’re up for it, I’d like to compare some measurements of a current-production Parva to your early model. Please give me a few days to come up with a relevant test process.


Sure thing. There’s a long weekend coming up, so if you can get me the procedures/measurements you want by like Thursday evening, I can run a battery of tests for you.


I’ll make a recording of the issue I’m having with mine still too. I do not have enough software or hardware knowledge to know exactly what’s causing it but with the new voice firmware and after calibrating DCOs and VCFs I’m still having a problem with volume and a thumping click in one voice. I’m on holiday at the moment but will record when I get back on saturday.

Also, do you think some deoxit might help out my encoders? They often start to phantom value change.


So you think my filter resonance is going “phantom” too?


A recording would be very helpful. If you’re experiencing issues with the synth, please email me or post on the forum with a description of the problem.

So far, every report of “phantom” parameter changes has been a controller or DAW sending MIDI CC messages. Are your encoders randomly switching between OSC1 and OSC2, or is some other value changing? If they’re not randomly scrolling through menus, then phantom parameter changes aren’t due to faulty encoders.



Will send you an email Brad, rather than clutter up this thread. A genuine thank you once again for the quick response.


Brad - check your messages; I uploaded a couple things for you to review.



I uploaded the tests you asked me to run.
So is my Parva noisier than the current crop or is it the same?