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Oscillator Issues

Oscillator Issues
« on: June 22, 2017, 06:29:11 PM »
I'm having some very strange issues with the oscillators on my Rev2. This is only noticeable on triangle and pulse settings. If I initialize a new patch and set the OSC1 to triangle, it sounds like a triangle for the first 4 notes that I play, then the NEXT 4 notes sound like not a pure triangle, like a tiny bit of saw buzz coming in. Then the next 4 notes are triangle again and so on. Same issue noticeable in pulse mode. Calibration did not fix this (also troubling is that the first time I tried calibrating it froze after the first voice finished and I had to reboot...) Can anyone replicate this issue on their unit? Think this is a hardware issue? Between this and the jumpy pots I'm beginning to get very frustrated and am considering returning my unit.

Re: Oscillator Issues
« Reply #1 on: June 23, 2017, 12:42:48 AM »
On my Prophet'08 I get a tiny bit of bleed from oscillator 2 even when the mix knob is set to 0.  It's not 100% consistent between voices.  It is most noticeable on triangle and pulse settings.  In everyday use I've honestly never noticed it.

Does your problem go away if you set oscillator 2 shape to Off?

To some degree this is a characteristic of an all-analog signal path. Personally, I like the slight subtle variances between voices.  It is, for me, a significant part of the reason I like analog synths.

Re: Oscillator Issues
« Reply #2 on: June 23, 2017, 05:43:58 AM »
Yes, the issue is noticeable even when OSC2 is off. I guess that it is a problem with voices 5-8 which explains the cycling every 4 notes. It is not noticeable in an realistic patch that I would be using but I don't want to have to settle for a malfunctioning unit. If no one else has this issue I will simply return this one and get another one. Unless of course this is something that a software update could deal with.

Re: Oscillator Issues
« Reply #3 on: August 31, 2017, 06:31:08 AM »
I just got my Rev2 16-voice and am having the same issue. I started programming a basic patch and the very first thing I did was change OSC1's waveshape from sawtooth to triangle. The first 8 notes I played were triangle and the next 8, still sawtooth. I tried re-calibrating the oscillators and filters and it seemed to fix the problem, only for it to happen again some time later when I loaded a previously saved patch into the Rev2 via USB/Sys-Ex from the Soundtower app (the patch, FWIW, also used a triangle wave). Half the voices remained basic sawtooth (and this was all in layer A only - I was not in stack or split mode). I re-loaded the same patch and the problem went away. So there's some kind of intermittent bug. I had a hunch it might be specific to the 16 voice version but now I know someone with the 8-voice is experiencing the same problem. Hopefully DSI will fix this shortly...

Re: Oscillator Issues
« Reply #4 on: August 31, 2017, 07:05:50 AM »
Same issue here if it's an issue
IMac Mid 2013, Cubase 9Pro, Prophet Rev 2 8voice

Re: Oscillator Issues
« Reply #5 on: August 31, 2017, 08:04:13 AM »
Serial numbers? Early models or later?

Oscillator issues and bugs, or do I have a faulty synth?
« Reply #6 on: August 31, 2017, 06:26:38 PM »
I've discovered a few issues on my Rev2 and wondered if it was just me, or if others encountered these problems.
I'm on the latest firmware v1.0.7.2.

Issue: 1. If I select a basic program and then select the Pulse wave as on an oscillator, it doesn't sound like a Pulse at all.
It sounds really nasal, almost like a pulse would sound if shape Mod was applied.
To get the Pulse to sound like a Pulse, I have to turn the shape mod to 50% - surely this shouldn't be a requirement from a basic patch, you shouldn't have to shape mod it to sound like it should sound to begin with.
This I feel is just a wrong default in the OS that could be fixed with an update, but my other issues are a little more disconcerting.

Issue 2: I have a similar issue (but not the same as) the issues described in this post...
http://forum.davesmithinstruments.com/index.php/topic,1573.0.html

Basically if I select a triangle wave for my oscillator random notes in the bottom octave of the keyboard will intermittently play a sawtooth instead.

Issue 3: This is the big one...If I create a Basic Program and select the Pulse wave on an oscillator, Notes played at the lower octaves of the synth are intermittently dropped and don't sound at all!!!!
Obviously that's not good! :(

I have tried recalibrating the oscillators and filters using selection 26 in the globals menu, but to no avail - the issues still occur.

A short video showing the issues can be viewed below...
https://youtu.be/1dZM2hYa2qI
« Last Edit: August 31, 2017, 06:32:05 PM by jazzygb1 »

Re: Oscillator issues and bugs, or do I have a faulty synth?
« Reply #7 on: August 31, 2017, 11:09:20 PM »
Very ugly, unacceptable. OB6 USB disconnect and voice issues, REV2 pots issue, and now all this.
Really worried to spend thousands of dollars these products and DSI quality control and testing process.
For the premium prices the products should be rock solid. Additionally, if there is a problem DSI should
just confirm if its a bug, reproduce-able, publish the root cause and corrective action. Publishing a knowledge base/FAQ
of issues on the web (with affected serial#) would also help. There ain't much on the support web.
Personally,  I don't have much confidence in American factories and many are sub-par to China factories (have seen many).  Guess you should contact DSI on their support web.
« Last Edit: August 31, 2017, 11:20:33 PM by musicmaker »

Re: Oscillator issues and bugs, or do I have a faulty synth?
« Reply #8 on: September 01, 2017, 03:21:18 AM »
I can't comment on issues 2 and 3, but issue 1 is definitely not a bug. By default shape mod is set to zero if you initiate the Basic Program. Shape mod set to zero means default Sawtooth, Sawtooth + Triangle, and Triangle waveshapes for the selected oscillator. Shape mod set to zero in case of the pulse wave means narrowest possible pulse width. If you want a square wave, you have to set the shape mod to 50%, which is the common amount for getting a pulse wave on all synths that provide PWM.

I can see how this can be confusing if you expect the square wave to be the default pulse waveshape. I guess the only other way to go about it would have been to put all the default waveshapes for Sawtooth, Sawtooth + Triangle, and Triangle, among the square wave in the centrered position, i.e. where shape mod is set to 50%.

Both design options can make sense and it all depends on whether you define the square wave as the default pulse waveshape or not. But as the front panel clearly says "Pulse" and not "Square," the current design choice is not inconsistent, as you get to hear a pulse wave at its thinnest width when you select the according waveshape in the Basic Program.

MDMA

Re: Oscillator issues and bugs, or do I have a faulty synth?
« Reply #9 on: September 01, 2017, 03:22:46 AM »
I think you're slightly harsh in your judgment of DSI.
The issue with this particular board is obviously one of the voice chips, it would appear that the OP has the 16 voice version as it drops or alters on the 16th note.

DSI are probably the most proactive and approachable bunch of people out there, not all launches are plain sailing and there have been a few issues along the way, but, DSI technical are fantastic and an email to them will soon get you up and running.

I would of thought the quick fix for now would be to remove the faulty 8 voice card and use your synth as an eight voice until DSI send you a replacement.  Just a thought!
DSI Rev2, Moog sub 37, Roland JDXA, DSI Pro 2, Novation Ultranova, Access Virus TI, Roland Juno 106, Roland Alpha Juno 2, Korg KingKorg

Re: Oscillator Issues
« Reply #10 on: September 01, 2017, 08:18:22 AM »
Serial numbers? Early models or later?

My Rev2 16 Voice's serial #: 2816-00333

FWIW.

Re: Oscillator Issues
« Reply #11 on: September 01, 2017, 09:39:52 AM »
This video also explains a problem a friend of mine has for the same thing https://youtu.be/1dZM2hYa2qI

Sleep of Reason

Re: Oscillator Issues
« Reply #12 on: September 01, 2017, 10:13:56 AM »
Same issue here on my 16 voice unit.

Re: Oscillator Issues
« Reply #13 on: September 01, 2017, 10:50:14 AM »
For anyone having issues with any DSI gear, please email our dedicated support channel: support (at) davesmithinstruments.com

It's the fastest way to get an official answer and get support. We apologize for any inconvenience, and I assure you there is a solution for whatever might be coming up for any individual.
SEQUENTIAL

Re: Oscillator issues and bugs, or do I have a faulty synth?
« Reply #14 on: September 01, 2017, 12:06:27 PM »
I can't comment on issues 2 and 3, but issue 1 is definitely not a bug. By default shape mod is set to zero if you initiate the Basic Program. Shape mod set to zero means default Sawtooth, Sawtooth + Triangle, and Triangle waveshapes for the selected oscillator. Shape mod set to zero in case of the pulse wave means narrowest possible pulse width. If you want a square wave, you have to set the shape mod to 50%, which is the common amount for getting a pulse wave on all synths that provide PWM.

I can see how this can be confusing if you expect the square wave to be the default pulse waveshape. I guess the only other way to go about it would have been to put all the default waveshapes for Sawtooth, Sawtooth + Triangle, and Triangle, among the square wave in the centrered position, i.e. where shape mod is set to 50%.

Both design options can make sense and it all depends on whether you define the square wave as the default pulse waveshape or not. But as the front panel clearly says "Pulse" and not "Square," the current design choice is not inconsistent, as you get to hear a pulse wave at its thinnest width when you select the according waveshape in the Basic Program.

I see what you are saying, but I disagree.

I own a Prophet 12 too and the default Basic Program wave shape for a pulse is as you'd expect it to be - square.

Either the Prophet 12's default is wrong or the Rev2's is.

For me it's the Rev2.

DSI I'm sure will put this right in a future update (fingers crossed). :)

Re: Oscillator Issues
« Reply #15 on: September 01, 2017, 12:07:30 PM »
For anyone having issues with any DSI gear, please email our dedicated support channel: support (at) davesmithinstruments.com

It's the fastest way to get an official answer and get support. We apologize for any inconvenience, and I assure you there is a solution for whatever might be coming up for any individual.

Thanks for that, an email has been sent to support as suggested.

Thanks for your help. :)

Re: Oscillator Issues
« Reply #16 on: September 01, 2017, 12:16:14 PM »
Can confirm i don't have that issue on my 8 voice version. Serial 2808-006xx .

However after only 1 day of playing the middle C key started to squeak to a point i had to open it up, remove the key ,lubricate it in some areas. On the box it says made in San Francisco not Hong Kong .... hmm.

Re: Oscillator Issues
« Reply #17 on: September 01, 2017, 12:25:42 PM »
That's right, made in San Francisco. Please keep the conversation relevant, on topic, and constructive. Thanks!
SEQUENTIAL

Re: Oscillator Issues
« Reply #18 on: September 01, 2017, 12:45:58 PM »
Thank you , i believe it is , we are discussing issues we users have , i pointed to an different issue i have, should i open a new thered regarding squeaky keys ? That would be irrelevant wouldn't you agree ?

By 'Made in San Francisco' and selling instruments with price tags of 1.5k-3k it's only normal to expect top quality and not have to fix squeaky keys !?.

More over my Pro2 after a day of not playing it , have sticky keys giving me some resistance until i press them all , only then it becomes playable.

You can understand some frustration i hope ...


Re: Oscillator issues and bugs, or do I have a faulty synth?
« Reply #19 on: September 01, 2017, 12:58:10 PM »
I can't comment on issues 2 and 3, but issue 1 is definitely not a bug. By default shape mod is set to zero if you initiate the Basic Program. Shape mod set to zero means default Sawtooth, Sawtooth + Triangle, and Triangle waveshapes for the selected oscillator. Shape mod set to zero in case of the pulse wave means narrowest possible pulse width. If you want a square wave, you have to set the shape mod to 50%, which is the common amount for getting a pulse wave on all synths that provide PWM.

I can see how this can be confusing if you expect the square wave to be the default pulse waveshape. I guess the only other way to go about it would have been to put all the default waveshapes for Sawtooth, Sawtooth + Triangle, and Triangle, among the square wave in the centrered position, i.e. where shape mod is set to 50%.

Both design options can make sense and it all depends on whether you define the square wave as the default pulse waveshape or not. But as the front panel clearly says "Pulse" and not "Square," the current design choice is not inconsistent, as you get to hear a pulse wave at its thinnest width when you select the according waveshape in the Basic Program.

Paul Dither is correct here in his description/assessment of our implementation. The Prophet Rev2 is the first of our Curtis-based instruments for which you can do waveform modulation beyond the pulse width of the square wave. Because of how we have to generate the control voltages for the Curtis chip to allow for shape mod on all waveforms, it's not possible to have 50% Shape Mod equal zero modulation for the Saw, Saw-Tri and Tri and also have it give you a 50% duty cycle for the Pulse. This is a hardware matter, not a software matter.


I see what you are saying, but I disagree.

I own a Prophet 12 too and the default Basic Program wave shape for a pulse is as you'd expect it to be - square.

Either the Prophet 12's default is wrong or the Rev2's is.

For me it's the Rev2.

DSI I'm sure will put this right in a future update (fingers crossed). :)

With the Prophet 12 we were able to have 50% Shape Mod equal zero modulation for all waveforms thanks to the flexibility of the digital portion of its architecture. As stated above though, this isn't the case with the Prophet Rev2's hardware.
SEQUENTIAL