The Official Sequential/DSI Forum

Oscillator Issues

Re: Oscillator Issues
« Reply #20 on: September 01, 2017, 05:06:24 PM »
Hi Alphacode909-

While I can certainly relate to feeling frustrated as a customer, you also have a representative from the company asking you to contact their dedicated support channel to resolve any issues you may have.

Regarding anything you buy for $xxx should be perfect, I agree you can expect a professionally manufactured item to be made properly. However, mechanical and electronic items sometimes need repair and/or maintenance. Just as a BMW, Mercedes, Honda, or Ferrari require maintenance regardless of the price tag, our synths along with most any other piece of equipment you can buy are no different. Tolerances in manufacturing, wear and tear, component failure, and accidents are all bound to happen. 

Fortunately, we stand behind our products and do what it takes to make it right if something is amiss, including having the best out of warranty repair policy of any musical instrument manufacturer. I do apologize for your experience, and I encourage you to contact support if you haven't already.

We do not take issue with discussions of mechanical or electronic failures, but regardless of what the topic is, we ask that all users remain courteous and constructive when they post so it can truly be a discussion instead of purely complaint.

The title of this thread is "Oscillator Issues". If you're not talking about that, specifically on the Rev2, then your post is not on topic. Please use the search function, many of the topics you bring up have already been discussed in the appropriate threads and/or forums. If they have not, feel free to create a new topic if you'd like to discuss it.
SEQUENTIAL

Re: Oscillator Issues
« Reply #21 on: September 02, 2017, 04:13:44 AM »
I've raised it with DSI support and already had a response, which is a good start! :)

For those who asked about model and serial numbers, mine is a 16 voice and the serial is 2816-00696.


Re: Oscillator Issues
« Reply #22 on: September 02, 2017, 11:02:10 AM »
I've raised it with DSI support and already had a response, which is a good start! :)



As have I. My response was very quick and I had a good exchange with DSI tech support. They seem to be doing their job. It's an intermittent problem so I expect it may take some time to resolve. I'm feeling good about them as a company.

Re: Oscillator Issues
« Reply #23 on: September 03, 2017, 08:21:30 AM »
Considering that i posted my serial and i have an 8 voice , this issue seems to be happening to 16voices only so possibly the expansion card issue ?

Sleep of Reason

Re: Oscillator Issues
« Reply #24 on: September 03, 2017, 09:58:53 AM »
Considering that i posted my serial and i have an 8 voice , this issue seems to be happening to 16voices only so possibly the expansion card issue ?

No, mine is happening with the first four voices.

Re: Oscillator Issues
« Reply #25 on: September 04, 2017, 06:28:45 PM »
I joined the forum to comment on this topic.  I've had the Rev 2 for a couple months now.  I haven't had much time with it due to a newborn at home.  But when I did sit down to program it I immediately noticed something to similar to what is described here.  4 of 16 oscillators have weird things going on with the triangle (specifically VCO1 on my testing).   It sounds like some degree of wave folding, or hard clipping is going; I'm not exactly sure.  I contacted DSI, I sent them some recordings, etc.  I dismantled the synth a couple times haha.  I took out the expansion card, and I was still getting it.  Eventually I was shipped a new voice board but it didn't fix anything.  I spent so much time trying to troubleshoot it, that I eventually gave up.  Ha, I assume when it's sorted DSI will take care of me (I hope at least) but I felt like I was spending limited studio time trouble shooting instead of actually making music.  Mainly commenting to subscribe and see if anyone comes up with a cause and or solution.

Re: Oscillator Issues
« Reply #26 on: September 05, 2017, 05:57:52 AM »
Can you list up your serial number range and if you are in the US or abroad? Where did you purchase?

Re: Oscillator Issues
« Reply #27 on: September 05, 2017, 11:58:48 AM »
No, mine is happening with the first four voices.
[/quote]

Not necessarily when you have 2 cards in it's possible that the first voices are taken from the expansion card. It's seem strange that i am the only one with an 8 voice and have no issues.

Maybe someone could try to take out the Expansion card and see if still happening then ?

Re: Oscillator Issues
« Reply #28 on: September 05, 2017, 12:42:27 PM »
It's seem strange that i am the only one with an 8 voice and have no issues.

Maybe someone could try to take out the Expansion card and see if still happening then ?

Sinamis has already tried this.

He said...

I joined the forum to comment on this topic.  I've had the Rev 2 for a couple months now.
I dismantled the synth, I took out the expansion card and I was still getting it. 
Eventually I was shipped a new voice board but it didn't fix anything. 

I'm glad you're not experiencing any issues.
It appears the amount of problems with 16 voice models is more indicative of more people owning 16 voice models than 8 voice, rather than it pointing to the expansion board as the culprit as Sinamis post shows that removing and replacing the board has not remedied the situation.

Propheteer

Re: Oscillator Issues
« Reply #29 on: September 05, 2017, 12:43:37 PM »
I have been happily enjoying my REV2 for a while, and never really noticed this issue even though I program a lot from an init patch. Sure enough I just tested it tonight and I have this issue also (on an 8 voice!).

on triangle I have a bit of SAW on ONE of the voices but it seems to only occur over an octave from around middle C up. On pulse I have a different issue which is some of the voices are quieter than others - first 4 note strikes = even, then 3 quiet then 1 normal again.

I did try calibration, nothing changed.

I also have the 'no sound' when playing up the keybed like in the video if pulse shape is set to max, but retriggering the same key doesn't give a sound which seems weird (so not just the phase of the pulse and it's not modulated). For me to get all keys/voices to sound I have to back off the shape mod a little (from fully clockwise) which suggests that in my case ONE voice when on max shape mod is going into full PW cancellation while the others aren't, so each voice is slightly off. Knowing this and backing off shape mod a bit isn't really too big a deal, afterall voices cancel out on some PWM synths when you put them to max (when the waveform collapses), the issue is that not all of them are doing it here and calibrating doesn't make them follow the same settings. In normal use I'd rarely be on full shape mod on triangle or pulse waves though it could hit it via modulation.

Same on triangle, the 'bit of saw' seems related to shape mod. the same voice/note that acts up in pulse is also the one acting up on triangle (when shape mod is at minimum). So in triangle/basic program init (shape mode zero) any out of calibration voices will have a bit of 'saw', and with pulse that same voice when shape mod is at max will have a collapsed wave (no sound). Not sure if this will help anyone or DSI to pinpoint if something can be done in software but it seems it's a calibration issue outside of the power of the built in calibration menu (so a FW fix may update the calibration routine to correct for this shape mod issue on random voices?)

Gotta say these issues do seem a bit off for a brand new synth, the funny thing is I've been making some great patches that these issues are not part of at all because they seem to be extreme cases of specific uses of waveforms/shape. Though I can see the triangle or fully shaped pulse being an issue if you want pure triangles across all notes (as you should).

Furthermore if this becomes a legendary fault like the Sub37 filter pot issue, it could affect resale value down the line "hey does yours play ok on triangle/pulse on all notes?". If this is an issue I'd like DSI to tell us upfront so we can return to the retailer (those of us who still have the chance)

So, yeah an 8 voice here with issues, that didn't affect me in normal use but do bug me now I know they are there because they feel like faults and could rear their head later on in life under certain sounds.
« Last Edit: September 05, 2017, 12:58:03 PM by Propheteer »

Propheteer

Re: Oscillator Issues
« Reply #30 on: September 05, 2017, 01:36:43 PM »
Can confirm i don't have that issue on my 8 voice version. Serial 2808-006xx .

I have the issue on one voice (as above) and I'm in the 600 serial range (first part is just 8 or 16 voice model code it seems), I'm also on 8 voice - 2808-006xx

On a pure triangle patch I just tried, soft single osc sound, it clearly can be an issue when that one voice pipes up! so needs fixing. The fact you don't have the issue means it is a mis-calibration on some units or bad shape mod pots calibration or something else. DSI need to answer on this if they can fix this in software or I may have to return it within my time limit. :( sadly because I love the synth but probably wouldn't get a replacement if this is the case and no word from DSI on fixing or why it does this.
« Last Edit: September 05, 2017, 01:39:24 PM by Propheteer »

Re: Oscillator Issues
« Reply #31 on: September 05, 2017, 03:36:14 PM »
Can you list up your serial number range and if you are in the US or abroad? Where did you purchase?

I'm in the US and I purchased from Detroit Modular.  I received one of the first units they had.  2816-001** is the SN.  So that must make it one of the first 100s I guess?

Re: Oscillator Issues
« Reply #32 on: September 05, 2017, 05:27:24 PM »
I'm being assisted by DSI to try and work out the problem, but I'm tempted to return for a refund whilst I still have the time to.

Really conflicted as in every other way I really, really like this synth.

After further investigation, here’s what I now know for certain…

1: This problem only occurs on oscillator 1, oscillator 2 seems to behave as expected.

2: it only happens on keys to the left of Middle C.

3: With the triangle shape selected the further down the keyboard you move, the more pronounced and dominant the erroneous sound is.

4: On a pulse wave shape Mod to 50% to be square, the problem is exacerbated to the point that certain notes don’t sound at all.

5: The pulse wave notes that don’t sound seem to be D3, D♭, B♭, G2, and D1.

6: And this is the big one…It seems to happen on every 16th note. By that I mean that if I repeatedly play any of the affected notes, the symptom will show itself on the 16th press of the key.

I’ve uploaded another video which more clearly shows the issues which can be viewed by clicking the link below.

https://www.youtube.com/watch?v=8ZaYN5lVmP4&feature=youtu.be

PS: This happens on the effected keys whenever I have played 16 notes, so I do not have to play the same note repeatedly to produce the fault. I could for example play a 15 note solo on the upper part of the synth and if the 16th note I press is one of the lower effected keys it wouldn't sound/sound incorrectly.
So this issue has 'real world' implications and genuinely affects the playability, this isn't as issue that only occurs when the same note is played 16 consecutive times and if it was then it wouldn't be a problem.
« Last Edit: September 05, 2017, 06:06:02 PM by jazzygb1 »

Sleep of Reason

Re: Oscillator Issues
« Reply #33 on: September 05, 2017, 07:01:35 PM »
Not necessarily when you have 2 cards in it's possible that the first voices are taken from the expansion card.

Well I suppose you could assume that I hadn't checked under the hood.  ;)

Propheteer

Re: Oscillator Issues
« Reply #34 on: September 05, 2017, 10:09:49 PM »
I'm being assisted by DSI to try and work out the problem, but I'm tempted to return for a refund whilst I still have the time to.

Really conflicted as in every other way I really, really like this synth.

After further investigation, here’s what I now know for certain…

1: This problem only occurs on oscillator 1, oscillator 2 seems to behave as expected.

2: it only happens on keys to the left of Middle C.

3: With the triangle shape selected the further down the keyboard you move, the more pronounced and dominant the erroneous sound is.

4: On a pulse wave shape Mod to 50% to be square, the problem is exacerbated to the point that certain notes don’t sound at all.

5: The pulse wave notes that don’t sound seem to be D3, D♭, B♭, G2, and D1.

6: And this is the big one…It seems to happen on every 16th note. By that I mean that if I repeatedly play any of the affected notes, the symptom will show itself on the 16th press of the key.

I’ve uploaded another video which more clearly shows the issues which can be viewed by clicking the link below.

https://www.youtube.com/watch?v=8ZaYN5lVmP4&feature=youtu.be

PS: This happens on the effected keys whenever I have played 16 notes, so I do not have to play the same note repeatedly to produce the fault. I could for example play a 15 note solo on the upper part of the synth and if the 16th note I press is one of the lower effected keys it wouldn't sound/sound incorrectly.
So this issue has 'real world' implications and genuinely affects the playability, this isn't as issue that only occurs when the same note is played 16 consecutive times and if it was then it wouldn't be a problem.

Let us know what they say (i.e if it's definitely a defect) as many of us with this issue are also within the return window and obviously it would be easier to return than have to mess around with new boards being sent out (mainboards/voiceboards) from the US (to the UK here) trying to troubleshoot this. Like you I really like the synth so it's a shame if so. I don't seem to have it as bad as you so can't work out why different units have different issues (even as analog synths) as these boards should all be pretty much within the same tolerance and gremlin level unless there's some real electronic faults on some of them (SMT caps blown etc).

DSI should come in and put our minds to rest if they can on if they know of this issue and if it affects all REV2s or just some unlucky ones.

Propheteer

Re: Oscillator Issues
« Reply #35 on: September 05, 2017, 11:57:43 PM »
Actually testing it again this morning, mine definitely doesn't seem as bad as yours even while having issues. For example my pulse wave not playing on certain notes is only if I have shape mod far right not at 50% - at 50% all notes play and all voices play (retriggering a key 8 times). I can live with the wave collapsing on just one note at the extreme as I'd probably never use that (esp on its own where you can hear it), the other little faults (volume differences on pulse/tri on osc 1 only 4 voice) are not too in your face and probably add a bit to the liveliness.. 'real analog' feel ;). And that one remaining issue - the ONE voice on triangle osc 1 only that has a bit of square in it is the only real issue that could rear its head for me, if I was using a pure triangle patch it renders it useless so would definitely like to see a fix for that.


Gerry Havinga

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Re: Oscillator Issues
« Reply #36 on: September 06, 2017, 12:37:01 AM »
I'm being assisted by DSI to try and work out the problem, but I'm tempted to return for a refund whilst I still have the time to.

Really conflicted as in every other way I really, really like this synth.

After further investigation, here’s what I now know for certain…

1: This problem only occurs on oscillator 1, oscillator 2 seems to behave as expected.

2: it only happens on keys to the left of Middle C.

3: With the triangle shape selected the further down the keyboard you move, the more pronounced and dominant the erroneous sound is.

4: On a pulse wave shape Mod to 50% to be square, the problem is exacerbated to the point that certain notes don’t sound at all.

5: The pulse wave notes that don’t sound seem to be D3, D♭, B♭, G2, and D1.

6: And this is the big one…It seems to happen on every 16th note. By that I mean that if I repeatedly play any of the affected notes, the symptom will show itself on the 16th press of the key.

I’ve uploaded another video which more clearly shows the issues which can be viewed by clicking the link below.

https://www.youtube.com/watch?v=8ZaYN5lVmP4&feature=youtu.be

PS: This happens on the effected keys whenever I have played 16 notes, so I do not have to play the same note repeatedly to produce the fault. I could for example play a 15 note solo on the upper part of the synth and if the 16th note I press is one of the lower effected keys it wouldn't sound/sound incorrectly.
So this issue has 'real world' implications and genuinely affects the playability, this isn't as issue that only occurs when the same note is played 16 consecutive times and if it was then it wouldn't be a problem.
Excellent description of the problem, great troubleshooting skills, thank you very much.

I tested this on my Rev2 (8 voice), serial 2808-004xx and I cannot reproduce it. I am on the latest firmware, system is stable and responds correctly. Being able to consistently reproduce the fault, in your case, on the 16th value makes me believe this is some kind of register overflow issue (2^^16). Which might mean DSI could fix it or create a workaround in the firmware possibly. Obviously this is a speculation from my side.
DAW-less and going down the Eurorack rabbit hole.

Re: Oscillator Issues
« Reply #37 on: September 06, 2017, 06:21:48 AM »
Ive got a higher serial number 16 voice (587). I'd like to attempt to reproduce this so pardon my ignorance in my next question.

Can you cats SPECIFICALLY state what you are doing and/or how to exactly reproduce?

Is this from an init patch or is this with any patch using a pulse?

And this "concern" should occur every 16th played note yes?

Re: Oscillator Issues
« Reply #38 on: September 06, 2017, 07:22:44 AM »
Ive got a higher serial number 16 voice (587). I'd like to attempt to reproduce this so pardon my ignorance in my next question.

Can you cats SPECIFICALLY state what you are doing and/or how to exactly reproduce?

Is this from an init patch or is this with any patch using a pulse?

And this "concern" should occur every 16th played note yes?

To be honest I think I'd already been very specific!!!

I've explained it clearly in my previous post and then did a video too!

How much more specific do you want? lol

Anyway, as demonstrated in the video... I started from a new Basic Program, selected just oscillator 1 (Osc mix knob hard left) and (in my case at least) the issue occurs as demonstrated with only the keys only in the lower octaves affected.

Basically for the keys effected this what happens...

With a triangle shape selected on the oscillator, the 16th press will always sound a louder sawtooth kind of sound.

With a Pulse selected on the oscillator and put in square wave (50% shape mod), the 16th note played will always either play a sawtooth or not sound at all.

I must stress this issue occurs EVERY 16th note for me, regardless of what 15 keys were played before.
You do not have to play the same note 16 times for it to occur, I only play the same note 16 times in the video to clearly illustrate the pattern.

For example if I played 15 notes in the higher octave and then played a 16th note in the 'effected zone' in the lower octave, the same wrong sound/no sound fault would occur.

So this is a problem that actually manifest itself in 'real world' playing too.

Obviously the likelihood of playing the same note 16 times in a row in a song are quite slim and if this was what you had to do for the issue to occur, then I'd probably not be bothered about it.

However the 16th note is ALWAYS affected if it's an effected note, regardless of where the 15 notes preceding it were played if you understand and that's why it's a problem.

That's my issues in a nutshell, other users experiencing issues may have slightly different symptoms.

I'll upload another video later to further clarify what I mean.
« Last Edit: September 06, 2017, 08:03:19 AM by jazzygb1 »

Propheteer

Re: Oscillator Issues
« Reply #39 on: September 06, 2017, 07:57:58 AM »
Bear in mind your issue may not be exactly like Jazzy's, you could still have an issue like me (even on 8 voice) on just one voice rather than all 4, or maybe on 2,3 or 6.. your synth might be different.

He did go into a lot of detail already imo.

Init a basic program, this will only use OSC 1, set it to triangle, play the same key over and over till you've gone through all your voices (8 or 16) and listen for anything other than a pure triangle (a bit of buzz/square as if shape mod is changed for that voice only). That is one issue. Also that MAY only occur on certain ranges of keys so try playing that init sound on triangle up and down the keyboard.

Change it to pulse waveform and set shape mod to 50% - repeat above.

CHange shape mod to full clockwise - repeat above (this is an issue I have but jazzy doesn't I think) - where ONE note (same one as bad triangle) is silent because that full shape mod has collapsed the wave (out of calibration) vs the other voices.

It's always the same voice when you have an issue and the voices play in a cycle.

This DSI silence is a bit worrying... All I'd like to know if this weirdness is as 'designed' and all REV2s have it, or if I have a genuinely faulty unit that I have mere days to return!! :(
« Last Edit: September 06, 2017, 08:07:20 AM by Propheteer »