[SOLVED] certain scope synths and modules causing stuttering while modulating midi

[scopus]

hey friends, been revisiting my scope cards after a long break and noticing a very unusual issue i cant figure out.

After some testing im finding its happening on some synths and modular modules but not all. For instance it happens on inferno, ez synth, flexor. But doesnt happen on minimax, profit 5, modular3 stock filters.

Often i assign a modwheel or knob on my midi controller to modulate the cutoff on a synths filter. When i play with controller and modulate the filter cutoff i hear stuttering while i modulate it on the problematic devices i listed above. this only happens when using the midi controller, if i modulate the knob with my mouse there is no stuttering. Also i dont notice any latency while playing keys on the midi controller, this is just while modulating the knob. Ive tried different latency settings, including lowest no help. I have 2 cards installed tried midi input on both cards no help. Heres 2 sound examples on one of the above problematic synths, one modulating with mouse which is smooth, than with midi controller can hear the stuttering im talking about.
Any ideas?

https://soundcloud.com/metamorphosis321 ... al_sharing

windows 7
scope v5.1.2709-x64
scope home card and scope pro card (18dsp total)

[astroman]

I just tried it on Scope 5.1, Win7/32 with same result on Inferno.
No problem with a Flexor LP4 Legend filter in Mod2 shell (as the only module of the patch). Flexor is version 3.

Iirc ages ago there was an optimization of parameter control (interpolation against stepping).
Maybe the midi section of some devices was missed and only the mouse GUI was updated.

[valis]

This was once normal behavior even on regular synths. Midi is 0-127, so if you want to sweep a filter that's a big step between positions. Assigning a higher value controller (pitbchbend is 14bit for instance) on devices that allowed this was one workaround, similarly using an envelope or LFO with delayed start ...etc.

Slew limiters do this in the modular world, but note in the digital realm this always adds a small bit of latency to the responsiveness.

[Bud Weiser]

... midi controller stuttering ...


https://soundcloud.com/metamorphosis321 ... al_sharing

windows 7
scope v5.1.2709-x64
scope home card and scope pro card (18dsp total)

also @valis,-

the stuttering sound while sweeping the filter cutoff is way more than the usual "MIDI zipper noise" we got/get from ancient midified hardware synths and midi-modules.
I still have many here and that´s by far not the same.

MIDI CC assignment and total recall as also controller resolution and MIDI clock related timing need much more care in Scope.
It´s all old protocol from 80s/90s and simply should work as good as other MIDI devices do.
Doesn´t mean NO zipper nois, but this is way too much.

It should be reported as a bug and being forwared to SC support.



Bud

[valis]

Understood, will confess I am packing and can’t fire up the old synths to see what this issue is. Please report the big.

[Bud Weiser]

... Please report the big.

Scopus, the original poster, should do.
It´s his audio demo and his setup.



Bud

[valis]

Of course, do I come across as that bossy right now? Apologies, moving and only on mobile.

[scopus]

I just tried it on Scope 5.1, Win7/32 with same result on Inferno.
No problem with a Flexor LP4 Legend filter in Mod2 shell (as the only module of the patch). Flexor is version 3.

Iirc ages ago there was an optimization of parameter control (interpolation against stepping).
Maybe the midi section of some devices was missed and only the mouse GUI was updated.

interesting you also notice on inferno the issue, so i guess might indeed be a bug on certain scope synths which i didnt use in past so wasnt aware of. Flexor tho i used to use all the time and was smooth before while sweeping filters within patches, and im noticing the issue now on most filters including lp4 legend. Just remembered this pc is a kinna recent install. Will do a little more testing by installing cards back onto my old computer and another midi controller and report back.
Thanks

[scopus]

im about giving up on this, tried everything i can think of trying to rid of the stuttering while modulating flexor filters with midi
tried diff computer, midi controller, midi cable, midi input on secondary card, diff windows and scope versions...

Most of the time its not as bad as first audio examples, but mostly always is like this no matter what i tried:


https://soundcloud.com/metamorphosis321 ... al_sharing

as can hear on a very simple modular patch while controlling cutoff via midi, it sounds like a purr. cant get it smooth like on mouse.

attached here the modular patch and audio mp3's be much appreciated if someone with flexor can test to see if get same results as me.

Only thing i can think of is perhaps my main pci card is causing or more likely its always been like this and i just didnt notice in the past. Again this is only on some devices not all. Most flexor filters its happing (lp-1/4/8, bp-1/4/8....) but doesnt happen on stock modular filters, most scope synths except the ones i listed...flexor is my main work horse tho so really wish could find a solution

Any ideas, or workarounds to be able to control a flexor filter knob smoothly?

[astroman]

Sorry for missing this detail, but it should have been obvious from your original post already:
you do the control via a hardware dial and in that case the midi transmission line has to considered, too
Cable whip connection and opto-coupler on board, iirc I‘ve had fails on both, very few over the years, but it happened.
Your hint to 1 specific card points in this direction. Can you place the cable on another card or swap whips ?

[scopus]

Sorry for missing this detail, but it should have been obvious from your original post already:
you do the control via a hardware dial and in that case the midi transmission line has to considered, too
Cable whip connection and opto-coupler on board, iirc I‘ve had fails on both, very few over the years, but it happened.
Your hint to 1 specific card points in this direction. Can you place the cable on another card or swap whips ?

got 1 scope pro card with all my keys and 1 home card and tried both via the whip on pro card and on the home card midi adapters, so likely not that. Also tried different midi cables, bought a new midi keyboard for this and tried via its usb connection as well same issue. And tried many other things like different computer, both 32 and 64 bit windows, older scope 4.0...

Only thing can think of is perhaps something on my scope pro card is faulty. Cant test home card by itself since all my keys on the pro. Or the other possibility is this issue exists for everyone and i somehow didnt notice in the past.

if could please test attached file, see if get similar results while modulating the filters cutoff with like a mod wheel and compare with controlling via mouse
be much apricated

thanks

[st1]

Only thing can think of is perhaps something on my scope pro card is faulty. Cant test home card by itself since all my keys on the pro. Or the other possibility is this issue exists for everyone and i somehow didnt notice in the past.

I acknowledge that I have not tried to reproduce the problem, so this is pure speculation.

But I have at least one board where the capacitor dry-out manifested itself initially as "MIDI-problems".
Further investigation proved that it also induced audio-crackles, but this was less noticable due to one or two samples being garbled every now and then.
But the MIDI-issue was hanging tones, non-triggered tones tec.
I also found that one board will affect the behaviour of other boards (e.g. failing caps on one card would affect the output of another card in the same machine - I am guessing because the distribution of processing across DSPs).

Of course, it could "just" be also be a software issue.
All software has bugs, as well as "wasn't designed for this particualr use case" situations.

But, just maybe, your board could be approaching (just on the verge of) suffering from "bad-cap" illness.
Difficult to say how to diagnose this - but do you have any sense of crackling audio or simliar?

[scopus]

Only thing can think of is perhaps something on my scope pro card is faulty. Cant test home card by itself since all my keys on the pro. Or the other possibility is this issue exists for everyone and i somehow didnt notice in the past.

I acknowledge that I have not tried to reproduce the problem, so this is pure speculation.

But I have at least one board where the capacitor dry-out manifested itself initially as "MIDI-problems".
Further investigation proved that it also induced audio-crackles, but this was less noticable due to one or two samples being garbled every now and then.
But the MIDI-issue was hanging tones, non-triggered tones tec.
I also found that one board will affect the behaviour of other boards (e.g. failing caps on one card would affect the output of another card in the same machine - I am guessing because the distribution of processing across DSPs).

Of course, it could "just" be also be a software issue.
All software has bugs, as well as "wasn't designed for this particualr use case" situations.

But, just maybe, your board could be approaching (just on the verge of) suffering from "bad-cap" illness.
Difficult to say how to diagnose this - but do you have any sense of crackling audio or simliar?

yh quite possible is a hardware issue as its a very old card. regarding audio, currently not noticing any issues, just this "purr" i get while modulating various filters via midi. Most the time it "purrs" like in latest example or sometimes the filter gets sort of stuck and stutters very badly like in first example and i have reload it, but no matter what its not smooth. Could be bugs or hardware, indeed a difficult thing to diagnose
thanks

[djmicron]

Hi, I can confirm that behavior.
As workaround for the modular, you can use the Constant value module and connect it to the Cutoff modulation input, then set the modulation amount to maximum and assign the midi controller of your choice to the Constant value slider.
I attached the modified patch.
About the other synths, it could be possible with SDK to fix something if I remember right, the Inferno and some of the basic synths can be reverse engineered from the SDK project explorer.

[valis]

Didn’t somebody make a modular patch that again outputs MIDI so you can use Constant Val to adjust other synths? Or was I mistaken?

[djmicron]

Didn’t somebody make a modular patch that again outputs MIDI so you can use Constant Val to adjust other synths? Or was I mistaken?

you mean sending the cc message from the Control value to the modular midi out?
It doesn't solve the problem, it only works by using the integer signal out and for example, the Inferno synth doesn't have a modulation input for that purpose and sending midi cc internally to Scope doesn't solve the problem.
That kind of problem must be solved on the buggy device.

[scopus]

Hi, I can confirm that behavior.
As workaround for the modular, you can use the Constant value module and connect it to the Cutoff modulation input, then set the modulation amount to maximum and assign the midi controller of your choice to the Constant value slider.
I attached the modified patch.
About the other synths, it could be possible with SDK to fix something if I remember right, the Inferno and some of the basic synths can be reverse engineered from the SDK project explorer.

Djmircron Your a king! flexor problem solved Glad my card is ok and will use this workaround from now on,
About the scope synths guess they are indeed bugs, will report

Thanks so much!!

[valis]

I am sure Speilraum demonstrated a way to get stems this, but you may be right he often digs into devices and improves them so that may have been part of the fix.

[djmicron]

I am sure Speilraum demonstrated a way to get stems this, but you may be right he often digs into devices and improves them so that may have been part of the fix.

I have tried it before answering, it looks like the glitches are caused by the lack of interpolation on the receiving parameter.

[valis]

That’s what I mentioned above.