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micro delay for midi or audio ?

Posted: Mon Jan 04, 2021 10:41 am
by nebelfuerst
In my setup there are HW-synths, scope-synths and VSTs. The VSTs might be on a different computer than scope. ( connected by Adat )
All connections cause some latency, which I want to compensate somehow.

One idea would be to delay each midichannel with a different delay.
An other idea would be to delay the incoming audio stream at the scope mixer.

( I don't want to use the delay function of a DAW.)
Does any solution for this delays already exist ?

Re: micro delay for midi or audio ?

Posted: Mon Jan 04, 2021 11:07 am
by valis
I know the general practices used in my DAW for doing sample-based testing and record delay compensation (by hand), but I haven't considered this with Scope as the central player to day (I mix where I record, in software). There was once an excellent discussion of this with Cubase & Logic as the centerpiece, but that's gone by the wayside it seems so all I see now are forum threads like this: https://www.gearslutz.com/board/apple-l ... issue.html

Note that he's inputting a delay in a Logic preference setting that will shift all recorded audio to be sample-accurate in regards to audio that originates in Logic. What isn't stated in that thread is that you also have a perceptual shift when 'playing alongside' audio coming out of the DAW, and this same procedure can be used there.

We can 'delay' things in Scope by actually delaying the audio as it passes through. Phasefix-X from Assaf was created to compensate for small variations, though it's use was intended to fix devices that are not phase coherent between left & right channels when the signal exits a (non-dsp locked) device. This tool can also perhaps be used for small variations.

For larger variations, a normal delay plugin with 100% wet and NO other processing might work, but you will need to verify the one chosen is 100% distortion free (no alteration or coloration).

And you will likely need to handle each signal path or piece of gear etc as its own entity when doing this. Dawman & others can tell you how to ensure that when you reload a project these relationships stay on the same DSPs that your originally created project used, so that these values do not change dramatically *within scope*. That does not mean however that values in other devices (or a VST stack on another computer) will not change. So you might need a workflow that accounts for checking this before and/or while working.

Re: micro delay for midi or audio ?

Posted: Mon Jan 04, 2021 11:20 am
by fra77x2
of course there are dsp delays that can be used to control delay of audio signals with 1 sample accuracy

Re: micro delay for midi or audio ?

Posted: Tue Jan 05, 2021 4:11 pm
by astroman
The standard 2448 Mixer has such a delay (in sample increments) per channel... ;)

Re: micro delay for midi or audio ?

Posted: Tue Jan 05, 2021 4:43 pm
by valis
astroman wrote: Tue Jan 05, 2021 4:11 pm The standard 2448 Mixer has such a delay (in sample increments) per channel... ;)
:)

Re: micro delay for midi or audio ?

Posted: Wed Jan 06, 2021 12:10 pm
by nebelfuerst
The ( newly learned ) delay function in 2448 mixer can do a max of 200 samples.
If I calculate the max delay 1/48000*200 = 4.1ms.

My problem is, that the delay from the VST-Adat-path is in the order above 6ms. ( The buffer of the RME-digi96 can go down to 256 samples, not less.)

Is there a "larger fifo" available easily ?

Re: micro delay for midi or audio ?

Posted: Wed Jan 06, 2021 12:18 pm
by fra77x2
in the sdk there are dsp lines with several sizes. 200, 800, 1k, 2k, 2.9k. these can be connected in series to get bigger sizes. Each dsp has its own dsp memory i think each provides around 7k of dsp memory. Perhaps someone with the sdk can upload some

Re: micro delay for midi or audio ?

Posted: Wed Jan 06, 2021 1:34 pm
by yayajohn
Found this you can try. Don't know where It's from or who made it.
(anyone objects to sharing this please let me know and I'll remove)

Re: micro delay for midi or audio ?

Posted: Fri Jan 15, 2021 9:20 am
by nebelfuerst
As I was quite busy, I didn't find the time to try this yet.
Nevertheless I should say "thanks" for your replies.

Re: micro delay for midi or audio ?

Posted: Thu Jan 28, 2021 12:00 pm
by nebelfuerst
Dies Milli-Delay work with scope7 ?
I can use it as insert, but I don't get a gui to change any settings.
What's wrong ?

Re: micro delay for midi or audio ?

Posted: Wed Apr 14, 2021 12:14 pm
by Spielraum
nebelfuerst wrote: Thu Jan 28, 2021 12:00 pm What's wrong ?
check rework `21
viewtopic.php?f=16&p=348966#p348966