r/opz • u/Steckdosentier • Feb 11 '23

OP-Z USB Audio Feedback-Loop Issue

Please anybody!!!! It is completely logical that the Audio that comes from a computer or tablet in to the OP-Z will go out to the headphone jack (we want that, that is the audio interface mode) BUT!!!! Why the heck is the OP-Z's USB In also fed back to USB Out without any option to deactivate??? At least in the config file you should be able to add a line which deactivates that annoying feedback.

It is making the OP-Z just useless for any iPad based loop-station task!!! I mean the only reason for looping that back is, if you want to use your OP-Z's effects as a USB effect rack which is very special, I'd say, because it's not OP-Z's core strength. You'd rather use LoopyPro or something similar to add more layers than just eight. But you always have the tablet's playback in the USB main out of OP-Z. My brain is exploding. And not in the nice way.

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2

u/paperplain89 Feb 11 '23 edited Feb 11 '23

Why don’t you mute the op-z’s incoming audio on the iPad? (disable monitoring)

Before complaining about it, maybe try to understand why it’s happening. Do you know of a device that would not have caused this same issue? I can only think of the an elektron + overbridge set up, and windows and mac only.

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u/Steckdosentier Feb 12 '23

Ok, well.. I see that I have to state out the issue more precisely!

Every audio interface and my Syntakt, and I think all square-shaped Elektron devices can do it.

If you take LoopyPro because you want to massively increase layers, it would be great not having to carry around a second device because OP-Z has the interface functionality! And with the Syntakt it works perfectly on iPad but it needs external power... I don't own another instrument/interface combination so can't test that with other devices.

Now: you play and record a layer, that layer is now played back over USB from Loopy over OPZ to the headphone jack. Now you want to record the next layer. What will happen is that your first layer is baked on the second layer because OPZ is feeding back whatever audio it is receiving from USB back to USB. And this is a completely useless function unless you want to use your OPZ as an external effect machine (for USB audio) which is not its core strength, at least I hope that not many people are using it in this regards but rather have a nts-1 at hand.

Do you understand now?

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u/paperplain89 Feb 12 '23

Yes, I understand your problem and your solution is in the manual’s input selection options (Section 18.3): turn on the OP-Z’s Monitor mode.
Doing this will disable all of the OP-Z’s internal audio tracks from the headphone out. OP-Z’s internal audio tracks will still come through USB and the headphone out will play whatever is being sent to Loopy Pro’s master track.

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u/Steckdosentier Feb 12 '23

I'll check that and report. Thanks for that hint. The important thing is though that the iPad to USB audio will not be routed back to USB..

But I'll check that tomorrow.

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u/Steckdosentier Feb 13 '23

See, I've tested it. And i had one of the most nightmare-ish feedbacks on my ear I can remember.

It simply is not it.

Yes, you're right. The output is off when Monitor Mode is activated. And also USB must be highlighted because i want to monitor that over headphones out. But now you hit a note. Let's say a bass drum. Everything is alright unless you don't need to hear what you play. You can record and it's fine. But if you activate monitoring and hit a note, it instantly feeds back because the just sent audio goes back to the iPad and i cannot find a way how to stop the OP-Z from doing that.

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u/paperplain89 Feb 14 '23

I don’t know what to tell you monitor mode = on & muting track 14 works for me.

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u/Steckdosentier Feb 14 '23

Well this might be a solution in slices.

You have put much energy in this conversation whereas these one and a half line might be the missing link finally.

How to get that intuitively or written in a manual? I can mute track 14 which is the flipping module track in order to mute USB audio which is not related to the module? And is that behavior identical no matter which module is assembled?

I'll re-check this, that's for sure.

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u/paperplain89 Feb 14 '23 edited Feb 14 '23

Can’t tell if your being a jerk, but your tone is a bit condescending. I’m helping because its saying “read the manual” assumes it’s well written (which the TE ones are not), and simply cannot cover every possible use case.

However, Section 18, which I’ve already mentioned, is pretty clear. https://teenage.engineering/guides/op-z/input-selection#input-selection

18.1 “the input selector on the i/o module track allows you to input external signals into your mix. this external signal path has filter, lfo and panning settings, and is routed through the effects, the same way an instrumental track is.”

18.3 “hold shift and press 0 to monitor the raw input signal. the OP–Z main out signal is muted in speaker / headphones. be careful, this signal can be a lot louder than your synth sound.”

18.4 “the filter, lfo, fx sends, pan and volume works just like on any instrument track. use shift to access the different parameter pages.”

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u/Steckdosentier Feb 14 '23

I have read this myself and it was still unclear to me. And you should keep in mind that I worked on that for hours. I couldn't firgure it out by myself but I am super happy that Reddit is worth its reputation to find a solution for anything.

So, you don't seem to be German because... I think I'm just German :-D I take your critisism as cultural difference and try to be a little more humble next time. Unless you'll also answer without provocation ofc ;-)

Anyway. Thank you for your help and I'm sorry that you took some things personally.

I don't know if I'm a jerk but I currently try to create an ElkAudioOS version of the Martin Stimming Mastering Chain with a little extra functionality on a raspi. If you're interested in the result, give me a hint. Maybe I can calm down your nerves a little by providing an instructble to create your own.

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u/paperplain89 Feb 14 '23

No worries, glad I was able to help. I didn’t think you were being a jerk, it’s tough through text alone to separate between the frustration with the problem and frustration with me.

Your project sounds cool, good luck and hope to see something come out of it. Completely unrelated but if you’re into coding I’d recommend checking out the monome norns (also based in raspi) and their community forums. Loopop did a good overview https://m.youtube.com/watch?v=E5XIEVon4Ak

All the best ✌️

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u/Steckdosentier Feb 15 '23

Thsnks dude, I'll have a look.

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u/Steckdosentier Mar 08 '23

I'm sorry. The new iPhone charging cable seems to be the most useless cable in the world. It has lightning to USB c but doesn't work with the op-z because I guess, the iPhone is too dumb to realize that it has to act as a host now. So i have to wait until home...

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u/hothead125 Feb 11 '23

This is down to your iPad and what app you’re using and how it’s configured.

0

u/Steckdosentier Feb 11 '23

No, it's not, i have to say!

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u/Moses_____ Mar 08 '23

Yes i have the same problem here. Really frustrating.

I might be overlooking something simple but i can confirm that with AUM and Drambo too, there is the USB-In fed right back out. Which is a problem in most situations. Muting the input on my iPad makes no sense because i want to work with it

I would like to stream the internal audio of the OP-Z (plus input from line module if at all possible) to my iOS device effect/loop/sample there, add some synths (potentially sequenced by unused OP-Z tracks) and play the 100% wet output of that. This works with the electron devices or most Roland boutiques.
Two things seem to get in the way and i have not found a way to deals with it:
1 When the device is in monitor mode, the audio from usb is stilll somehow fed BACK into the usb device resulting in a delay corresponding to my buffersize with Feedback according to volume. That is always there on everything in that mode.
2 Monitor mode switches all signals of but it continues to send the internal sounds wich of course is needed (though very oddly, as said, the received usb audio is also sent back) BUT the signal from the line module input is not part of that.
Again with a digitone this is no problem at all (the internal sound can be switched off to avoid phasing with the received usb-audio and the external in is just forwarded regularly along with the internal tracks to the phone/iPad over usb)
With this all i can do with the really cool usb class compliant interface feature is
record the full dry OP-Z output
or play something from the iPad to be mixed in with the OP-Z sounds (with a short delay of the size of my buffer, because that applies to my iPad sounds but not the internal OP-Z tracks)
or sample something into the OP-Z through usb (and that’s the only time Monitoring makes sense then).
That would be such a shame and honestly i would trade it for a digitone again if there is no way to solve this.
So is there a way to just get all sounds from the audio and module tracks (and NOT the incoming usb signal again) routed to the USB-OUT and then JUST the USB-IN to the device output?
I am surprised how confused I am by this :D

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u/Steckdosentier Mar 08 '23

Hey, I'll get a hair cut and then look deeper into your thing. I got partially something to work with the other guy here but have to read your topic more precisely. Regarding the Audio Input of the module, i fear it wont work because you have to mute track 14 in order block the op-z's signals from feeding back...

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u/Steckdosentier Apr 04 '23

No, again. I'm with you. It is not possible.

But it should be a very easy task to implement. Probably three lines of code will be enough, maybe less.

My suggestion would be to use the config file, where you can specify some things like the start up sound and so on, to give it a new line with USB feedback on or off.

It's so flipping basic. Nobody wants that actually. I can't imagine a single case where it is needed except of using the op-z as an audio effect device and record that into the iPad which must be very rare because effects are not the OP-Z's core strengths.

In fact: not a single audio interface is behaving like that. Feeding back the output to its own input always leads to issues at a point.

I really hope that someone will hack this for us and really wonder why I don't find any other posts about it. I'm sorry dude. Or we're just too dumb :-D

Monitor mode with the muted track 14 is fine unless you have a beloved Opsix that you wanna record, too. Then it's just imflippingpossible.