1 (edited by TR62 2019-07-16 03:23:04)

Topic: Ableton UFX buffer corruption when editing MIDI

Hi Guys

Hope you can help.  I have a lot of programming to do, and keep hitting a strange behaviour when using a UFX with Ableton.

The setup is an 8core i7 with Asus mobo, Win10, an Orico USB 3 powered hub, and plugins from Toontrack and Spectrasonics.  The Orico hub has proved stable on other machines.  I have sample buffers set to 96 samples and it's fine at 48kHz.

So it's perfect when you treat Ableton as a host only, and use an external sequencer.  No issues.  But record that MIDI into Ableton to edit visually, and the buffers get scrambled when you move note events.  The only way to get it back is to change the sample rate of the driver, from 48kHz to 44.1kHz and back, which clears it. 

Is anyone else experiencing this kind of oddness?  I can edit MIDI all day if not using plugins, but try to use plugins and I get very odd results.  Playback is flawless.  The error count in the RME driver increments when this happens, to things like 0/34 (what on earth does this actually tell me!?).  Latest driver installed.

The Novation Launchpad is in the hub too.   That is losing connectivity quite regularly too, demanding an insertion event.  I did recently activate the MMCSS option in the driver.   Can't imagine that messing with it.  Ableton is v9.7.7.  I could link the plugins via Ensemble if this would help.

I have read that the Orico hubs use VIA USB 3 chips.

We have a Jetway built PC here with an Orico and do not experience these issues.  I have several hubs to swap between too.

If anything here sounds familiar, please chime in.  I'd love to get to the bottom of it.  I can work, but the fun has gone from editing.  Feels like I am fighting it, rather than flowing with it.

Thanks in advance.

2

Re: Ableton UFX buffer corruption when editing MIDI

You have a basic USB performance problem on the port that you currently use. Try other ports.

Regards
Matthias Carstens
RME

3 (edited by TR62 2019-07-16 11:24:42)

Re: Ableton UFX buffer corruption when editing MIDI

Hello Matthias,

The Orico is USB3, connected to a USB3 port on the back of the PC (a motherboard port), so I am not sure the bottleneck is upstream.  All other ports are the same standard on both devices. 

So could this point to other devices in the hub?  I have the UFX, an ESI 4x4 MIDI device (USB2 I believe), a Sandisk Cruzer (a licensing dongle), and the Launchpad S.  Cables are all new, and I believe good. 

Using a hub with a 2Amp PSU to get the distance over USB3 (rack to rack connection).  They are within spec for distance (3m).

I'll rearrange the space to bring things closer together, and will experiment with choice of motherboard port, and shorter runs and see how it goes.

Re: Ableton UFX buffer corruption when editing MIDI

Update.  Shortened the cable to 2m between the hub and UFX and it improved the "Errors: 0/nn" rate of change, downwards.  I am getting to about 0/24 in half an hour or so, which I can live with while editing. 

The buffer corruption never happens when I am in the note grid editor pane in Ableton.  It is sounding samples in plugins perfectly while I edit note events.  It only ever happens precisely when I reach for the main transport control in the arrangement window above and press Play.  This seems to cause it to corrupt.  It does not always do it, in fact, I have had only one incident today so far, while editing, but when it goes, it is always when I click Play. 

What I experience in audio is an attempt at the sound, but it's like it's been bit crushed down to 8bit, or silence - it's mostly the corrupted audio.  The error counter does not seem to increment at all when this happens.  I am keeping a log.

In fact, the error counter can increase on its own, when I the DAW is idle.

5

Re: Ableton UFX buffer corruption when editing MIDI

This is a normal UFX with USB2? Are you aware that USB3 includes USB2 as totally separated system? All devices on that hub/connection that use USB2 share the same USB2 hub. Despite USB3 you have no additional resources. Connect the UFX to a free USB port on your computer, and read the manual's notes about finding the best USB port.

As long as you see USB errors you don't need to wonder about the issues with Ableton.

Regards
Matthias Carstens
RME

6 (edited by TR62 2019-07-16 18:00:49)

Re: Ableton UFX buffer corruption when editing MIDI

Thank you, Matthias. 

No, I was not aware of that USB3 and 2 were different subsystems.  I had assumed fallback from 3 to 2 over the same cable was simply a speed difference.

Interestingly it has been better behaved since removing the Launchpad.

Using ports directly is challenging, and not really desirable here.  The PC is rackmounted and roadcased, so all USB ports are buried in the roadcase and rear-facing - so all important ports are mounted in patchbays and repeated to the front.  There is  a 1m cable unavoidably from the back of the PC to that patchbay.  We used a hub in the front (in place of a dumb D-type feedthrough).  The UFX (yes, a normal v1), is in a separate road case, with a whole bunch of 19inch FX and A/D units - lots of wires, and again patchbays to the front.  Not likely to be bring the two any closer to be honest.  If we remove the hub altogether, the fallback will be a feedthrough, although we still face around 2.5m of USB cable between the two devices and have to rely on motherboard power.  Any direct connection without the patchbay/hub would be a royal pain to connect/disconnect with each show.  There is really only access to mains at the back of the roadcases.  A USB connection using just a single cable would also have implications where crew may not notice it, and destroy either PC or UFX by moving the two cases about without first disconnecting that tiny cable.  I much prefer patchbays for their reslience to such "accidents".  I guess we could try 2x 1200mm cables joined end to end, and leave one half in each road case, with strain relief to prevent damages.

The best results yet are with PC > 1m > Hub > 2m > UFX, with only the MIDI router and UFX connected to the hub.  However, although it can be stable for 30mins with no errors at all, it still loses connection when editing sometimes, with changes in focus as described.

I'll press on and try some other configurations.

Thanks for your input - appreciated.

7

Re: Ableton UFX buffer corruption when editing MIDI

Also take a look on active USB2 extensions. Not expensive and gives you 5, 10 or more meters without USB error. Provided their source/port works correct, of course.

Regards
Matthias Carstens
RME

8 (edited by TR62 2019-07-18 13:14:15)

Re: Ableton UFX buffer corruption when editing MIDI

That's a great suggestion Matthias, thanks.

I have now configured the UFX with a temporary trailing lead from the back of the 12U rack, and connected directly to a motherboard USB3.0 port, placing all the dongles on the hub, and moving it down the system device list.

With this change , yesterday I had "Errors : 0/0" for 12 straight hours of use, so the system is working when configured as you suggested.  Thanks for your insight on this - saved me a lot of time.

So the suggestion to use a powered extender is timely, as all we have to do now is figure out how to ruggedise it.  I will try a couple of D feedthroughs and some very short USB cables rack-to-rack - for now that we have a working solution, we can fall back to that if needed.  I'll postback with results.

Thanks again for your help.