Audio noise when USB is connected

[romandesign]

I have loud audio noise on audio out when USB is connected to PC. Looks like a ground loop. Does anyone use ADUM3160 or ADUM4160 based USB ground isolator with Roland? Will USB interface work correctly when put through such device? It's not USB2.0 compatible, so it may not work, so I'd like to know if anyone tried before ordering one on ebay. Any other solutions? I have TASCAM 16x08 interface for SONAR, so I can't record FA audio through USB audio interface (I just use ot for MIDI and DAW control). Not sure what to do...

[Skijumptoes]

I get a bit of noise via the line outs when USB is connected for MIDI only, is that what you mean? It goes if i use old school MIDI.

I've tried balanced cables and that didn't eradicate the noise which really surprised me, which leads me to believe that the noise/interference is happening before the line out perhaps? However, i have noticed differences when moving the line out cables to sit in a certain position.

It's not a big issue for me as the interference is pretty low, but i'm really interested in seeing this thread develop if anyone finds a good solution, or adds to it.

romandesign - could you confirm if you're monitoring via the analog line outs, and not USB (Digital) Audio from the FA?

[romandesign]

Yes, that's correct. The noise is present in analog "line out" signal, when USB is used for MIDI. It's quite loud to be clearly audible when there is no music. It appears as soon as USB is connected to Roland. I sounds like a ground loop problem. The question is if an existing solution for USB ground isolation would work, as it's not USB2.0 compatible (speed is lower), or maybe there are other solutions?

I power PC and all music gear through UPS and power conditioner, so my power is clean. But there is lots of gear, so ground loop is possible, and hard to isolate.

I was able to connect analog line through a phantom-powered DI box with built in "ground lift" and it got rid of the ground noise (confirming that it IS a ground noise). However DI box introduces a bit of its own noise and I want a clean signal as direct as possible so I can record it in a clean manner.

[diego]

+1 happens to me too

[Skijumptoes]

Can you put a link here to the USB ground isolator you was looking at please? If it's a good price i may try one on amazon prime or something as they do simple returns if it doesn't work lol.

And yes, it does sound like it's USB ground loop related, at least my tests confirm that too.

Trouble is, this is quite common on Roland devices, i had a boutique that had the same issue, and also had it on another cheap Roland synth - think it was the SH-201. I mainly only really notice when i put the FA through an external FX unit or amp and i have gain/distortion dialled in. Or when i'm not playing anything and i can hear a noise coming through my speakers.

When you read up on the subject though, it's not an easy fix and it seems that the 'get out' clause is that USB Specs were never really designed with audio in mind.

[romandesign]

Here it is on Amazon that should work with Prime: http://a.co/3GNNAg1

I'm in Canada so can't buy it. I would appreciate if you let me know if you buy it, try it and share the results.

The chipset use in this and all similar devices only supports "full speed" and "low speed" USB, which is 1.5 Mb/s - it's confusing but "high speed" thich it does not support is faster than "fill speed". Basically is't not up to USB 2.0 spec, which prevents some drivers from recognizing device. Speed limit itself should not be a problem, even for stereo audio interface, and is much more than needed for MIDI. But it might not recognize the synth. Many people report great experience with using it with various audio interfaces and devices, but some do not work - depends on drivers I guess. Nobody, to my knowledge, reported experience with Roland full-size synth.

It's cheaper on ebay or Ali Express http://r.ebay.com/bq85Ff but will take 4 weeks to arrive, and can't be returned as shipping would be more expensive than the item.

[stevel]

We have two Little Phatty's at school that have the same problem.

Audio Out goes into a MOTU 828 interface.

USB goes directly into the computer.

If both the Audio and USB cable are plugged in, there's "ground loop" noise coming into the MOTU.

Our solution was simply to unplug the USB when recording audio directly from the LP, and to unplug the audio when using it as a USB Controller keyboard.

Not ideal in situations when you need to have both.

I don't even use USB with my FA. The MIDI goes to and from an interface, and the audio goes out to the interface as well.

[romandesign]

FA is built to control DAW (play/record etc.) which it can only do via USB (as it has 3 MIDI interfaces, not 1), plus my old-school MIDI ports are occupied by Mackie Control. I can't unplug USB as then I can't control DAW and can't play and record MIDI tracks. This is such a trivial task, FA is built to work with PC MIDI sequencers! I can't believe they haven't provisioned for this. They could have built in ground lift for USB or analog to get rid of this problem. SONAR also has a problem with this MIDI+audio sequencer with external synth mode: it delays midi to compensate for VST plugin latency so it plays back in sync, but then if I route external synth to an audio track to monitor and mix "in the box" - it delays the audio again, so it's out of sync when playing or mixing! I have to record that track first, only than it plays in sync. A simple button to disable MIDI delay compensation for specific track or MIDI device would have solved it, but no, that's too much to ask apparently... And then this noise... Arrgh...

[Skijumptoes]

Ok, so been testing with my setup and got my dreaded 'cable box of doom' from under my desk lol.

I didn't realise how bad my issue was, i use an analog mixer to route all my equipment to my Focusrite Saffire soundcard and to test the FA i disabled all other analog channels on my mixer so i could concentrate on the FA itself, and the interference got a whole lot louder!!

I then switched the sound card return channel back on my mixer, and the interference sound lessened to the levels i'm used to, i guess by having both channels enabled it was phasing each other out. Which is really quite interesting too and totally logical.

Was also a surprise to realise that even without monitoring via the sound card the interference was still making it's way there and back up the pipe to the mixer again.

Anyway, i've just sat here and gone through about 20 different USB cables and not one made a difference... Until the last one tried, it's black, it's thick, it has a small ferrite core/choke at the FA side of the cable. And wow! it has totally cleaned the interference up!

I have put my mixer on full gain and It's barely no difference than if i have it plugged into USB or not. I'm really quite stunned that this cable has worked so well!!

Trouble is, There's no part numbers for this cable, and i have no idea where i've got it from, but in my case it has eradicated the issue. I'm using balanced cables from FA to mixer, and mixer to Monitors.

I don't know if it's wired different or not, but if you have thicker cable AND ferrite chokes you can try, it may be worth a go?!

I'm not an expert in matters but reading online it seems as though USB ground issues only occur if the USB device is being powered via the same port, so if this has worked for me, does it mean we're just looking at general 'constant!' interference?

I'm now wondering if the sound coming out of my mixer has been compromised all these months via phasing issues too now lol, i'm so pleased you made this thread and i can't believe i've sorted mine out so easily.

[Skijumptoes]

SONAR also has a problem with this MIDI+audio sequencer with external synth mode: it delays midi to compensate for VST plugin latency so it plays back in sync, but then if I route external synth to an audio track to monitor and mix "in the box" - it delays the audio again, so it's out of sync when playing or mixing! I have to record that track first, only than it plays in sync. A simple button to disable MIDI delay compensation for specific track or MIDI device would have solved it, but no, that's too much to ask apparently... And then this noise... Arrgh...

There must be something in Sonar to adjust that, many DAW's you can disable the recorded delay compensation, but many depend on how you are monitoring when recording. Are you direct monitoring your FA, or are you monitoring via a record enabled track in Sonar? Many DAW's will use that distinction to handle the compensation.

Seriously consider using Reaper as a DAW, i've recently swapped over from Logic which is brilliant for MIDI but Reaper has so many great options, particularly for controlling the record delay if you're input monitoring on a per track basis.

[romandesign]

There must be something in Sonar to adjust that, many DAW's you can disable the recorded delay compensation

Funny thing is that there is a PDC button to disable delay, but it disables it everywhere, which breaks all the mix and VST processing etc. There is no button to control it over individual track. There is "MIDI timing" option to adjust MIDI delay but again, it works everywhere, and I'd have to guess the timing, and All VSTi are screwed then. There is no way to disable MIDI delay per track or per device, nor a way to disable PDC on per track basis.

I monitor via "record enabled track" (actually "monitor enabled"). I can monitor direct via soundcard mixer, but then I can't mix "in the box".

[Skijumptoes]

Did you see my post before that one regarding the USB cable fixing my noise issue?

[romandesign]

Did you see my post before that one regarding the USB cable fixing my noise issue?

No, what post was that?

BTW I was able to sort of solve the issue: first I rewired all electrical cords, unplugged everything leaving just UPS, PC, audio interface and Roland FA, all plugged directly to UPS - that did not help. I also tried different USB cable and replaced line out cables between FA and audio interface. Didn't help either. But I did verify that buzz was not present when plugging headphones to FA, but was present in audio interface headphone out. So it was FA line out that added it. What I ended doing is set input gain on audio interface at about 20% (knobs pointing at 9 o'clock), and setting volume knob on FA on maximum. Effectively I just increased noise-to-signal ratio by a lot. It gives me strong level in, the buzz is inaudible anymore, and SONAR shows -79db level on that input when silent. I think that is acceptable. Level at other inputs is about -83db to -86db, so -79 is fairly quiet. I added noise gate plugin just to completely close it when not in use. I would still like to use digital input instead, but ASIO doesn't work with 2 interfaces simultaneously, unfortunately. I can fake it with ASIO4ALL combining both interfaces, but then I get more latency than pure ASIO.

[romandesign]

Did you see my post before that one regarding the USB cable fixing my noise issue?

Ah, OK, I really missed your post :-)

Does it look something like this? http://r.ebay.com/cNN6CE
Does it have ferrite cores at both ends? How long is it?

Maybe I'll get one and see if it improves the noise levels.

[Skijumptoes]

Nope, i had several exactly cables like that and they didn't improve the interference at all, which is why i was amazed that this other black cable i had did work. The cable just felt thicker/stiffer when i picked it up.

It was more like this:-
https://www.amazon.com/Tripp-Lite-Hi-Sp ... B003MQ29B2

And reading the reviews on there, it looks like that is a true shielded cable with the ferrite chokes. I suspect you need both combinations for the cable to actually help.