Why do I get this weird noise when I try to record audio?

[MitchT]

When I try to record audio to my MacBook Pro I get a weird oscillating noise on the recording. The audio masks it but it's audible during the silence before and after the audio starts/finishes and during quieter parts. It makes no difference whether I record into Quicktime or Logic Pro. In either case, I'm using an Edirol UA-1X audio-to-USB interface to get the audio signal into my Mac. I've had it when recording the outputs from either my mixing console or my DAT machine to my Mac, so I suspect it's the interface that's the issue. Does anyone know why it's happening and how to get rid of it?

I've boosted the noise with some Gain and EQ in Logic Pro, purely because it's so quiet. Otherwise, this is exactly what it sounds like...

https://soundcloud.com/mitch-tmsn/audio-recording-...

[niallf]

Does it do it when the power supply is unplugged from the Mac i.e. running on battery?

[br d]

Was going to suggest the same. If you're happy with the fidelity of your cables and connectors I'd be looking for something nearby causing interference.

[FurtiveFreddy]

You could also try a ground loop isolator on the input to the Edirol. They're cheap and can eliminate noise when all else fails.

[MitchT]

FurtiveFreddy said:

You could also try a ground loop isolator on the input to the Edirol. They're cheap and can eliminate noise when all else fails.

Tried one. it reduces the noise but doesn't eliminate it.

niallf said:

Does it do it when the power supply is unplugged from the Mac i.e. running on battery?

Yes, tried that.

Answer
Some time spent extensively researching this online suggests that it's a design fault in the interface. That all do it apparently. Looks like I'll be shopping for a new one!

[suthol]

Some computers are internally noisy as the electrons charge around doing their thing, fans if they have them don't help either

[MitchT]

suthol said:

Some computers are internally noisy as the electrons charge around doing their thing, fans if they have them don't help either

I bought the interface many years ago, used it originally with an old G5 Power Mac running Logic Pro 7, then a 2008 MacBook Pro running Logoic Pro 8 and, most recently, with a 2017 MacBook Pro running Logic Pro X. It does it on all of them. I've never needed it for anything serious, hence why I've never tried hard to sort the issue previously.

[suthol]

MitchT said:

I bought the interface many years ago, used it originally with an old G5 Power Mac running Logic Pro 7, then a 2008 MacBook Pro running Logoic Pro 8 and, most recently, with a 2017 MacBook Pro running Logic Pro X. It does it on all of them. I've never needed it for anything serious, hence why I've never tried hard to sort the issue previously.

Fair enough, just thought I'd put it out there.

The interface isn't shot by any chance, I had a Behringer go noisy, now using Focusrite which is far superior

[MitchT]

suthol said:

The interface isn't shot by any chance, I had a Behringer go noisy, now using Focusrite which is far superior

If it is then it was shot from the first time I used it. I think it's just a design flaw as a hunt around online revealed the same issue for everyone else who has one and the consensus that they all do it.

[Escapegoat]

There is a design flaw in many setups that joins a digital ground with an analogue ground. It may not be the interface's fault, so much as it is the designers not understanding the many different ways we use this sort of gear.

The result in my case (Mac with Saffire interface and Korg Triton Taktile) was a very annoying variable buzz at higher frequencies than the usual 50/100Hz mains hum and buzz. This noise was transferred via the analogue input connections between the Korg synth and the interface. That noise varied in frequency and pulsing according to the digital processing being done on the Korg, so if I moved a slider or used the X-Y pad, the noise changed.

The solution was simple: a stereo analogue isolator between the Korg outputs and the interface' inputs. Lots of people have to use something similar in in-car systems where they are charging their phones from the car at the same time as connecting a 3.5mm stereo wire to the car stereo's Aux input.

This - https://www.studiospares.com/Studio-Gear/Signal-In... - is a spendy one aimed at studio users, but the size of the car market means that you can get super-compact cheapies for about £5 from Ebay.

(There are also isolating USB widgets, but they are more complex.)