Topic: Fireface UC - Digital Noise/Hiss Issue

Hello all,

First time poster and I am hoping that somebody can help!

I own a fireface UC and I have been having issues regarding noise/static/hiss in the past month or so. For info, I have owned the Fireface UC since 2014 and I use Logic Pro X. The unit has been well looked after and has not had any bumps or bangs. I have not changed the USB cable since purchasing the UC.

The noise/hiss is in the higher registers (10000 Hz +) and this happens when I use my both my outboard pre amps (Focusrite ISA 2 & UA 6176 into the UC’s balanced line inputs) or the Fireface UC’s own inbuilt pre amps.

When looking at metering, the noise floor is sitting mostly around -90db RMS, with the pre amps enabled, but this is without instrument connectivity. This will rise to around -80/-70db and sometimes more when I plug in a guitar (DI’d) or mic etc…

My buffer size is at 128 when recording and my sample rate is at 44.1.

Any help would be much appreciated.

Joe

Re: Fireface UC - Digital Noise/Hiss Issue

Are you sure it's not the source? Have you tried other sources? Can you upload a sample somewhere?

Regards
Daniel Fuchs
RME

Re: Fireface UC - Digital Noise/Hiss Issue

RME Support wrote:

Are you sure it's not the source? Have you tried other sources? Can you upload a sample somewhere?

Thank you for your reply.

By source, do you mean the outboard pre amps? The noise/hiss occurs when using these, but when I disconnect these from my UC and use the inbuilt pre-amps, the noise/hiss is there too.

I’ve tried tracking with electric guitars, acoustic guitars and analog synths and the noise/hiss is still apparent. I’ve also purchased new cables and removed any objects that could cause interference in my space.

I will send through an audio clip ASAP.

Thanks again.

Re: Fireface UC - Digital Noise/Hiss Issue

Hi @joedavidrobinson1985,

I just had a smiliar issue, and after days (and nights) of investigation, turned out it was my devolo Powerline adapter plugged into the socket next to my music rack power supply that was causing the hiss in the instrument inputs of my Fireface and my SPL Channel 1.

Plugging the rack into the built-in socket of the devolo (that has got a built-in filter) solved the issue immediately.

Regards
Thomas

Music lover with lots of gear, little talent, but loads of enthusiasm!

Re: Fireface UC - Digital Noise/Hiss Issue

hunsitho wrote:

Hi @joedavidrobinson1985,

I just had a smiliar issue, and after days (and nights) of investigation, turned out it was my devolo Powerline adapter plugged into the socket next to my music rack power supply that was causing the hiss in the instrument inputs of my Fireface and my SPL Channel 1.

Plugging the rack into the built-in socket of the devolo (that has got a built-in filter) solved the issue immediately.

Regards
Thomas

Hi Thomas,

Thanks for the reply!

Shortly after posting this thread, the hiss/noise magically disappeared, so I didn’t take this any further. I had also spent countless days and nights trying to rectify the issue, but nothing worked. Then one day, the hiss was no longer there. I don’t know whether it was something I did, or just devine intervention.

Unfortunately, a few days ago, the hiss/noise has returned! So it looks like I will be spending the next few days/evenings trying to sort this out.

At the moment, my USB is going from the fire face and straight into the USB port on my Mac. I’m guessing that it might be worth  investing in an adapter of some sort, such as the devolo.

Thanks again,

Joe

6

Re: Fireface UC - Digital Noise/Hiss Issue

The Devolo transmits ethernet via power lines. You don't want to buy that if you don't need that feature.

If the hiss is caused by the USB connection - there are not expensive USB isolators available.

Regards
Matthias Carstens
RME