• Registered: 2007-08-06
  • Posts: 10

Topic: FireFace 800 Mic inputs blown

Hi All,

Not been posting here for awhile but am hoping someone out there can assist if possible?

My FF800 has developed a fault on mic inputs 7 & 8 (presumably because they're on the same part of the board). The fault is whenever phantom power is switched on for either of these channels there is audible background noise and static, anywhere from 3 to 9 db. This noise is not present when using as a straight forward mic input.

I read somewhere here that it could be the transistors causing the noise but as i'm not electrically minded i wouldn't know where to start. I doubt there is an easy fix other then a stand alone dual phantom power supply, but is there a UK based service centre that anyone can recommend which has a quick turnaround time? I'm due to record a choir in 2 weeks so having it back up and running would be a blessing.

Thanks in advance,

SkM

2 Reply by S-E Hansson (edited by S-E Hansson 2012-11-12 14:08:37)

  • From: Gothenburg, Sweden
  • Registered: 2007-05-01
  • Posts: 441

Re: FireFace 800 Mic inputs blown

Hi,

Do you see static all the time with levels at lowest and normal mic input
and phantom power !?

even check with different microphones, cables and other audio device/mixer board
to be sure and rule things out one by one.

regards S-EH

  • Registered: 2007-08-06
  • Posts: 10

Re: FireFace 800 Mic inputs blown

Hi S-EH,

Thanks for you reply.

I've tried all sorts of combinations of different cables, mics etc. but it only happens on channels 7 & 8 where as the same combinations work perfectly fine on channels 9 & 10. The background noise doesn't occur when phantom power is switched on for ch 7 & 8, but only when an XLR is connected which seems a bit strange. Is that because the PP is then being used possibly?

Apologies, i know next to nothing about electronics ;-(

Thanks
SkM

  • From: UK
  • Registered: 2012-11-21
  • Posts: 2

Re: FireFace 800 Mic inputs blown

I too have just reported noise on mic inputs 7 & 8. Input 7 is much worse and the noise is present with or without mic/cables attached. I've sent some noise samples to support@ as I think that's the right thing to do.
The unit was bought in 2009 and I'm shocked that the preamps should go bad so soon into the unit's life, as it's very good in all other respects.
Does anyone in the UK do 'advance replacements' as the studio can't be without an interface. Or perhaps this is an RME recall issue?
Cheers,
Al @ Dreambase Studios

dreambasestudios's Website

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,783

Re: FireFace 800 Mic inputs blown

Does the problem occur with and without phantom power?
There is certainly no "recall issue", this is not a common problem. As for a replacement, Synthax UK cooperate with a loan company that will offer reduced rates to their customers.

Please fill this form to start proceedings: http://www.synthax.co.uk/RMA

Regards
Daniel Fuchs
RME

Regards
Daniel Fuchs
RME

RME Support's Website

  • From: UK
  • Registered: 2012-11-21
  • Posts: 2

Re: FireFace 800 Mic inputs blown

Hi Daniel,
Thanks for your reply.
Yes it's marginally noisier with phantom power switched in, which it is all the time in our studio.
A pro audio company I used to work for did 'advance replacements' as part of the repair deal so I hope it's not too expensive with the repairs and loan.

I'll probably do this in the new year and manage for now with a couple of dedicated preamps as it's a bit busy but thanks for the link and reply.

Al @ Dreambase Studios

dreambasestudios's Website

7 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,604

Re: FireFace 800 Mic inputs blown

> phantom power switched in, which it is all the time in our studio

And most probably explains the damage. Every time you unplug and plug a mic 48V should be switched off first. Or sooner or later the protection diodes will die themselve.

Regards
Matthias Carstens
RME

MC's Website

  • LH800
  • ADAT user
  • Offline
  • Registered: 2012-09-18
  • Posts: 18

Re: FireFace 800 Mic inputs blown

I’m writing because I’m trying since october to solve a problem with the signals I get from using the inputs 7 and 8 of my FF800 and I think the problem you may have relating to expose mine. I've been observing, at displaying oscillogram, that speech signals recorded by a pair of microphones with XLR connectors connected to RME console show bias offset. Nor am I an expert on electronic issues and I would like to ask the following:
To JKmachette: how do you active inputs 9 and 10 in the dialog that only offers 1, 7 and 8 options?
To use analog rear inputs do you use a XLR- balanced 1/4 inch adaptor?
To dreambasestudio: How do you use the microphone preamp? Do you use it instead the console? Thank you very much for your help.
Lorena.-

  • Registered: 2007-08-06
  • Posts: 10

Re: FireFace 800 Mic inputs blown

Hi,

"how do you active inputs 9 and 10 in the dialog that only offers 1, 7 and 8 options?"

In the FireFace Settings you can switch on Phantom Power for channels 7 to 10 in the 'phantom power' sub box just under the 'Level in' & 'Level Out' selection box (top right hand side).
Because of the problem i'm having with input XLR ch 7 & 8, i'm using a standalone dual phantom power supply which works so if anyone else is having a similar issue, it's worth a try till the unit can go in for repair.

"To use analog rear inputs do you use a XLR- balanced 1/4 inch adaptor?'

I've never used an XLR adaptor for the rear inputs, always 1/4 inch jacks.

Hope the above helps ;-)

Thanks,

SkM

  • LH800
  • ADAT user
  • Offline
  • Registered: 2012-09-18
  • Posts: 18

Re: FireFace 800 Mic inputs blown

Thank you very much.
You helped me a lot!!! Just one question, probably silly, how do you connect phantom power supply to the console in order to digitalizing?
Thanks again.
Lorena Ham.-