• Registered: 2007-08-29
  • Posts: 65

Topic: Fireface 400 Phantom Power Bug?

Background:
I only turn on phantom power when I need it.
When I'm finished recording, I always turn it off.
I shutdown my computer when I'm done for the night.

Twice this has occurred:
Record some vocals using Input 1 with phantom power enabled.
When I'm finished recording, I turn off the phantom power.
I shutdown my computer when I'm done for the night.

The next time I turn on my computer, I'm warmly greeted with howling feedback!
When I open the Fireface Settings, the 48V box is NOT checked for Mic 1 or 2.
Since my mic is plugged into Input 1, I quickly enable and then disable the phantom power for Mic 1 and the feedback is gone.

The first time it happened was a few months ago.
It blew one of the HF drivers in my monitors.
It just happened now.

Anyone else ever have phantom power be on, even though in Fireface Settings it's NOT enabled?

Driver version: 3.02
Firmware: 1.70

Macmini '19 3.2 GHz 6-Core i7, 32GB RAM, MacOS 10.15.2, LogicProX 10.4.8, FF400, UAD2 Satellite Octo
  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,782

Re: Fireface 400 Phantom Power Bug?

The state with 48V on may be flashed into the unit... What does the LED do when you switch the FF on without the computer?
Just flash the current state without, and you should be ok again. If not, please report back.


Regards
Daniel Fuchs
ME

Regards
Daniel Fuchs
RME

RME Support's Website

  • Registered: 2007-08-29
  • Posts: 65

Re: Fireface 400 Phantom Power Bug?

The 48V LED does not come on when I switch the FF on without the computer.
Plus, since it has only happened twice...months apart...it's not flashed into the unit, or it would happen every time.(Right?)

I just flashed the current state without phantom power enabled.
I'll report back if it happens again.

Macmini '19 3.2 GHz 6-Core i7, 32GB RAM, MacOS 10.15.2, LogicProX 10.4.8, FF400, UAD2 Satellite Octo

4 Reply by Laurence Payne (edited by Laurence Payne 2012-02-11 16:05:02)

  • Registered: 2007-05-09
  • Posts: 174

Re: Fireface 400 Phantom Power Bug?

Switching the phantom power is a very original way of turning a mic off  :-)

Whatever's happening, it's a timely reminder to all of us that the FIRST thing you do when shutting down a system is to turn down the power amps.  And when starting up turn them up last, and cautiously!  Otherwise, make sure you have a stock of replacement tweeters.

5 Reply by redlogic (edited by redlogic 2012-02-13 07:49:29)

  • Registered: 2007-08-29
  • Posts: 65

Re: Fireface 400 Phantom Power Bug?

It just happened again yesterday on startup.

48V not lit on the front panel of the Fireface
48V not checked in the Fireface Settings

Yet...the condensor mic (Mic 1) has phantom power on startup.

Checking and then unchecking the 48V box for Mic 1 in Fireface Settings disables phantom power.

Anyone else ever seen this?

Macmini '19 3.2 GHz 6-Core i7, 32GB RAM, MacOS 10.15.2, LogicProX 10.4.8, FF400, UAD2 Satellite Octo
  • Registered: 2007-08-29
  • Posts: 65

Re: Fireface 400 Phantom Power Bug?

Daniel,

In researching this issue, someone brought this 2006/2007 Gearslutz thread to my attention:
RME FIREFACE 400 USERS MUST READ THIS!

Apparently, this was a firmware problem that was addressed with a firmware update.
The problem occurred in standalone and non-standalone mode.
In addition, the problem only occurred in non-standalone mode under very specific conditions.

It is limited to a very rare combination of several factors (in firmwares < 1.48):
For this to occur, all of the following settings had to apply (i.e. be stored in the FF400's flash memory):

Both Mic Gain settings at 0 dB and
Both Pad switches off and
Both Instrument switches off and
Both Phantom Power switches off and
No previous change to these settings since the FF was switched on. Manually recreating this combination of settings will not cause incorrect phantom power display.

As stated previously, my firmware version is 1.70.
This is well beyond "< 1.48", yet I am definitely experiencing this issue or one that is very similar in non-standalone mode.

Also, my Fireface settings differ from the ones mentioned as being critical to reproduce this anomaly.

As instructed, I flashed the current state without phantom power enabled on 2-9-12.
The problem occurred again on 2-13-12. The Fireface settings had not been changed.
The problem is intermittent.
It didn't occur between 2-10 and 2-12, and it hasn't occurred since 2-13.
The first time it occurred was in may 2011.

But, it does occur.

Is it possible that a firmware (or driver) update subsequent to firmware version 1.47 could have somehow reactivated this bug, even with Fireface settings different from the ones mentioned as being critical to reproduce?

I trust you will forward this info to those who can help solve this problem.
Something is not right.

Thank you.

A screenshot of my Fireface Settings is below
http://img594.imageshack.us/img594/6669/firefacesettings.png

Macmini '19 3.2 GHz 6-Core i7, 32GB RAM, MacOS 10.15.2, LogicProX 10.4.8, FF400, UAD2 Satellite Octo