• Registered: 2015-03-15
  • Posts: 25

Topic: Preamp mode behavior

I had my ADI2-Pro in “auto mode” hooked up to a computer via USB.  The ADI-2 Pro analogue outputs were routed to an external mixer whose master outputs were routed back into the ADI 2 pro analogue inputs for mixing/summing duties.  This was fine when “USB mode” was activated.  When I left the computer unattended for a while it went to sleep and “pre-amp mode” auto-activated.  This created a feedback loop in the RME that seemed to self-correct after a second or so (overload protection kicking in?).  Fortunately I had muted my monitor sends.   Lesson learned - only manual mode selection for me. 

Is this normal behavior for the unit?  Any chance damage was done?  What is the mechanism by which the adi-2 pro self-corrects and stops the feedback?

2 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,837

Re: Preamp mode behavior

Feedback requires gain within the loop, so you amplified the ADIs output signal with the mixer or had set a lower ref level for input than for output, etc. 'Feedback' is a normal audio signal for the device, there is no way to cause damage. Only speakers might get a problem at higher levels.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2015-03-15
  • Posts: 25

Re: Preamp mode behavior

Thank very much for the reply.  There was indeed some gain on the channel.