[linux-audio-user] Re: RME hammerfall DSP Multiface: help needed

[Mark Knecht]

>
> I can report a small success :-)
>
> Robert Epprecht <epprecht at solnet.ch> writes:
>
> > I am currently reading the manual of RME and...
> was trying out this and that, (but had *not* used any amixer commands
> in this session)  I noticed suddenly that some of the analog inputs
> had started to display some very low signal *numbers*. I had only
> seen them displaying -infinity before.

-infinity means 'all zeros'. When you plug in an external device you begin
to see its 'noise floor'. For instance, on my ADAT inputs, if I hook one to
an AI-3 which has a spec'ed noise floor of -98db I see the inputs register
about -99db to -101db, much as you would expect. However, if I hook an ADAT
input to my Pro Tools rig and its ADAT outputs I still register -infinity
since Pro Tools sends 'all zeros' on ADAT outputs that are not being used.
Makes sense..

>
> When I plugged in a sound source the input meter *did* show the signal.
> I have no idea, why the signal is shown now, and never was before.
> (I had tried a few times before).  Very confusing.
>
> I was not able to get an output signal, whether on the output jacks
> nor displayed by the meters.  Of course I have tried to set routing,
> faders and un-muting, but had no success.

This is disappointing. Did you do the lspci -v and get the info on your
firmware revision?

>
> While the higher number (analog) inputs still showed -infinity they
> changed to display the noise floor as soon I had plugged a cable to
> the inputs, and continued to do so, even when I unplugged the cable.
> Under 'another' OS I have seen them behave like this, so I think
> this is normal (I don't remember having seen -infinity there, only
> the noise floor, but this could be an accident).

In your case the MultiFace has internal A/D converters, correct? In this
case I do not know why it should change either.

As an experiment you might try a clean boot, open hdspmixer and hdspconf,
and then change some clock settings in hdspconf. Maybe that will wake it up
and get it to display things correctly?

Or possibly even though the MultiFace has A/D's they are not hooked up
initially and stay that way until you plug something in? Just a thought.

>
> I'll try to find out under what conditions the signal starts to show
> up and will report what I find...
>
> Robert
>
>