On Wed, Jan 08, 2014 at 05:04:38PM +0100, Robin Gareus wrote: > On 01/08/2014 04:43 PM, Fons Adriaensen wrote: > > On Wed, Jan 08, 2014 at 03:51:41PM +0100, Robin Gareus wrote: > > > >> I had calibrated -18dBFS on all of them to the same source (a 1KHz sine, > >> which I believe to be 0 dBu). That's how I found out about the rubber > >> controls effect in the first place. > > > > O dBu ? So you measured the line inputs, not the mics ? > > I don't think I did. I used an unbalanced jack (out from a 4th > soundcard) -> balanced XLR (pin 2,3) to calibrate. > > Then a XLR plug with a resistor between pin 2,3 for the noise measurement. I just checked the calibration data for mu UA-5, which as far as the analog part is concerned, is similar to the UA-25 (apart from having separate line inputs which do not pass via the mic preamps). At max gain, the required input level for 0 dB digital is around -42 dBu, fairly normal for a mic input. To produce -18 dB digital with 0 dBu input you'd need 60 dB less gain. Maybe that's possible with the gain pots just above the minimum, but anything measured with that setting wouldn't be very representative. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
