On Sat, Feb 18, 2012 at 01:47:03PM +0100, Jörn Nettingsmeier wrote: > fons, after i read your remark i asked around, and yes, the ff800 does > indeed use servo-driven outputs, so the voltage difference is > intentional and no cause for concern. i'll definitely investigate the > level differences between channels, but as you said, i'd better do that > with a sound card rather than a meter.
You could use a multimeter to _compare_ levels even if the actual value is wrong. The important point with those servo-driven outputs is that you should always measure between hot and cold, it's the only voltage that is really defined by the line driver. The signal on each of them separately w.r.t. to ground depends on how the other one is loaded. It's done by a feedback circuit that tries to make the sum of the two output currents zero. If you have a good quality balanced line input with repeatable or fixed gain (e.g. a multiface) just calibrate it once against a good meter and then use jnoisemeter to measure RMS. The app also has some standard filters and detectors for noise measurements. Ciao, -- FA Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl. _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
