Hi, I took the one that I have apart, if anyone is interested.
The main chip is the TI PCM2902E It also has 4 op amps, they are all TI 2353UA's I admit that I'm a little surprised that this interface doesn't have S/PDIF connections. The PCM2902E can handle S/PDIF (as opposed to the PCM2900 which is the same chip without the S/PDIF option). It also has a AMS1117 voltage regulator. Overall there's not much to these units. Lorne Tyndale > > Do we know if those output lines are *true* balanced/differential, and not > just that resistor trick (Impedance balanced send, > http://www.soundonsound.com/sos/oct13/articles/qanda-1013-4.htm)? > I'd believe that USB power may not be enough to deliver a nice stout +4, so > while ten dB down on a balanced output doesn't smell right, it makes some > sense. > > Has anyone had success with Henry Engineering's "USB Matchbox II"? At $550 > MSRP it's a bit steep, but Hank's been getting it right for decades now. > > *Alan Peterson *KJ4IVD > Arlington VA USA > > > > On Wed, Sep 23, 2015 at 7:18 AM, Rob Landry <[email protected]> wrote: > > > > > > > On Tue, 15 Sep 2015, Rob Landry wrote: > > > > On Tue, 15 Sep 2015, Lorne Tyndale wrote: > >> > > > > For a USB interface that does balanced audio, I've had good luck with > >>> the following: > >>> > >> > > http://www.mcmelectronics.com/product/555-17815 > >>> > >> > > I'm testing one right now on an Intel NUC running Rivendell. The output > >> levels seem awfully low; I'm not sure why. > >> > > > > A 1 Khz tone played on rdairplay at the level indicated as nominal comes > > out of this adapter at -10 dBu, measured with a VOM with no other load. > > That's with the volume turned up all the way in alsamixer. > > > > This adapter is not capable of +4 dBu output. Its output does appear to be > > balanced, though. > > > > I did not test the input to see how it handles a tone at +4 dBu. > > > > > > Rob > > _______________________________________________ > > Rivendell-dev mailing list > > [email protected] > > http://caspian.paravelsystems.com/mailman/listinfo/rivendell-dev > > _______________________________________________ Rivendell-dev mailing list [email protected] http://caspian.paravelsystems.com/mailman/listinfo/rivendell-dev
