This may seem like an odd request. Are there are test tracks I can get a hold of which can verify a bit-perfect playback path for plain old CD-quality 16-bit 44.1kHz PCM?
The playback path in question is iTunes 12, AirPlay to Airport Express, optical to DAC. AirPlay has been tested and verified as bit-perfect by different people in the past, but there’s some people suggesting that’s no longer the case.
Not at this time. The test pattern was designed for testing both 16 bits and 24 bits, but the recognizer for the legitimate 16 bit pattern with 0s on the bottom (which is how the FPGA sees things) isn’t in the FPGA.
A hack test is to play a DTS encoded track and see if a DTS decoder gives good output or crap.
OK, thanks for the info. The DTS suggestion is a good one, though I don’t own an AVR or have any DTS-encoded tracks, so I’ll just let the bit-perfectness of AirPlay be somebody else’s problem 