sbn;131667 Wrote: > Okay, so the attenuation might be a feature of the DAC, adjusting some > kind of master voltage in the DAC, affecting the output?
Yes, it's internal to the DAC chip itself. There are at least two ways it could be done. One way might be to scale the digital data prior to conversion to analog inside the chip. Another possible way is in the analog domain. Digitally-controlled analog volume controls, such as the Burr-Brown/TI PGA2310 chip, have a switched resistor network used as the feedback network of an op-amp. By switching different resistor networks in and out, using FETs as switches, the analog gain of the op-amp after D/A conversion could be varied. The choice between these techniques is probably done on the basis of cost. The DAC chip is almost the last thing before the analog output as far as signal processing is concerned. There may be some additional analog filters after the DAC, but that's about it. The digital signal from which S/PDIF is obtained is picked off before it ever gets to the DAC. -- andy_c ------------------------------------------------------------------------ andy_c's Profile: http://forums.slimdevices.com/member.php?userid=3128 View this thread: http://forums.slimdevices.com/showthread.php?t=26788 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
