jaffa_777 wrote: > I was wondering if the squeezebox has true digital outs. How does it > control gain/volume to the digital signal. I thought a digital signal > out was just pure information of 1's and 0's? But it seems to work as a > preamp as well on the digital side?
At the loweest level, it is indeed just 1's and 0's. But then, so is every piece of information stored on your hard drive. The Squeezebox digital out sends data using SPDIF [1]. For the purposes of explaining digital volume to you, this essentially means it it sends numbers representing the signal level sampled at intervals of 1/sample frequency. Using 8 bits as an example (the Squeezebox actually uses 24) you might have a stream of "numbers" like this: 11010110 11001111 11010101 ... In order to reduce the "digital" volume, all that is required is that the numbers that are sent are all reduced by a fixed ratio, e.g.: 00001101 00001100 00001101 ... As you can see, you lose information as the digits disappear. However, remember I said the Squeezebox uses 24-bits? Well, CD audio is only 16-bit so the 8 low bits are generally zero. e.g.: 111111111101011000000000 111111111100111100000000 111111111101010100000000 ... Now, if we reduce the volume: 000011111111110101100000 000011111111110011110000 000011111111110101010000 ... Voila - no loss of resolution! I hope this all makes sense. R. [1] http://en.wikipedia.org/wiki/Spdif _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
