JJZolx Wrote: > It's interesting that a guy who would charge $500 to mod your $300 > Squeezebox2 would advocate using the internal digital volume control. I don't read it as actually *advocating* it. What he actually says is: "for those of you who want to use the built-in 40-step volume control (performed digitally before the internal DAC), this reduction in voltage allows for a more usable range in the volume control". To me, that isn't saying that you should use it, but that if you do then you'll be able to use a greater range of adjustments due to the lowered output voltage.
But your comment brings up an interesting question: what's wrong with using the digital volume control? Many audiophiles here seem to just take it as read that you shouldn't, but it's by no means clear-cut. The digital data (both internally and as delivered out the SPDIF port) is 24 bit. With the volume control at VC=40, you get a theoretical 144dB of dynamic range. How loud do you want to listen? Let's say you want to listen at a maximum of 120dB. Setting things up so that VC=40 gives 120dB, the theoretical noise floor is 24dB below 0dB (ie. definitely, without a shadow of doubt, inaudible). Now say you want to turn it down a bit, let's say down to 96dB (ie. 24dB down). To achieve this, you'll need to sacrifice 4 bits of resolution, which brings the dynamic range down to 120dB. And where is the noise floor now? It's *still* 24dB below 0dB. And this holds for *all* volume settings - the theoretical noise floor remains at the same inaudible level, regardless of the setting. This is the beauty of digital level control: distortion and noise increase as the level goes down. This is exactly what you want: at lower volumes, distortion+noise can be allowed to increase, because it remains below the threshold of audibility. Contrast this to a traditional analogue potentiometer, where the tracking gets decidedly vague at very low settings, resulting in undesirable image shifts as you turn things down very low. *If* you have 24 bit signals to play with, then level adjustment is best done digitally (provided it's done properly, of course, which I'm sure is the case with the SB2). Those of you with high-end 24 bit DACs fed from a fixed SB2 digital output and subsequently feeding an analogue preamp should experiment with connecting the DAC directly to the power amps and using the SB2's digital volume control. The results may surprise you. (Hint: my preamp is currently for sale on eBay as a result). -- cliveb _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
