"Which DACs do you know of that are capable of doing this? I guess you just need a DAC with the right output impedance, why do you need balanced cables though?"
Any DAC with low output impedance can be used, lower than 50 ohms is good. If you drive the music from a computer, then the software player can control the volume. The problem with using most DACs line-out and controlling volume using software is the danger of having max volume and blowing up speakers. As for audio quality, as long as you use a max of -10dB and no more, the sound quality will not be impacted. This means using DACs with variable gain. The danger of speaker damage is still there. Therefore, I dont recommend this technique.
One DAC that you can drive line-out and actually control volume on is the Overdrive SE. This uses a digital volume technology that does not change the data. It changes the reference voltage of the D/A. The advantage of this is that it adds no actual parts to the signal path and changes nothing in the gain stage when the volume is adjusted. The THD actually decreases as the volume is lowered, unlike any other volume technology. This volume controls all digital inputs, so it can be used with computer or Transport.
Steve N.
Empirical Audio
Any DAC with low output impedance can be used, lower than 50 ohms is good. If you drive the music from a computer, then the software player can control the volume. The problem with using most DACs line-out and controlling volume using software is the danger of having max volume and blowing up speakers. As for audio quality, as long as you use a max of -10dB and no more, the sound quality will not be impacted. This means using DACs with variable gain. The danger of speaker damage is still there. Therefore, I dont recommend this technique.
One DAC that you can drive line-out and actually control volume on is the Overdrive SE. This uses a digital volume technology that does not change the data. It changes the reference voltage of the D/A. The advantage of this is that it adds no actual parts to the signal path and changes nothing in the gain stage when the volume is adjusted. The THD actually decreases as the volume is lowered, unlike any other volume technology. This volume controls all digital inputs, so it can be used with computer or Transport.
Steve N.
Empirical Audio