Uprgrading my Metrum Octave DAC

Interesting Idea about coupling DAC directly to amp. 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?

Steve,

Which transformer would you recommend if implementing #4?

Lewis,

HNY to ya.

My source is a MBP running iTunes and Pure Music.

I use the free Apple Remote app to control the music selection and the SP17 remote for volume.

I can use any number of iDevices around here as a remote.

Burning my files as just wave files. Takes out the whole "which file type sounds better" issue since this is the original file.

I'm 99% 44/16 with maybe 10 higher rez albums. They sound generally a little smoother -maybe -but I find that it's really much more dependent on the original recording than the resolution.

Right now I'm just enjoying the music and about to embark on room treatments.

"An preamp is a preamp whether it's in the DAC or external. If you plan to control the volume, you are going to need one. The Octave does not even have a buffer and takes the output directly from the DAC chips. I choose to let a SP17 do the rest, partly because I love the ARC sound and partly because it's also a phono preamp and offers various input switching, remote volume, etc."

This statement use to be true, however there are new digital-only volume control technologies that allow the DAC line-out to feed the Amps directly, and I'm not talking about iTunes volume controlling 100% of the volume here. I'm taking about completely eliminating the preamp.

"Not interested in transformers, or capacitors anywhere they can be eliminated, especially directly in the signal path."

I understand your reticence, however there are also new transformer technologies available that improve sound quality dramatically. I use simple a buffer transformer after my DAC. Makes a world of difference. Here is why:

http://www.audiocircle.com/index.php?topic=108715.0

Steve N.
Empirical Audio

"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