NOS1 requires filtering for redbook music. Good filtering is CPU intensive. Think that you want a decent computer for that purpose.

Thanks for your detail answers again. I guess one thing that Audirvana lose out to XXHighend is the volume control as XXHighend volume control is lossless. Anyway, I like to have a tube preamplifier sitting between dac and power amp.

Thanks for the answers. Audirvana provides Apple CoreAudio and SRC libSampleRate filtering.

1. Which filtering do you use for Audirvana for your evaluation?
2. Do you use 4x or 2x upsampling or Maximum sample rate upsampling?
3. Do you use any filtering with Audirvana when playing >= 88KHz music?

I am very curious as I am a Mac user and wants to buy Phasure NOS1 DAC. It seems that Phasure NOS1 DAC works best with XXHighEnd player. I am just wondering why or how Audirvana changes all that.

BTW, I use Audirvana with other DAC. It is indeed the best Mac music player out there.

I have a few questions:

1. Are you running 44.1 with Audirvana? As far as I know, Audirvana does not do any filtering if we do not choose upsampling.

2. What is so special about Audirvana compared to your Arc Prediction?

3. Are you running OSX 10.6 or 10.7?

4. Does Phasure NOS1 support integer mode?

Thanks!