Airpot Express - Upgrade amp or DAC?

"Steve, I'm aware of changes you made to DAC1. These changes, as I remember eliminated jitter reduction ability of DAC1."

Only on the I2S interface, not on the S/PDIF input. I am a firm believer in not doing resampling in the DAC, so this interface provides that. Driven with a low-jitter source, this I2S is stellar.

"Effects of jitter are not even detectable buried deep in -130dB noise floor according to many different reviews."

Then why can I easily hear these differences? Why do other reviewers hear them?

For around $1K you could have a Metrum Octave.

Steve N.
Empirical Audio

Steve, Isn't Metrum Octave a NOS DAC? I would need reclocker for best results with AE. Many people go for NOS claiming ill effects of digital filtering (pulse response) but reclocker most likely involves digital filtering defeating purpose of NOS. Did you hear anything about Benchmark DAC2 HGC?

"Then why can I easily hear these differences? Why do other reviewers hear them?"

I don't know. It could be many reasons starting from not bit perfect sources, playback programs that do processing of the data, ground loops etc. or it is possible that my hearing is not that good or I am under placebo effect after seeing FFT plots. I've read reviews claiming audible difference but also read many reviews being unable to detect the difference. One thing for sure - almost everybody praised the clarity, some even calling it "ultra clean" what wouldn't be the case with jitter present.

"Steve, Isn't Metrum Octave a NOS DAC? I would need reclocker for best results with AE."

Yes, but you need a reclocker with upsampling DACs as well for best results with AE. They all benefit significantly from low-jitter sources.

"Many people go for NOS claiming ill effects of digital filtering (pulse response) but reclocker most likely involves digital filtering defeating purpose of NOS."

Depends on the reclocker. Older reclocking chips did have SQ impact, but the newer TI chip is really outstanding. I'll bet the DAC2 uses this one. Have not heard it yet.

Not being able to detect differences, even reviewers is quite common. All it takes is a typical active preamp and all of this will be masked in noise, compression and distortion. You will not hear the difference betwen AIFF and .wav for instance.

Steve N.
Empirical Audio

Thanks, Steve. I'm committed to wireless network but will wait few years to make big step with new DAC (and possibly reclocker). It looks like D/A chips improved but also reclocking chips and analog electronics are making big steps.

Kij - if you are waiting for another beter reclocker chip, you will wait a long time, maybe forever. I seriously doubt if TI has another on the drawing board and nobody else seems to be playing anymore...

Steve N.
Empirical Audio