Airpot Express - Upgrade amp or DAC?

Kijanki - have you ever actually listened to an AE through a DAC??

I have made measurements and critically listened to many digital sources, including AE, Transit, Tascam devices, Apple TV, Squeezebox 2, 3, Duet and Touch, Sonos, Lynx cards, RME cards and others.

The standout worst of these is the AE and Sonos. No DAC will reclock these enough to make it musical except maybe the PWD in NativeX mode. Silly to drive such a DAC with an AE...

The jitter reduction capablilities of 99% of DACs is dissappointing IME. You are better off to reclock the source if you intend to use a high-jitter source. This is cheaper than buying a really expensive DAC and works actually better.

If you read the last 10 reviews of DACs in TAS and Stereophile, you will find that they often use an Off-Ramp to drive them to determine the performance with a low-jitter source. TAS concluded that even $1K DACs can sound as good as $8K DACs if a low-jitter source is used.

Steve N.
Empirical Audio

Yes, I use Benchmark DAC1 with AE and sound is incredibly clean up to point of being too clean. You might not like sound of the Benchmark DAC1 or any upsampling/oversampling DACs but cannot deny its jitter suppressing ability. Measurements taken by few reviewers, including Stereophile, confirm it. In fact all the measurements of Benchmark DAC1 are phenomenal.

http://www.posthorn.com/Bench_5.html

"You might not like sound of the Benchmark DAC1 or any upsampling/oversampling DACs but cannot deny its jitter suppressing ability."

It is an okay DAC at this price-point. I modded the DAC1 for almost 10 years, but I dont mod anymore. I have a lot more experience with DAC-1 than you do. I completely redesigned it in my mod including replacing the clock with a Superclock, op-amp swaps, eliminating several op-amp stages and lots of power supply changes. I even put I2S interfaces on many of them. There are probably 100 of my modded DAC-1s out there still in use.

I can give some anecdotal evidence for the stock unit:

Both my testing and reviews I have read demonstrate that each of the digital inputs sound different and changing cables or sources makes a difference. I am not saying that jitter is not reduced, because it is, but because it is a resampling DAC, you hear the jitter of the clock in there. The PLL is also affected by jitter, so jitter on the incoming signal does matter, the lower the better. This is the common thread with most DACs and this one is no different. There are only a couple of DACs that are truly jitter-immune and they sound like the internal clocks, which is not always a good thing.

IF you buy stuff based only on measurements, I am sorry for you.

Steve N.
Empirical Audio

+1 Kijanki. And the AE can sound superb if you kill the jitter. I'm using a Z-Systems RDP 1 between my DAC and the AE and the results are surprisingly good.

That said, one you buy a DAC, your amp will be the limiting factor. Isn't this hobby fun? :)

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

Effects of jitter are not even detectable buried deep in -130dB noise floor according to many different reviews. PLL on DAC1 is used only for the syncing while main reduction of the jitter is obtain by reclocking in asynchronous sample rate converter. Perhaps I don't have as good hearing as you but my Benchmark sounds identical with different sources. It sounds a little better with different op-amps (tried few) but even original NE5532 (TI) sounds pretty good, unless you had earlier version of this amp (thin sounding) made by Signetics before their factory burned down in 2001. TI version has different (larger) die.

Original question was about choice between upgrading amp or DAC. Choice is quite easy since AE has 2400ns peak to peak jitter on analog output and respectable 258ps peak to peak jitter on digital out.

According to Benchmark Media technical director John Siau DAC1 was not designed to sound warm but natural. He stated that warm sound (enhanced even harmonics) does nasty job on instruments (like piano or percussion) with harmonic structure more complex than simple overtones. Piano might even sound, on overly warm gear, like out of tune.

Benchmark DAC1 is very clean and revealing making many systems sound bright. That was the case with my previous speakers that had aluminum dome tweeter. Hyperion HPS-938 I use now are perfect match for the Benchmark and Rowland class D amp. Not only that it sounds perfect to me with extremely clean sibilants and amazing details but also because of AE I don't have to play games with expensive playback programs, computer speed, amount of RAM memory etc.