Airpot Express - Upgrade amp or DAC?


I have a pair of KEF Q300s running through an Audiosource - Amp 100, fed by an ethernet wired Apple Airport Express. I'm running uncompressed AIFF files via iTunes.

What's my next updgrade, a DAC or amp? In comparing the Airport DAC to my Yamaha RX-V1900 DAC, the Airport sounds awful. I'm definitely leaning towards a DAC, but I wonder if people have other suggestions.

Regards,

Andrew
rooty-j
Your problem is the AE, and no DAC will fix this. I know because I have modded the AE in the past for customers and developed several types of reclockers to make it sound good, including the Pace-Car and the Synchro-Mesh.

The Synchro-Mesh is the best way to make the AE sound good IME. What it does is reduce the clock jitter of the signal from the AE by establishing a new master clock. Jitter makes the audio diffuse and unfocused. The SM inserts between the AE and the DAC or SS receiver.

The digital source and the master clock inside that is the most important thing in any digital audio system.

BTW, the Sonos is another option to the AE. Most people use Sonos. It will not play hi-res but neither will the AE.

Steve N.
Empirical Audio
This is not accurate. DAC will improve AE since it has relatively low jitter on digital output but horrible jitter artifacts on analog out. You can find measurements here:

http://www.stereophile.com/digitalprocessors/505apple

Any jitter suppression, either by reclocker or upsampling (reclocking) DAC is always beneficial.
+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? :)
It sounds like you have done some critical comparisons already and have idenified a system weakness that you know can be improved. I would follow that lead and get a DAC that you know something about or have heard. The audition is always the single best advice you can get.
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
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.
"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
Steve, who makes reclocker with this new TI chip?
Kij - I do.

http://www.audiocircle.com/index.php?topic=106328.0

I dont know whats inside of newer Big Ben or other reclockers like Monarchy. I used to mod the Big Ben and the Monarchy DIP years ago.

Steve N.
Empirical Audio
Thanks Steve. It looks interesting.
Steve N (Empirical) - In your 1/13/13 post, you said that you'd done comparisons of various sources, including the AppleTV. How would you rate AppleTV vs the other computer sources and in general vs run-of-the-mill DVD players? Thanks.
Steve, would it a better solution to stream music to a 2nd/3rd room to a laptop hooked up to a USB dac. Hence cutting the Airport/AppleTV out of the equation.