Alternate Hardware for Audiophile Mac Server

[Dean358]

Greetings All,

 

Having recently joined Computer Audiophile I’ve been enjoying the forum posts. I’d like to share an alternative hardware configuration for a Mac based server I haven’t seen discussed here:

 

About five years ago I decided to try a build a Mac based music server. My goal was to have the sound quality equal to that of my Wadia 270se CD transport. The only output I needed from the server was digital, ideally in AES/EBU format.

 

I started with a M-Audio USB to S/PDIF interface. Even with external clocking the sound quality wasn’t close. I then moved to a Lynx Studio Technology AES16 card. This was much better – lots to be said for having the interface card sitting on the bus -- but the sound was still thinner than playback from the Wadia. I experimented with this for some time, but grew frustrated when Lynx hadn’t released a PCI-E version months (years?) after Apple went to that bus. (I needed to upgrade the Mac.)

 

I then switched to a two-channel version of Apogee’s Symphony system. This consists of: a Symphony 32 PCIe interface card sitting on the bus inside the Mac which connects via Apogee’s propriety bus to an X-Symphony interface card sitting in a Rosetta 200 A/D and D/A converter. The software driving all of this is Apogee’s Maestro driver, which supports all core audio applications, including iTunes and Peak.

 

I use the A/D section of the Rosetta for hi rez capture from my vinyl front end and the Rosetta’s AES/EBU output to feed the rest of my playback system. External clocking is from an Apogee BigBen. At 44.1 KHz I’d say the quality is very comparable to the Wadia and at hi rez it’s better. Being pro audio gear it’s extremely stable and fairly bullet proof.

 

Total cost for the Symphony hardware and software is around $4k, not counting the external clock. While not cheap that’s not crazy by audiophile standards. If you’re considering building a Mac based audiophile server I recommend you listen to this configuration.

 

Cheers,

Dean

 

 

[The Computer Audiophile]

Hi Dean - Welcome to Computer Audiophile. Thanks a lot for the post. The more configuration options the better. It's really nice that you've compared your music server sound to your former reference, the Wadia transport. I'm not making judgements on the transport rather it's extremely helpful to have a reference for comparison. Otherwise you don't really know if you're getting better or worse sound that you could achieve through other means.

 

[ciamara]

Dean,

 

I like your approach. Apogee is one of those love 'em or hate 'em names in pro audio (more love 'em than hate 'em, I think). They are certainly very well liked by a lot of engineers. Their converters are definite step up from those provided in Digidesign's flagship interface (i.e. the 192 I/O), and in fact, some mix engineers use Apogee cards inside Digidesign's hardware along with Pro Tools.

 

Without question, the Symphony system is a phenomenal recording system. The Analog to Digital conversion process is solid, and the bandwidth afforded to those recording multiple channels at high rez simultaneously is truly impressive. I would love to hear some of your vinyl transfers.

 

Those that love the sound of Apogee's higher end converters describe it as clean, up front, punchy and well-defined. Those that prefer other converters complain that Apogee's sound is aggressive and lacking in fine detail. To each his own. I think you have chosen a very interesting route.

 

That said, if you ever get the itch, you may try other converters for 2-channel playback. More specifically, a Digital to Analog (DAC) converter connected to your Rosetta's AES/EBU output for monitoring/playback. From what I have been told, the D>A process is far more critical (i.e. susceptible to interference/timing issues) in a system than the A>D process used in recording. If you do elect to go that way, there is a wealth of information on this site to help guide you. Enjoy!

 

[ciamara]

I just realized you are already going AES/EBU from your Rosetta. What is receiving the AES/EBU signal? i.e. Which DAC do you use to get the results that you are enjoying? Does the Maestro software switch sample rates quickly? I had issues with the Maestro drivers when I had the Apogee Ensemble firewire interface, but that could easily have been an Ensemble-specific issue, so I am curious. Thanks!

 

[bordin]

Thanks for sharing, Dean.

 

Dean wrote: I then moved to a Lynx Studio Technology AES16 card. This was much better – lots to be said for having the interface card sitting on the bus -- but the sound was still thinner than playback from the Wadia.

 

My friend's reference transport is the Linn Genki, heavily modified, i.e. Superclock 3, OPA627BP, caps mod (Blackgate+Oscon), Phython PSU x2 (seperate digital & analog sections) & AES digital out installed.

 

This Linn transport sounds fantastic and aroud 20% fuller than using the Lynx AES16e in a PC. But the Lynx is on par with other well-known transport drives such as C.E.C.'s.

 

Given the amount of investment, the Lynx is very justified for a "hi-end" computer audiohile setup. The last 20% improvement may cost 5 times the first-level investment, but I also love to hear this last "mile".

 

Dean, would you be able to compare the AES out of the Symphony 32 PCIe interface and the Lynx AES16 ?

 

 

[Dean358]

Tnx Chris. Indeed, I find it’s easier to do subjective measurements / evaluations against a reference point. Great site, BTW!

 

Sanjay: For home listening I also prefer a sweeter sounding D-to-A converter than the Rosetta 200, even if that means the sound is less analytically “accurate.” (Big quotes there :-) My primary playback system signal path is: AES/EBU from the Rosetta into a TacT Audio 2.2XP room processor (time and frequency room correction) the AES/EBU outputs of the 2.2XP then feed two Wadia 27xi Dacs, one for low frequencies and one for mid/hi frequencies. The lo frequency Dac feeds the servo amps of Genesis 201 lo freq speakers and the mid/hi frequency Dac feeds an ASR Emitter II amp which drives the mid/hi Genesis 201 panels.

 

As for changing sampling rates: the PCI version of the Symphony system (for non-Intel Macs) had issues that resulted in the Rosetta needing to be rebooted often. That’s not the case with the PCI-E / Leopard OSX version and latest drivers – no problem quickly switching sample rates.

 

As the Tact processor uses 96 Khz/24bit internally I always feed the Dacs with 96Khz/24 bit signals from the Tact. Recently, I’ve also been experimenting with leaving the Symphony in 96Khz/24 bit for all playback material. This up samples 44.1Khz files to 96Khz before they hit the Tact and allows me to mix 44.1Khz and 96Khz files in iTunes without having to change sample rates. So far the playback quality seems really good – much to my surprise (I expected the internal up sampling in the Tact to be better than the Mac / Symphony.)

 

Bordin: You’re right – the Lynx AES16 card is a great value. As I recall, when I compared it (the AES16 version NOT the AES16E) to the Symphony system, the Symphony had a more focused sound stage, with more “air” around individual instruments and a more coherent sound. Overall I’d say the Symphony felt cleaner, and just made it easier to connect with the music. I suspect your 5 times cost / 20% better ratio is about right in this case.

 

Lastly, a quick note about my digital cabling scheme: I use Apogee Wyde-Eye AES/EBU cables. However I lift the ground at one end of each cable. This prevents noise and ground loops from being transmitted between chassis while maintaining the shield on the cable, thus preserving the integrity of the Eye pattern. Note than you can only do this with balanced signal paths, such as AES/EBU digital cables or 600 ohm balanced analog audio cables.

 

 

 

[ciamara]

I am intrigued that you have chosen to go with two simultaneous full-range outputs to low and mid/high frequencies. I presume your loudspeakers have internal passive crossovers, then, that allow you to use multiple full-range amplifier inputs without active crossovers. A neat approach -- certainly, one that would allow you to tweak your sound significantly. Those speakers actually remind me a lot of the Infinity IRS Series V. Ahhh ... the 80s.

 

 

[Dean358]

Please excuse my dumb comment above about using core audio (even with external clocking and the Maestro driver) to up sample to 96Khz. As several people around this site have pointed out, this is a path of darkness. I was working with a bunch of HiRez files when I tried this and didn’t really have time for critical listening. Yikes!