Part 4 of 5 : Symposium Main Listening and Equipment Comparison Session

[cfmsp]

"My point is that this magic box also has to be good!"

 

John Swenson is a world class engineer, and I have no doubt that his implementation is quite good. The audiophile community is lucky to have him share his efforts on line, esp. considering the inevitable crackpots (who think they are in his league) trying to denigrate his work, just because it goes against their preconceived notions.

 

clay

 

[vortecjr]

your going off on a tangent. I am happy to have John here and I trust he is every bit (hehehe....sorry ca humor) that you say he is.

 

Its not an implemination its a brain fart....its already been done!

 

 

Now, I due support and believe in the advantage of the "implemination" as in the transport and psaudio dac. However, the cheaper "impleminations" like the squeze box and the nmts just dont sound that good and yes they are based on the "implemination". I call them magic only because they seem to due so much and its not a put down. So my point still stands....they have to be good!

 

[The Computer Audiophile]

Hi Everyone - I unpublished a few posts here because they were getting a bit off topic. I love the discussion, but not in this thread. I was unable to just move them into another spot on the forum for now.

 

Clay - Don't worry about posting links to Audio Asylum etc... It's a very established site and I certainly don't mind getting more info to the readers here.

 

[Forehaven]

I just wanted to say what a fantastic and thoroughly thought out demo, and I agree, it's one of the best I've ever been too. Chris and Maier are really nice guys who know a hell of alot about computer audio as a side! Despite me not being in the industry, and one of the less knowledgable persons in attendance, they covered material that I understood, and showed the obvious, to me, the different sounds of each system. I agree with an earlier post that the G5 and Matins systems sounded best. Along with the Amarro software, the audio was much more natural and analogue sounding. I too was impressed with this software, not to mention it's audio ripping aspect I saw in the vinyl to digital conversion room.

 

Great going Chris, Maier, Keith Johnson....seeing inside a studio was awesome!, John and James from Sonic Solutions, the Sooloos gentleman I'm forgetting his name, and lastly, Thanks for the high quality of equipment that made it possible to hear the differences in the setups.

 

Chris Glanton

 

[cfmsp]

 

 

Chris,

 

you had no way of knowing this, but.... the off topic discussion on this thread (i.e. the John Swenson separate boxes idea) would eventually have proven to be 'on topic' for a Symposium thread, inasmuch as it's just been revealed on AA that the Matan Server IS an implementation of such.

 

http://www.audioasylum.com/forums/pcaudio/messages/5/55446.html

 

If you'd like, I can start a separate thread on this.

 

cheers,

clay

 

 

 

 

 

 

[usernaim250]

Sounds like an interesting demo and great weekend, but I can't help wishing the demo was done blind, or at least part of it done blind. A lost opportunity.

 

[vortecjr]

know if the Martan server people have a website?

 

[tmfidelis]

During the beta testing for Amarra, we did implement a variant of blind A/B testing @ my testing facility by having individuals enter the room not knowing the playback condition. we played music and made a change. The unknown change was switching the software I/O. Then we made a second change. This too was a software I/O change, and so forth. The listener would write down the playback numbers and then define which ones they preferred and why.

 

Your suggestion to place a blind fold over the eyes is quite valid but some individuals prefer to listen with the eyes open and nothing around the head. Some listeners did close their eyes during pre-testing.

 

The results were consistent using various DA convertors and a plethoria of Mac computers, Mac Book Pro, Mac Mini, Power Mac G5 2.0, Power Mac G5 2.7, and Mac Pro.

 

Regards,

 

Maier Shadi

The Audio Salon

Los Angeles, CA

 

Timothy Marutani

MARUTANI CONSULTING

OAKLAND, CA

 

[Brucemck2]

Maier/Timothy -- Based on those "sighted but blind" tests, what was the ranking/conclusion?

 

[tmfidelis]

@ brucemck2:

 

We received overwhelming conclusive results indicating Amarra to be the preferred software I/O.

 

We also forgot to mention that some testing involved delivering systems to our beta test sites outside from our facilities and visited other Sonic beta test sites.

 

Again, all the comments are subjective but implemented scientific methods to configure the computers. We standardize the drives, SLC SSD, enterprise HDDs, and two Thecus N7700 NAS drives, raid 5 and raid 1. We also configured the OS in a consistent manner, Tiger and Leopard.

 

Computer configuration will be compiled and released by Chis in a timely fashion.

 

Please note we are not saying the software is a "one size fits all" solution. The overall playback system development should always be taken into consideration.

 

Regards,

 

Tim/Maier

 

 

 

 

 

[manisandher]

Can anyone confirm whether the Model Twos were using HDCD @ 24/176? (For those of you who were there, there should have been a blue 'HDCD' light lit up if HDCD was engaged.)

 

Mani.

 

[Purite Audio]

Mani Hi, I would really like to hear your model II at some point, I almost bought one ( long story ) a few years back, I don't believe we are too distant, regards Keith.

 

[tmfidelis]

We forgot to mention we had the listeners leave and re-enter the room for another set of A/B listening.

 

Regards,

 

tim/Maier

 

[audiozorro]

I may be interpreting this wrong but I thought that the HDCD light only comes on when you are playing HDCD material. I believe the HDCD on my DVD player only comes on for instance when I am playing one of the Reference Recordings HDCD discs. If I play a 24/96 disc, the 24/96 light is lit but not the HDCD light.

 

Thus I use the DAC in the DVD player, which has digital I/O, to determine whether audio files ripped from HDCD discs to my computer and played back are bit perfect. If you have a DAC whose HDCD light comes on when it is playing high-rez 24/96, 24/176.4, or 24/192 audio files that do not have HDCD encoding, then perhaps not all HDCD indicator light parameters are the same.

 

[manisandher]

My question wasn't with regard to whether the playback was bit perfect or not. It most definitely would have been - these guys know what they're doing!

 

No, I was asking because I know of another Model Two user (who posts on another site) who does not use the unit's HDCD functionality when recording at resolutions > 16/44.1 - he prefers it without HDCD at these resolutions. I just wondered whether the 'creators' of the Model Two used the HDCD functionality at 24/176 during the recording sessions. I'm assuming they did, as KJ uses it for the 24/176 RR files. But it would be good to know for sure.

 

Mani.

 

[manisandher]

I'm sure we could arrange this.

 

My wife and I are currently in the middle of a house move - will let you know once I have everything set up again.

 

Mani.

 

[Bodyslam]

There seems to be a little confusion on this point, and why shouldn't there be? Originally the blue light only came on when a playback unit detected the HDCD flag in a 44.1/16bit bitstream. Then after a couple of years Pacific Microsonics changed it so that the HDCD flag exists in the output of the Model Two at all sample rates and all wordlengths that it will do. And since then the Model Twos and anything else that detects the flag also lights up the light at any resolution. So for several years now the blue light has not indicated encoded 16 bits, it has just indicated that the unit detects the flag.

 

So two points: One, not all of the files that may have been played at one time or another at the symposium were recorded through a Model Two, but most were, including the ones that Keith recorded on site. Those that contained the flag lit up the blue light.

 

Two:your comments about some user of the Model Two not using HDCD functionality at higher resolutions doesn't make sense. When encoding to 44.1/16, there are a couple of options for fitting the 24 bit source into the 16 bit delivery format. The user may use one or the other or neither, operator's choice. But at any setting of 88KHz or higher those options are not even available. You've got a Model Two, Mani, check it out for yourself. There are no options for turning off any so-called HDCD functionality. Unless you count turning off the flag sensing on the monitor input, which has no effect other than changing the blue light to yellow.

 

[manisandher]

Hi Paul,

 

Thanks for your explanation. I will check things out for myself when I have a spare minute (hopefully early next week).

 

Paul, did you consider also using an analog master (i.e. tape) as a reference against which to compare the various computer-based setups? A/B comparisons with the reference could have been made really easily, helping to evaluate which computer setup comes closest.

 

I'm just curious as to why this wasn't tried...

 

Mani

 

[Bodyslam]

Well, it was up to the organizers, not me, but I thought that having tape would distract from the purpose of the event, which was to share information about the approaches and strategies that people have tried in server design. As it was, we could have used twice as much time for that discussion.

 

[audiozorro]

That is perhaps the only criticism I would have of the Symposium. It needed to be twice as long, even it required vendors to sell their products to support the event. I would imagine a 4 hour morning session of presentations and demonstrations, 1 hour lunch, and a 4 hour afternoon session of workshops, sales, discussions and social/professional/hobby networking.

 

I wish I could have attended and I would guess that no one wanted to leave. I hope the Symposium was a financial success and that there will be a Computer Audiophile Symposium next year.

 

[ted_b]

Buy some space at the Hyatt Denver and run a Symposium during RMAF (or directly before/after). You'll get a number of the industry folks already there, and would be a great draw for us RMAF'ers. Separate ticket, of course.

 

[tmfidelis]

Dear Mani:

 

FYI - as 2/3 the research legs for the symposium, we always reference digital playback to tape and The Tape Project.

 

Regards,

 

Maier/Tim

 

[manisandher]

Paul,

 

I'm confused!

 

I'm aware that 'Peak Extension' and 'Low Level Extension' are not available @ >16/44.1.

 

I'm assuming that the 'HDCD flag' to which you refer is the process explained to me by Mark Donahue:

"... the HDCD process alerts the PMI filter chip in the DA converter that the material was created with an AD converter with a known anti-aliasing filter and noise shaping curve. The PMI filter chip can then utilize a reconstruction filter optimized for the specific AD converter used for the creation of the master. This process is invisible to all other DA converters and the HDCD dither/noise shaping is considered to be the dither of choice for high resolution material."

 

Paul, are you suggesting that this process (or HDCD flag) in the Model Two cannot be turned off when recording an analog source at resolutions > 16/44.1?

 

Mani.

 

[manisandher]

tmfidelis,

 

So, which computer setup comes closest to the analog tape???

 

Pray tell...

 

Mani.

 

[tmfidelis]

Dear Mani:

 

The references have been ongoing comparisons over years. I must revisit the comparisons with the aid of others to give you a clear and precise answer. Comparisons using the tape as a reference greatly aided to verify turning off terminal services in Windows based machines was definitely a correct procedure. Referencing tape playback also made it clear SSD are presently the way to proceed.

 

 

Regards,

 

Tim