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First multi-channel DSD playback solution with Mytek!


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How about sitting in your listening position, browsing jremote, and pulling up a pure native 5.1 DSD rip of Beck-Sea Change, for playback in native DSD. And no, I don't have a Sonoma workstation sitting here! YES!!

 

Well, I mentioned in a few threads that I was getting ready to prototype a possible 5.1 pure DSD playback setup. The thought of using J River and jremote to browse a multichannel catalog that includes native DSD 5.1 (and 3.0, etc) is a 2013 goal of mine.

 

Well..today marks the first huge step in that goal!

 

Mytek delivered my third Mytek Stereo 192 DSD DAC yesterday, along with a simple 4-port USB hub. My goal for this weekend coming up was to simply get something working, and I assumed it would be a lot of trial and error..even though Michal and Chebon (Mytek) had given me pretty good instructions going in.

 

Matt at J River had just released a beta version of JRMC that fixed a couple idiosyncrasies in 5.0 vs 5.1 playback, so i downloaded 18.0131, made sure Mytek's 133.1 Windows ASIO driver was loaded on my CAPS V2+ and hooked up the USB hub. I used some decent (and awful generic) USB cables to cobble together a three-port setup, and used the SOtM card to drive it (directly powered by the iFi). I thought the hub would need power but it didn't. The USBPAL driver screen indicates what goes where (hint: the oldest serial number gets main lf/rf, the next gets c/sw and the newest DAC gets ls/rs). I guessed right the first time! Go figure.

 

I use a tried-and-true analog multichannel preamp (Sony TAP-9000ES) for volume and analog channel trimming (so far done via ear only; I will drag out the Rat Shack digital SPL meter tonight). I created a MCh DSF parent folder, moved a few 5.1 DSF albums into it and had J Remote add the parent in auto-import. Voila. (My next step is to create a multichannel view and use it in jremote; the view rule will be simple..."channels greater than 2"). One of the DSF folders is the Pentatone sampler that includes test tones and channel id tracks.

 

First up, after confirming channels and doing simple trims, was Beck-Sea Change, a tremendous surround sound album. The clarity, tone, dynamics and deep bass of this thing, heard 1000 times before, was startling. The Mytek trio blew away (yes blew away) the Oppo 83SE in this first test. And channel trims weren't even done yet. Wow!

 

Stay tuned for more updates.

 

Here's what the setup looks like (stacked Myteks next to my CAPS V2+. The other thing is simply a gigabit ethernet switch, so my 2 channel setup would still have ethernet).

 

[ATTACH=CONFIG]4092[/ATTACH]

 

Ted, congratulations. I have spend a lot of time fiddling with non conventional, all digital, multi channel signal paths myself and this is hard work, but very rewarding. Few questions / comments.

 

First, how exactly does it work? Specifically, how does the 5.1 DSD bitstream get split in 3 x 2 channel? Does it? Or do all three Myteks receive the exact same signal from the USB hub? If so, how does each Mytek know which two channels to play? What is happening in Mytek firmware, JRiver, and Mytek Jriver drivers respectively to make this work over USB. Would it work with a PCM signal as well? Right now MCH PCM on a server requires MCH (usually Lynx) AES/EBU output card. Could this now be done over USB as well (at least for 6 channels)?

 

Second, my experience suggest that format (i.e. being able to play native DSD) makes a substantial difference and all else being equal native DSD will beat PCM conversion any day of the week. However, in audio, all else is never equal, and format is just one of many factors determining sound quality in the chain. For example, by playing in DSD, you cannot use the digital volume control in Jriver. In my experience, having to insert the Sony MCH analog preamp at the end of the chain to do volume control will totally wipe out the benefits of being able to play DSD. This is not a theory of mine, this is based on using both MCH analog preamps (i.e have used EMM Labs Swithchman, Theta Six Shooter and McCormack MAP1) and well implemented digital volume controls. If instead of a CAPS 2.0 you had a very powerfull processor(the CAPS 2.0 would choke on this), converted your DSD to PCM at 196/24 in JRiver, and used the JRiver volume control, this would in my estimation sound better than what you are doing now. There is one interesting alternative you could try. Take out the Sony, and calibrate the Front / Surrounds and Center volume levels with the Mytek volume setting. Then calibrate the Sub with the Volume control on the Sub. Next control all three myteks with the Mytek remote control. As long as all three myteks consistently pick up the IR signal this should work and will beat the crap out of using the Sony preamp (again based on my experience).

 

Third, using native DSD means you cannot use any other of the extensive DSP capabilities in JRiver (in addition to volume control), including EQ, Bass Management and Delay. For many, the benefits of having access to this would trump the benefits of staying in the DSD domain. Again, CAPS 2.0 need not apply because the server is way short of processing power to do this.

 

I will be able to weigh in this shortly based on my own expiriments. While I will continue to run all MCH on my modded Oppo (3 x S/PDIF digital out), for two channel I will be moving to running Dirac Live on a server, USB into the DAC (away from AES/EBU into a Trinnov processor). This will allow me to compare native DSD streaming, with PCM conversion and applying DRC. Will be interesting. While my conclusions will not necessarily be valid for other systems / rooms (in particular, the benefits of DRC will vary by room, and the SQ gap between DSD streaming and PCM conversions will vary by DAC), this will add another datapoint to the intersting debate. I know many purist dismiss the notion of applying DRC right of the bat (I used to be among them), but my ears tell me otherwise now. Again, I also hear clear benefits of DSD streaming over PCM conversion, so this will be a trade-off.

 

Keep up the good work and keep us posted.

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First, I am not technical enough to say what the ASIO driver is truly doing behind the scenes but it is obvious that it is the traffic cop for the channel mapping. Looking at the ASIO in and out, the channels are mapped there (and I knew ahead of time that it maps based on DAC serial number, so I ran my cables as such, and guessed right). Each DAC only deals with its channel pair. For 3.0 RCA Living Stereo extractions I'm not sure if the third DAC even sees a signal...dunno. will try later.

 

I see. So this is Mytek proprietary driver software. I believe this also answers the question asked in a previous post; It will not work with non Mytek DSD dacs.

 

I have no need to do any DSP, and I believe my lowly TAP-9000ES is as transparent as I need for this application. No, I don't use it for 2 channel...but I do use a two channel preamp for that setup (I've posted ad nauseum about Mytek's bypass vs remote volume, and about my Concert Fidelity CF-080). Do I have the best cables and power cords in this cobbled together setup so far? No. But once all the bugs are worked out I will begin to assess what i need.

 

I have not read on your Mytek bypass versus remote control experience. Unless you think the Mytek volume control sucks, I would give the Mytek direct signal path as I suggested a whirl. You can also get a MCH preamp build using the TAP modules. I believe you have a TAP passive - try it on two channel against the Sony, if it is a lot better, get a MCH version build. I looked into this myself at some point. My bigger point is you are losing a tremendous amount of information running through a set of analog cables and the Sony analog preamp. I have used much better preamps than the Sony (EMM Labs Switchman) and they compromised SQ significantly.

 

Edit: you are exactly right on the CAPS V2+ horsepower; it wasn't meant for DSP or maybe even multichannel. My plans are to build a very simple more powerful CAPS for multichannel..not sure what is though. But I don't think I want my 2 channel setup always going through a USB hub, and yet I want my multichannel setup to use the SOtM if possible. So that means a second mch CAPS.

 

I'll probably end up needing a CAPS 3.0 Zuma for my applications.

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Erik,

I found the volume control in the Mytek (and in most, not all, remote volume DACs) to be quite compromised (vs bypass mode) even compared to something like the Sony analog preamp. Also, the Sony gives me 5.1 HT bypass (i.e sending fronts, center and sub from the AVR that processes 7.1 HDMi movie soundtracks using separate amps and speakers for sides and surrounds) and multi-5.1 source selection (probably not long term as I won't use the Oppo analogs anymore). BUT, I hear ya when you say that a mch Bent TAP would be nice....it's tough enough to find another one, though, let alone two more. And John is doing less and less with parts lately i think (and I'm not DIY). I am floored that an EMM Switchman was compromised.

 

Ain't it fun. ;)

 

Fun indeed. May be the Myteks don't drive your poweramps directly very well. I compared the Switchman behind my EMM Labs DAC2X for analog volume control against using the Trinnov processor before my DAC2X doing digital volume control. It was no comparison. Switchman was sold within 24 hours. The Switchman is a fine preamp, but in my experience there is no preamp like no preamp.

 

You can still buy all the components from bent audio to build a multi channel stagleformer based volume control. Not cheap in components alone, and then you need to find a technician to put it together for you.

 

BentAudio.com :: TAP

 

For single ended operations, another option for very transparent MCH volume control is daisy chaining three placette audio units.

 

Anyway, you're probably focused on getting the digital side of things sorted out and worry about volume control later. All I am saying is with the Sony preamp you have a lot of SQ upside if you do find something better.

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.......Channel gain can be finessed, I believe, by setting up each DAC using the VC knob to set level for both channels and a BAL function to trim between them.....

 

Trimming channels can indeed be done quite easily between the three 2 channel DACs, expecially when they have L/R balance.

 

..... Then the remote control or jRiver would increment +/- from the settings maintaining the original differentials......

 

I don't think the JRiver digital remote control can be used with DSD, so master volume control is an issue. You can put an analog preamp behind the whole chain, or synch up volume up/down steps between the three DACs. If all three DACs correctly pic up the IR signal 99% of the time this should work fine.

 

I am having the same issue synching up volume control between my 4 channel Trinnov and 2 channel DAC for surrounds that bypasses the Trinnov. I am now using Bel Canto as extra DAC, and synch up using iRule. However, the Bel Canto misses so many IR signals it gets out of synch all the time. So I just bought an NAD M51 DAC with RS232 for my surround channels and hopefully keeping Trinnov and DAC in synch over RS232 works better.

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I won't tell all the details... But why wouldn't it? With computers, we don't have to consider any limitations in processing power, do we? :) Of course we'll optimize it to run as fast as possible, but Moore's law will take care of the rest.

 

To my knowledge there are no DSP engines that run in native DSD and offer bass management and EQ. Digital volume control in DSD, yes, at best delay. That's it.

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I have my own DSP engine capable of all that.

 

So it appears my assessment that it is not currently "available (i.e. to the general public)" is correct.

 

So if/once I have bass management it will most likely be available for both. Now it's not available for PCM either.

 

What do you mean? Bass management for PCM is available everywhere - an a PC, Mac, in univeral players and processors.

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