Putting together a new Roon network music playing system for portable & demo

[JonMarsh]

well, geez, it's a new year, and I haven't finished configuring and tweaking my last music player setup (AURALiC Aries with Mutec 1.3+ and AURALiC Vega DAC) and I'm already working on another one, a combination of pieces I've bought in the past and some new bits (pun intended) that should fit together fairly well, from what I hear, and give me an opportunity to tryout Roon as well.

Given the concept that a picture is worth a thousand words or more, (especially on the internet) let's get the pictures rolling.


microRendu with sonicTransporter.curio by Jon Hancock, on Flickr


Lacking as I am in adult supervision (aka "wife"), whenever something really intriguing comes along, I have an unfortunate tendency to let my enthusiasm get the best of me, if the possibilities lead to more and better tunes-- all the more so, if it leads to utilizing something that seemed very necessary at one point, and which has been judged by a host of reviewers to be "best in class" (Berkeley Alpha USB to AES interface), but which due to dropping using a Mac or PC as a music server, has been somewhat under utilized...

Anyway, the item sparking my enthusiasm this time is the Sonore microRendu-

microRendu-top by Jon Hancock, on Flickr


And the reason Sonore came to my attention at all, is due to a friend's interest in the PS Audio DirectStream DAC, and the review by Ted_B on CA for which he was very impressed with some aspects of the amount of detail and balance in the DirectStream's rendering- but it was like a 4K image with the color saturation turned way down- for him, it just didn't reach any kind of real musical nirvana, UNTIL,

A few weeks ago I got a call from a good audio buddy, Jesus R of Sonore fame. He wanted me to hear his flagship UPnP renderer, the Sonore Signature Rendu. It is an ethernet to SPDIF (or I2S-HDMI) converter/renderer. Sure, why not. A couple weeks ago it arrived and I hooked it up via BNC/SPDIF to my Chird Hugo. Hmmm...very nice indeed. (Note: Chris's review of said Signature Rendu is due out presently). The DirectStream, gathering a little dust while I decided how to write the review, was calling out to me "play me, play me".

Jesus is very proud of the work that went into the Signature Rendu, especially the very low jitter, very high quality I2S output (compatible with several pin-compliant I2S HDMI inputs on several different DACS, including the DirectStream.) As luck and irony would have it, the Rendu setup required me dusting off an old PS Audio P300 ac-generator to block some house-bound dc that caused the Rendu to drop off the LAN periodically (a fix that is coming soon, according to Jesus). After confirming that a P300-powered Sig Rendu was now rock solidly connected, I found a nice Nordost HDMI cable and entered the world of I2S (I can't tell you how many sources, format converters or DACs I've had in here that taunted me with this connection, but this was the first time I had input and output together in one room).

This began one Monday evening at 8pm. My first taste of this combination lasted, without wine-induced bathroom break or any other silly distraction, until about 3am in the morning. It was an audiophile's best dream, an audio lover's best attempt of heaven on earth, a contender for one of two or three best audio listening sessions of my life. Due to my well-heeled assumptions, I went from WTF to laughter (yes, I think I physically laughed out loud a few times; thank god no one heard me; they were all asleep) then back to WTF several times. The display analogy: not only had they turned the color and hue controls back on, the display became 3D (without glasses, thank you) and had the blackest blacks I'd ever seen. Again, sorry, but WTF! Why, with this input (Ted promised me all inputs were identical) would the DirectStream now explode into colors, tones, rhythms, clarity, absurdly accurate image density, and overall musicality that I've maybe never heard before. Why? Yes, the Signature Rendu is a clearly a special piece, but it needs a partner, and the DirectStream danced with it like they have been secretly practicing every dance style for 30 years.

So... this is NOT about the Signature Rendu- which may also reach it's ultimate synergy with the DS DAC due to the I2S interface they both have.

This is about the new, just released, barely shipping microRendu... which is also an ethernet network renderer, but to USB, instead. That would not normally get my interest, except that I have a Berkeley Alpha USB which would take that interface the step further to the DAC input I normally prefer to use. And which is compatible with re-clockers like my Brainstorm DCD-8 and Mutec MC3+.

Now, the microRendu brings some other interesting tricks to the party...

Selectable Output Modes

• Mode #1 - SqueezeLite Output - This output works with any Logitech Media Server and compatible controllers. This output supports true gapless playback of PCM and DSD/DoP.
• Mode #2 - ShairPort Output - This is an AirPlay emulator that utilizes streams sent to it from a compatible source. This output supports true gapless playback of PCM.
• Mode #3 - MPD/DLNA Output:
• Mode #3a - DLNA Output - This output utilizes streams from UPNP/DLNA servers and controllers. This output can be configured as an OpenHome renderer. This output supports true gapless playback of PCM, DSD/DoP, and native DSD.
• Mode #3b - MPD Output - This output is intended to work with a SMB mount. This output supports true gapless playback of PCM, DSD/DoP, and native DSD. This option requires a USB drive with your content in combination with the built in Drive Mounter application.
• Mode #4 - HQ Player NAA Output - This output utilizes streams from Signalyst's HQ Player running on your computer. Digital signal processing is performed by HQ Player and then asynchronously streamed to the Network Audio Adapter (NAA) output. This output supports true gapless playback of PCM, DSD/DoP, and native DSD.
• Mode #5 - RoonReady Output - This output utilizes streams from Roon. This output supports true gapless playback of PCM, DSD/DoP, and native DSD.

http://www.sonore.us

So this covers quite a few bases... and for those with USB DACs and happy with the performance of the USB inputs, your system will look simpler than mine. I'll certainly give the Vega a chance with it's own direct input USB, which is reputed to be quite good... for USB. :W

For me, I'm quite interested in how well it does with Roon, and in specifically trying out a Roon front end, with my somewhat eclectic and bizarre music collection- I figure it's worth a one year subscription to find out...

The microRendu just became available the beginning of May- I ordered one on the 2nd, and it won't arrive until sometime in June, after initial mailing list backorders have been filled.

The microRendu is available without a power supply and with several power supply options- it needs between 7 - 9V, and the quieter the better, at 2A max. I'm tempted to design and build one, but given the cost of time, I'm even more tempted to pony up later for the signature Rendu supply. That will cost more than the microRendu and the sonicTransporter combined.

Now, the microRendu is NOT a Roon server... and so I needed to find another hopefully low noise, fairly appliance like and flexible box to provide the server function- it wasn't a hard decision after looking around a bit to go with a Linux computer appliance that has a similarly flexible software stack, and in fact is a partner with Sonore and also resells the microRendu - this is the sonicTransporter from Small Green Computer.

http://microjukebox.com/products/sonictransporter?variant=18167842628

No fans, no Windows, not desktop OS at all, just a Linux music server with software options. (my NAD M50 does the same things, but doesn't have the software options....

Here's a picture of the sonicTransporter sitting on top of my 12" Macbook. Yeah, it is dinky enough to make a Mac mini look like a workstation in comparison.

IMG_2846_DxO by Jon Hancock, on Flickr


Most of the other bits I already have on hand, in fact purchased for other experiments not yet engaged, so I have a brand new Airport Express and a suitable Netgear Gigabit switch.

The Alpha USB is worth a few pictures and words on-

Alpha USB 1 by Jon Hancock, on Flickr

It underwent a long, rigorous development process with many delays beyond when Berkeley initially thought it would be released- as they worked through issues to make sure the noise isolation between stages was as high as possible, even going to the extent of special ferrite absorbers in the communication between the USB receiver and the clock and AES/SPDIF output. The USB async clocks were also the subject of considerable development effort and refinement through many design iterations.

Alpha_USB_inside by Jon Hancock, on Flickr

I have a couple of iPads I can use as the controller, and of course we can run the software on our iPad Pro's, too.

The only system review I know of online is not yet complete, only Part 1 of two, at Computer Audiophile. It's worth a read if this kind of configuration is of any interest to you...

http://www.computeraudiophile.com/content/698-sonore-microrendu-review-part-1/

How does it sound? well, this comment from Chris at the end of Part One seems to be the money quote:

Before heading off to the Super Bowl of audio shows that is Munich High End, I'll leave readers with this listening impression - I've spent hours on end listening to music since I took delivery of the microRendu. I wanted to make sure I wasn't burned by expectation bias, so I compared it to many other sources and methods of audio playback (both blind and sighted). After all this, I can unequivocally say that with the microRendu in place, my audio system has never sounded better than right now.

Consider that his audio system has seen many very high end server setups- including several Aurdender models... and he's discussing this in the context of a system that uses the Berkeley Alpha USB and the Berkeley Alpha RS DAC for digital conversion to audio.


BTW, I have NO connection, financial or otherwise, with Sonore- I'm just passing this one because I suspect it's going to be an interesting build and an interesting listening experience, between Roon, the sonicTransporter ($375) and the microRendu ($640, plus power supply- see web site for options- I'm starting with the IFi version).

[ergo]

This is a very interesting solution it seems. Thanks for sharing.

Berkeley is interesting in a sense that they have many resellers in US and 'World' seems to cover everything but Europe. There appears to be no resellers in Europe at all... wondering what is up with that.

[JonMarsh]

I think it's the CE and ROHS thing... I don't believe their products are ROHS, just like mine aren't. I own an Alpha DAC (on loan to Stephen Manning right now) and the Alpha USB. If I hadn't gone off the deep end investing in test gear, I'd likely be owning the Alpha RS DAC by now, too. Or at least be able to say I've listened to it at length at the Berkeley dealer where I've bought their stuff. It's the only one on the market that I've been seriously interesting in how it compared with my TotalDAC, considering a really high end perspective, not a bang for the buck perspective like the Vega or Yggdrasil.

The problem is that ecologically, we should avoid lead, no question. Don't eat it, drink it, or put it in the ground where it originally came from or anywhere else. But as regards the physical and electrical properties of solder, a good quad eutectic lead/tin/silver/copper solder beats any ROHS tin based solder hands down across the board on a variety of properties, especially long term stabilty- the tin solder is very brittle in comparison, and known to be prone to growing whiskers. My favorite solder hands down for manual work is Cardas Quad Eutectic, which fortunately I can still purchase in the good old US of A.

In the USA, aerospace/military/high rel data com does NOT use ROHS solder. For these very reasons. Same with me. :W

(OK, I'm not exactly sane in this area, having worked 5 years for a mil-aerospace power supply company before joining my current employer...) (and due to a variety of interactions with customers of my current company on quality and reliability topics, I'm still reasonably up to date on these issues...)

Yes, I'm thinking this new batch of hardware has some interesting flexibility and capabilities- one thing I didn't mention is the several software stacks that support DSD over DOP and native DSD through this setup, if your DAC does. That's not an issue for me at this time; I've yet to see a DSD DAC that has the true EBIN (equivalent bit input noise) to compare with the state of the art in PCM (and yes, that judgement includes the PS Audio DirectStream DAC) and I'm yet to be convinced that my 44.1 CD's sound better up sampled to DSD than played direct with my TotalDAC or up sampled to 1.5MHz in the AURALiC Vega. But never say never until you've listened.

I do intend to get a Yggdrasil some time this year, and my friend in Munich is still considering the DirectStream, though after pointing him in the direction of the Mola Mola equipped stands at the Munich High End Show last week, I think he may be diverted, because he heard some very good things- including a speaker company's products whom he was quite familiar with, and knows the owner, and which sounded much better this year- only change was Mola Mola Makua preamp and their DAC.

http://mola-mola.nl/index.php/ct-menu-item-2

http://mola-mola.nl/index.php/dak

from last year:

http://www.digitalaudioreview.net/2015/05/manger-s1-a-high-end-active-from-munich-high-end-2015/

So who knows....

Should be an interesting year, this year... on so, so many levels!

[JonMarsh]

Woo Hoo, Santa came in May- and it was a surprise!

Given that there was a big mailing list of people signed up to buy these, and I didn't get in on the ordering action until Monday morning (review was posted and ordering was open for those on the mailing list to Sonore on the 29th)-- I was surprised and pleased to get another package today! This one had the microRendu and the iFi power supply.

Nothing is real without pictures, so without further adieu...


IMG_2849_DxO by Jon Hancock, on Flickr


Now, this is a pretty good phone picture- but it doesn't convey how ridiculously small this thing is... maybe this next one, with an iPhone 6 in the picture, will...

The USB looking plug adapter is a "direct connect" part to hook the microRendu up to the DAC without any additional cable.


IMG_2851_DxO by Jon Hancock, on Flickr


The funny thing, of course, as I somewhat expected, is how much bigger the power supply is...

IMG_2856_DxO by Jon Hancock, on Flickr

This puppy is claimed to have only 1uV of wideband noise on the output.... gee, I wonder if anyone I know might be able to measure that... main problem is it's riding on top of 7VDC. The AP can resolve 1 uV, but it expects it to be at or near 0 V. Hmmm... :W

[Steve Manning]

Jon, what would be interesting to see is a side by side of the Gungnir multi-bit and the Yggdrasil

[JonMarsh]

well, the AD5781 is used in the Gungnir; that's an 18 bit R2R DAC. The AD5791 is used in the Yggdrasil, which is a 20Bit DAC, and as far as I know they're using it in a sign magnitude configuration which yields 21 bits effective resolution. They may be doing the same thing with the AD5781 in the Gungnir, I just don't know. The multibit option for the Gungnir I've heard referred to as a Yggdrasil Jr, which probably is a fair description. The logical question, of course then, is how much junior?

No question, $1349 is cheaper than $2299. With CD material, they might sound very, very similar, as long as the slight glitching which the 5791 has isn't any worse in the 5781.

If someone wants to send me one to test, that would be interesting; obviously I would listen to it, too, but I think I would hold out for the Yggy= I have a lot of high res stuff of one sort or another...

[wkhanna]

i have a standard Gungnir & hope to be getting the Yiggy in the near future.
i have considered the multi-bit upgrade for my Gungnir, but i think for my needs/wants, in the end, the Yiggy would prove the better value overall.

both units are/will be at Jon's disposal for testing.

[JonMarsh]

Two points-

There are some very specific concerns and discussion about the Yggy, which I will summarize shortly here- one reason detailed measurement would be interesting- including with the high resolution scope.

Second, I've got a plan mapped out for starting the setup of this system this evening- hope to have it running pretty soon, since getting the microRendu earlier than expected... It's all about scheduling and time management these days!

[JonMarsh]

Pretty much there now...

Spent my lunchtime going through the cables, plugging stuff in, powering up, and configuring via my Macbook Pro.

• Plugged in and powerd up Alpha USB first, becuase the microRendu needs to see a USB device at the output for configuration and playback
• Configured the new Airport Express, setting up a separate wireless network and a hard local network via a Netgear 5 port Gigabit switch - which was the next step
• Plugged in the microRendu and the sonicTransporter next, ethernet to the Netgear switch, and powered up.
• Went to the sonicorbiter site, which brought up the two local devices for configuration- the sonicTransporter and the microRendu
• Configured the microRendu for playback using Roon
• Switched to the sonicTransporter configuration - selected the Roon server software, AND most importantly, after having plugged in my external USB SSD, selected that drive as the mounted music folder
• Then, having already installed the Roon controller software on my iPad Pro, started that up, and connected to the local Roon core on the sonic Transporter, then signed in to the Roon Account I had setup with the initial trial and first years purchase.
• This started the process of loading and cataloging all the albums and tracks and artists, which is going on as I write, with the counters for each along with lyrics and reviews, and bios and images counting up in the status line..
• Then hook up the output of the Alpha USB to the AES input on the AURALiC Vega, and connect the Vega to the Taurus Pre via balanced cables (had some short Cardas Golden Presence cables that worked fine.)
• Then, when you power up the DAC and preamp and you don't get any sound, go back and check all the cables, and then check and hit the switch on the Alpha USB which MANUALLY selects between coax S/PDIF and AES XLR input.
• Advance the volume gently with your Audio Technica headphones, or be prepared to have your ears blasted off....

See? Easy peazy... Not! Well, not if you're just used to hooking a few boxes together, hitting the power switch, and turning up the volume. Thats just not how a customized high performance high flexibility and relatively low cost music server works these days-

But I gotta say, from the very short exposure so far, I think Roon is going to be giving a lot of competitors the Schiits... it is pretty cool, and it adapts and does interesting stuff with your own music collection. This is going to appeal to a lot of people, because it's like being on a well designed web site, where the feature attraction is your music collection and all the interesting stuff behind it...

We're up to 700 albums and rising... this takes a bit of time. I'm not sure how much of the special Roon data is stored on the SSD in the sonic transporter (200MB) versus on the iPad... suppose I should figure that out someday!

[wkhanna]

But I gotta say, from the very short exposure so far, I think Roon is going to be giving a lot of competitors the Schiits... it is pretty cool, and it adapts and does interesting stuff with your own music collection. This is going to appeal to a lot of people, because it's like being on a well designed web site, where the feature attraction is your music collection and all the interesting stuff behind it...

the Stereophile review i read last year on the Roon gave me the impression of it being a system that would not be obsolete soon or give one buyer's remorse down the road.
but at $500 for lifelong membership, it makes it hard to justify for us economy-minded music junkies with 5 TB running for free via Foobar.

still, there is no denying the excellent feature set offered by Roon.
i would like to have it, some day......
i would like a Devialet 400 someday, too..... ; )

[JonMarsh]

Yeah, and I'd like a Model S or Model X someday, too....




But today, I have this... pretty sweet on my 12.9" iPad Pro, spent a little more time bopping around the interface and "discovering" cool stuff about my music collection. This is going to make it MUCH more accessible and interesting to GF... and selling it to GF is a good thing.

IMG_0447 by Jon Hancock, on Flickr


Now, here's how I see it... if you're spending this much on hardware...

• sonic Transporter $375
• microRendu $640
• iFi power supply $75
• Berkeley Alpha USB $1495 then, now $1890
• AURALiC Vega $3400
• Mutec MC3+ $759
• USB SSD for music storage $400

Then $119 for a one year trial of Roon is not at all out of the question; I'll concede that I'd want some experience and confidence before plopping down $400 or so for a lifetime membership. But considering what subscription software costs these days that brings me a lot less pleasure, it seems pretty fair... and so far it seems like it's very well run and put together, in the way they support their products.

The big drawback of many music server products is being "stuck" with just one OS for music organization and serving. This little combo with the sonicTransporter and microRendu offers far more options- (most of which I'm not interested in, but which are popular with a variety of people) - just showed it to GF, as she got back from her morning rounds, and I think she's sold...

[JonMarsh]

Burning down the house (well, just burning in the player...)

Running this new setup in some more with program.


IMG_2866SS by Jon Hancock, on Flickr


IMG_2870SS by Jon Hancock, on Flickr


At some point soon I should do a tidy up on the cabling, but want to integrate the Mutec3+ and rubidium standard next. Also must admit I'm quite curious about the upcoming Mutec 10MHz standard, especially in comparison with the SRS standard packaged for audio.

Now, I can imagine someone, anyone, in fact, (GF or otherwise) saying there sure do seem to be a lot of fiddly bits here, compared to just plugging in the dedicated CD transport I have sitting around on an adjacent shelf, and pushing those funny round disks into its maw. Well, (apart from the fact that it won't play high res audio), it just does't sound as good- in fact, I've done quite a bit of listening to the Cambridge disk transport through the two AURALiC pieces (Vega and Taurus Pre), and through those relatively new AT headphones of mine, I just wasn't feeling the loving, to use the currently popular vernacular...

OTOH, same cuts, ripped with XLD on my Mac, ported over to a nice little OWC 500GB portable SSD, plugged into the sonicTransporter and the rest of this setup, NOT yet with re-clocking, I'm feeling a lot of loving.... only difference is the front end and the inputs used (CD transport uses S/PDIF, Alpha USB I'm using AES/EBU, as is my preferred practice.

Currently playing, "Six String Theory" with Lee Ritenour and guests (such as Joe Bonamassa, at the moment... very nice!)

[JonMarsh]

Star date 2016-05-15:

Added my two Mac Pro's as Roon controllers, both the 2010 running Windows 10 and the 2013 running OSX- can do all the same stuff for the Roon server in the family room as the iPad, just without getting up from my desk and finding the iPad- adding albums to the Queue, immediate play, reading the "liner notes" and reviews, and in general wasting far too much time and enjoying it immensely...

This is in a completely different class from any other playback solution I've used. Roon is the glue that can tie many different pieces of hardware and playback technologies together, and allow a user to move from a single box solution on a desktop computer or "HT computer" to a distributed processing architecture that seems very efficient, responsive, and flexible.

Oh, and this sounds pretty dang good, too! To a considerable extent, just how good it sounds is going to depend on what you have connected, but I'm very inclined to say that the micrRendu and how it connects to USB will not be the limiting factor- and likely if you want to get the best performance possible out of a USB connection on a DAC, you'll want to look into a microRendu.

Looks like my Munich friend will be purchasing a used signature Rendu, if things go right, which will get shipped to me first to test out and try in the system here- it outputs to S/PDIF and I2S, so I could actually set it up as a different playback zone, and connect it through the Mutec3+, for example, then to the TotalDAC.

Then I could move the microRendu to a different room physically, or keep it just for the "test/demo" system and headphone use. I'm liking this kind of flexilbity...

[wkhanna]

i certainly hope Dan (PewterTA) is paying attention to this thread.
as mentioned previously, i was impressed with what i red about Roon from the Stereophile review.
after your reports i am just about sold.

next, i will need to fan the fires of Dan's interest and get him to implement the product into my system (he is the IT guru, i am just a nuts & bolts guy :W )

[JonMarsh]

Then I imagine dropping some strong hints Dan's way might be a pretty good idea!

I'm not much of an IT guy either, but it all went together fairly easily using the web based configuration tool- select which software support mode for the microRendu, and which for the Sonic Orbiter. You don't have to use a sonicOrbitor with this- any configurable server that will feed a network share point in various modes will work. Sonore has links to the basic setup manuals, and there is a sponsored forum with all the different configuration possibilities setup as separate support threads on Computer Audiophile.

Now I have my 12" Macbook also setup as a Roon controller, and this morning I got word from my friend in Munich that he closed the deal on the signature Rendu, and it will be shipped to me shortly.

Testing both and switching between them should be quite easily, if I can setup both simultaneously as different zone outputs, and then choose which one I want active by any of the Roon controllers; I can have them drive the same Mutec as a format converter and re-clocker, and then drive which ever DAC I want to use for testing (midrange: Vega; upper range, my TotalDAC). I'm just not sure about whether the signature Rendu is compatible with Roon as a network renderer- otherwise I'll have to setup an MPD server of some sort. the sonicOrbitor can do that, but I don't have any intention of switching from Roon on it. Of course, I could just get another one, as the price is certainly right, but still- $400 to support testing a platform I don't intend to use is not the way I'd want to go.

At some point I should get the signature power supply for the microRendu, but let's keep things in perspective- that is $1399, and my friend found the signature Rendu for $1650. So, I think he's making a good move, especially since he's interested in trying it with a PS Audio DirectStream, and they reportedly have great synergy working together (some reviews suggest that without the Signature Rendu and the I2S interface, the DS just really isn't all that special... )

[pbelo]

I want to move to digital path, so have my music libray converted into Flac uncompresed files + my downloaded DSD files in x2 , x4 , x8 formats , DSD 128 , 256 , 512 .

Planning to link HDD with files to SonicTransporter then Micro Rendu to DAC.

Now I have CD player linked to Krell preamp by balanced XLR and then to Krell amps by balanced XLR also.

1) As DAC thinking on Ifi micro DSD or next Ifi DSD Pro able to read DSD 512.
Can the 2 RCA outputs of this DAC able to drive the Krell amps without preamp ?
Can we convert RCA to balanced XLR or not ?
Or do I need another DAC for this with balanced XLR outputs able to drive Krell amps ?

thanks for yr comments to my doubts

kind regards from Portugal

[JonMarsh]

I have been so busy at work I don't always get to all the forum sections- glad you PM'd me, that was the right thing to do. But for everyone else, my response:

I think you will enjoy your front end quite a bit. But let me say, my personal experience is that the only DACs that successfully drive direct to the power amp at all playback levels are ones that manage the volume control function with a separate analog control, without attenuating digital data, like the Cambridge 851D, or the Metric Halo ULN8, for example, in my own experience. Using digital attentuation is not the best path, especially if you listen often at more modest or reasonable playback levels. I say this based on experience with several DACs having carefully implemented digital volume controls, and finding they always sounded best with a high grade preamp ahead of them-

Berkely Alpha DAC
TotalDAC D1 Dual
AURALiC Vega

Of course, you can always try it without a preamp first-

Personally, I've found in the majority of cases I much prefer using a balanced preamp and amplifier inputs- many balanced amps or preamps really sound best only in that mode, becuase of how they derive internal signals from single ended inputs. But this is the sort of thing where individual assessment is the only sensible path- I can only speak from experience in a few brands. I am also likely biased in my opinion becuase of my prior experience in professional audio and designing that type of equipment, and having a full grasp of the compromises and difficulties going single ended and having to use "ground" for signal returns. I haven't had an unbalanced system path most of the last 30 years, just occasional components from time to time. It is true that for some components with balanced inputs it's just a receiver function, but that still helps in reducing the EMI/RFI issues between components.

[pbelo]

Thanks Jon,

Have this option for DAC - PREMAP , PD2 from Physon Audio , by the specs what do you think ? analogue volume ...

http://www.phisonaudio.dk/home/

thnaks for feedback

Pedro

[JonMarsh]

The volume control is of a type that is my 2nd favorite- a multiplying DAC used as a programmable attenuator. This is good. (my most favorite is using a variable gain line stage such as the Mola-Mola preamp or Ayre KX20.)

Now, this has a DAC built in.. The data regarding the DAC section is somewhat minimal- obviously, supports DSD, and claims high stability crystal oscillators and rechecking of input data, but not how, and not by what reference source. (I like rechecking, but with very specific types of oscillators- there are some oven controlled crystal oscillators that are competitive with Rubidum as regards low phase noise, but I don't see anything like that here). In the end, the only thing that really counts is how it sounds in your system, eh? Compared with how a DAC can be specified, and what data should be provided, the specifications are rather bare... one might go so far as to say, threadbare!

Any technical reviews on the web? OK- I downloaded the manual, and their are more specs of a sort, there, such as the DAC chip used, the AK4490, which is another 32 bit delta sigma architecture part, with a lot of DSD functionality.

My question for you might be, what is the majority of your digital signal program source? DSD? PCM from CD? High res PCM? The reason I ask is that this should guide the direction of your choice. I've got a huge, HUGE library of PCM material- both standard and high resolution - and some SACDs. For me, I tend to favor high grade R2R ladder DACs with bit perfect digital filtering (closed form) and value highly the best possible performance with CD resolution material. That's why I have a TotalDAC D1 Dual and why I've been testing some other R2R ladder DACs for friends that can't muster that level of expenditure. Someone really into DSD and with a lot of program material should find a DAC like this interesting- but being built into a preamp is cost effective, if it meets your needs, but not so much, if it doesn't. For example, what if you tried out a Signature Rendu paired with a PS Audio Direct Stream Digital, (as one of my best friends just has), and decided that was the cat's meow? Then the built in DAC is not so useful anymore, unless you put the preamp in a secondary system. Or just say, well, that's the breaks- it's still a great analog preamp (presumably). BTW, any test reports on this? Is it a great analog preamp?

Now, as to my own SACD disks, I have a special setup for ripping the DSD and during ripping converting to 176 kHz 24 bit PCM- this works fine for me, and allows me to archive and use my SACD program on my current digital setup. This is probably not a "purist" approach, but I enjoy the music just fine...

Here is a review of the PD2- are you familiar with it?

http://www.6moons.com/audioreviews2/phison/1.html

They use some techniques I have in the past with good results, such as the folded cascode and using virtual ground operation of the linear op amps to remove common mode issues from the distortion signature of the input stage.