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Chord Dac 64

katana100

Standard Member
Hi,

Anyone used a Chord Dac 64 with either an Arcam Alpha 9 CD player or a Toshiba sd-900e? Any comments as to performance?

Thanks

K100
 

Nic Rhodes

Well-known Member
I haven't heard it with either of these player but it is a very good DAC. It is not the best I have heard but it deals very well with SPDIF sources.
 

katana100

Standard Member
Thanks; what is the best DAC that you have heard? Also, forgive my ignorance but what is SPDIF?
 

Nic Rhodes

Well-known Member
The Best DAC I have heard is the Audio Synthesis. SPDIF is the interface that connects a transport / CD player and the DAC. It is HIGHLY flawed and is the reason many DACs have gone out of fashion. Special techniques are needed in the DAC to get around this. Chord uses a buffer, Audio Synthesis doesn’t use SPDIF!
 

alexs2

Well-known Member
Hi...the Chord DAC64 is an excellent dac,but also worth hearing is the Perpetual Technologies P1A and P3A upsampler and DAC.
Together this provides a superb digital source with the upsampler providing CD inputs upsampled and interpolated to 24/96 level.
Admittedly not quite as good as proper DVD-A or SACD sources(but those are difficult to find)and this will work with any CD.
I've had mine now for 2 years,with no problems.
This,to my ears anyway(and many reviewers also)is getting pretty close to the dCS upsampler and DAC costing £10K,so not a bad bargain for about £2K.
There is a UK importer,but I cant remember it offhand....also have a look at www.av123.com for info.
 
Y

Yummy Fur

Guest
I would agree with all the above comments. I think there is a certain element of 'synergy' between Transports and DAC's. So I think it's vital to try to listen to the DAC's with any intended Transport.... I don't think it's necessarily a case of 'best' Transport plus 'best' DAC = best result...

I think SPDIF is an abbrviation for Sony Philips Digital InterFace..

Yummy Fur
 

katana100

Standard Member
Hi All,

Thanks for the advice. I have done some reading into the Perpetual Technologies P-1A and P-3A and most of the reviews seem very postive. What do people think about investing £2k in these products? Would I be better off waiting a year and spending the money on a good DVD Audio/SACD player instead?

Regards

K100
 
G

GaryG

Guest
Do you think the timing and jitter performance of the CD players you are considering would be suitable for use with the DAC's your are considering? Just a thought.
 

katana100

Standard Member
I thought that these products were meant to deliver significantly better performance with ANY non-highend systems (in which category I would place my Alpha 9 CD and Tosh SD-900)?
 

michaelab

Novice Member
If you stick a Chord DAC64 (or even a Tag DAC20 like I have) onto the end of an Arcam Alpha 9CD you'll get a very significant improvement.

The jitter issues with SPDIF and outboard DACs can be solved with a good clock recovery DAC. The Tag DAC20 and the Chord DAC64 both fall into this category and make the jitter problems of SPDIF irrelevant. The DAC64 has probably the best solution yet to the problem which is to use a RAM buffer to store the incoming digital stream which can then output the data with absolutely perfect timing - jitter is totally eliminated.

Also, Yummy Fur, good DACs are pretty transport independent. The difference between a good transport and a bad one is the amount of jitter introduced. Since, as I just mentioned, good DACs can get rid of the jitter then the quality of the transport is not important. Even the cheapest transport will still read the digital data correctly and with a good DAC that's all that matters.

Michael.
 

Nic Rhodes

Well-known Member
Originally posted by michaelab
If you stick a Chord DAC64 (or even a Tag DAC20 like I have) onto the end of an Arcam Alpha 9CD you'll get a very significant improvement.
yes I think you might

Originally posted by michaelab
The jitter issues with SPDIF and outboard DACs can be solved with a good clock recovery DAC. The Tag DAC20 and the Chord DAC64 both fall into this category and make the jitter problems of SPDIF irrelevant. The DAC64 has probably the best solution yet to the problem which is to use a RAM buffer to store the incoming digital stream which can then output the data with absolutely perfect timing - jitter is totally eliminated.
I am not sure I agree with this. Both of the above products have good / excellent jitter reduction circuits (the Chord being the much better of the two) but jitter is NOT eliminated. There are inherent limitations to what can be done with SPDIF. The best anti jitter solutions eliminate the SPDIF altogether. Tag adopted the sink link for it's players to improve on the PLL solution in their DAC. It is MUCH better. PLL are inherently limited by what they can do but are a double edged sword.

Originally posted by michaelab
Also, Yummy Fur, good DACs are pretty transport independent. The difference between a good transport and a bad one is the amount of jitter introduced. Since, as I just mentioned, good DACs can get rid of the jitter then the quality of the transport is not important. Even the cheapest transport will still read the digital data correctly and with a good DAC that's all that matters.

Michael.
Michael

I am not sure I agree with this either. Paul Miller published some very interesting results on DACs and transports a while ago. The synergy was not just down to the jitter issues. All the transports were 'low' jitter but had substantially differeing results.

My best DAC was transformed when I replaced my own 'hot rod low jitter' player with the dedicated Transport. Both are very low jitter but the differences were night and day. I think this is the point GaryG was eluding to as he has a similar DAC.
 

michaelab

Novice Member
Beekeeper, I would suggest that a RAM buffer DAC (like the DAC64) is totally jitter free and transport independent. I don't see how it could be otherwise.

I hope we agree that any cheapo transport can read the digital data correctly (ie 11001010 will get read as 11001010). Given that, the only issue is jitter. A RAM buffer DAC is effectively reading the digital data and re-recording it into RAM. The RAM buffer is then used as the source. This certainly makes it transport independent and any jitter there is would be what was introduced between the RAM buffer and the actual DAC chip (none I would guess).

Taken to (admittedly ridiculous) extremes a RAM buffer DAC could read the entire CD into memory first and then play it back with the transport switchd off. The digital data stored in memory would be identical regardless of the transport and at the point the transport would be the RAM buffer itself. The DAC64 is just doing this process on a streaming basis but the results should be the same.

I agree that the Tag DAC20 is not as good as that, and it's PLL cannot eliminate jitter totally but they do a very good job. I've tried my DAC20 with my Marantz CD50SE (my usual transport), a cheapo Pioneer DV-350 DVD player and a Sony Discman portable (via TosLlink) and I could not tell any significant difference between them.

Michael.
 
G

GaryG

Guest
K100

Do you have either of the players you mentioned, or are they a shortlist for a future purchase?

If they were a shortlist of players you were thinking of buying and then adding a £2k DAC, sonically, it may be better to look at a single box solution at the combined price of the player and DAC where the digital bitstream has been optimised.

Alternatively, if you plan to invest futher funds at a later date then a top notch DAC now would be a good investment with an upgrade to a dedicated transport later on.

Irrespective of the jitter/timing arguments put forward, a decent dedicated transport, sonically, *WILL* outperform the digital output of a CD/DVD player. You might want to keep an eye on the Classified's section of the Hi-Fi World magazine, bargains do occasionally pop up. If you ever see one of these: www.audiosynthesis.co.uk/transcend.htm at a sensible price you should snap it up immediately.
 

Nic Rhodes

Well-known Member
I think much of the argument has been done already and is in here if you can separate the wheat from the chaff, good luck!!

http://www.avforums.com/forums/showthread.php?threadid=31891&referrerid=15820

It only gets interesting on page 5 onwards!

Originally posted by michaelab
Beekeeper, I would suggest that a RAM buffer DAC (like the DAC64) is totally jitter free and transport independent. I don't see how it could be otherwise.
It is a good solution but not perfect. Jitter comes in many different forms, how do you deal with PSU induced jitter. The buffer may overcome many of the SPDIF limitations but this is not the whole story. Much is discussed in the above article.

Originally posted by michaelab
I hope we agree that any cheapo transport can read the digital data correctly (ie 11001010 will get read as 11001010). Given that, the only issue is jitter. A RAM buffer DAC is effectively reading the digital data and re-recording it into RAM. The RAM buffer is then used as the source. This certainly makes it transport independent and any jitter there is would be what was introduced between the RAM buffer and the actual DAC chip (none I would guess).
010011101010 are always the same. What about out of band signals saturating input digital receivers, RFI, signal reflections from non standard connectors, ground plains, earths, amplitude, time and frequency domain info?. Don’t forget every DVD / CD player has RAM buffers currently, it is just the Chords is bigger than most. Meridian has it’s FIFO and ROM drives. They still have measurable jitter. It isn’t significantly measurably lower than most other methods, just a bit better.

Originally posted by michaelab

Taken to (admittedly ridiculous) extremes a RAM buffer DAC could read the entire CD into memory first and then play it back with the transport switchd off. The digital data stored in memory would be identical regardless of the transport and at the point the transport would be the RAM buffer itself. The DAC64 is just doing this process on a streaming basis but the results should be the same.
RAM buffers are a great solution, don’t get me wrong but they are not perfect. What we are essentially describing is a computer. They aren’t to hot a cd replay from memory are they? Even the best of these (Linn?) is not a patch on their dedicated player. It is not a new solution either, every player has buffers currently, they get too easily confused most of the time! If it eliminates jitter don’t you think everyone would be using this wonder techniques rather than just 2 companies?

Originally posted by michaelab

I agree that the Tag DAC20 is not as good as that, and it's PLL cannot eliminate jitter totally but they do a very good job. I've tried my DAC20 with my Marantz CD50SE (my usual transport), a cheapo Pioneer DV-350 DVD player and a Sony Discman portable (via TosLlink) and I could not tell any significant difference between them.
PLL are easy to implement, and are reliable but they leave loads to be desired. They do essentially guarantee latching on to signals but additional measures are needed for ‘quality’ jitter reduction. All your examples are limited by the SPDIF, no wonder they sound similar! Seriously, just reclocking your CD50 will yield MAJOR benefits with the TAG. Look at the Tricord clock3 / Digital Interface Board for REALLY BIG gains. I have done loads of Marantz from this era (inc 50s) and they are simple to do with MASSIVE GAINS. Worth a look IMHO. More info in the long link. I think I might even have an old clock 2 around if that is of any help to you?

Things are not all they seem in the seemingly simple world of 1 and 0s!
 

katana100

Standard Member
Gary,

I have both the transports that I posted initially. The reason that I was thinking of the DAC was exactly as you stated - I could upgrade the procesing side first and invest in a good transport later. Apparently, the Perpetual Technologies P1A reduces jitter and is meant to compensate for the shortcomings of the transport.

Does a one-box solution avoid the problem of signal degradation between transport and DAC?

Regards

K100
 

Nic Rhodes

Well-known Member
Originally posted by katana100
Does a one-box solution avoid the problem of signal degradation between transport and DAC?
yes, this is why DAC have died a death. It is why Tag are binning off their nice DAC at about £400 as opposed to £1200. Single box solutions eliminates the SPDIF. Both Gary and I use DACs that do NOT use SPDIF ( but can). Instead we use a system that minimises jitter and have probably the lowest jitter of any system on the market. They still have a little jitter but it is really low and even difficult to measure at these levels.
 

michaelab

Novice Member
RAM buffers are a great solution, don’t get me wrong but they are not perfect. What we are essentially describing is a computer. They aren’t to hot a cd replay from memory are they?
Well, they are actually. December's HiFi News reviewed a product called the Sonica from Midiman (www.midiman.co.uk) which basically adds an SPDIF output to any PC or laptop with a USB port.

The reviewer (David Allcock) ripped a bunch of CDs to his PC and then "spent numerous hours just enjoying a mix of these various tracks, and being utterly stunned that in every aspect the PC with the Sonica matched my Sony DVP-S7700 transport."

He was using a Perpetual Tech. P-3A Signature DAC. He goes on to say "The Sonica gives you an idea of what Peter McGrath and Ken Kessler heard when playing CDs from a hard drive...with a suitable integrated amp., speakers and a good DAC such as the P-3A or MSB Link DAC you have an easy to use system delivering stunning sound quality and flexibility." (Italics are mine).

I will investigate the Trichord upgrades if they're not too pricey.

Michael.
 

michaelab

Novice Member
Also, the Tag DAC20 is out of production and was being sold off cheap (how I got mine) because it's been superceded by their AV32R AV processor.

In that sense DACs are as alive and well as ever, it's just that they're now just part of an AV processor that does a lot more.

Michael.
 

CJROSS

Well-known Member
Hey Katana, your query whether Int. CDPs are better for jitter between transport & DAC would seem logical, but Im convinced that you get good & bad cases, the level in Jitter in a lot of CDPs exceeds what is present in many CD/DVD transport + DAC combos, if a CDP has had fundamental design incoporated to hinder jitter then it should be good for this, here is one such player Ive spotted recently :

http://www.creekaudio.co.uk/products/cd53.asp

With a new customised ultra low jitter master clock and extra circuitry to reduce jitter from the Digital signal Processor, the CD53 truly sings. A re-clocked, low jitter, transformer coupled, co-axial and optical digital output makes it possible to fully realise the potential of high-end stand alone DAC, provided the correct type of interconnect is used.

To provide a useful upgrade path, the D to A converter, high quality master clock generator, jitter reduction circuitry and regulated power supplies are sited on a separate printed circuit board that can be removed and replaced by new or emerging technologies in the future


But even saying that, this player did not get a glowing report in HF+ for its playback abilitites, the reviewer was not that enamoured with it, don’t get me wrong if you want a stop gap now before getting a DAC this would be perfect : with a view to adding a quality DAC later. When it comes to transports you should be looking at the best connection type that you feel is adequate for your needs. I personally find SPDIF RCA coaxial is fine for me (although I can see though why the upper echelons of the hifi public like XLR Balanced connections though and the like), saying that there is big variation in types of cable used in RCA cabling IMHO, Im currently trying out a barrel load of cables from one of the DAC dudes on the HFC forum, and surprise BeeKeeper one of the best ones Ive heard is 27p/m Sat Coax cable with heavy duty Locking RCAs ;) . But one thing I would agree with is the Trichord mods (Im unable to do so due to using my DVD transport the DACs cannot be reclocked Ive checked) especially the clock 3 & Digital output board upgrade £385 fitted by Trichord this IMO is a no brainer and one that Marantz CDPs owners should consider (Micheal http://www.trichordresearch.com/cd_player_upgrades.html
: DOB upgrade). As I say the use I have for my DVD transport is 90% music / 10% DVD Movies & Music so this is unable to me at present hopefully adding this to DVD willm one day happen but the DVD player clock frequency is not easily changed.

Btw Michael I seen that a review in HFN for that midiman USB SDPIF connection, again a confusing and not wholly descriptive review IMO : Is it a toslink or RCA SDPIF connection you get on that little box, because it sure looks like a toslink connector to me from the photograph. If so I find it hard to believe that it outshone a S7700 Sony in transport duties (im happy to be convinced otherwise BTW)

Katana if it were me dude (and it aint its you) I would be using the Tosh SD900E into a suitable DAC that could go up to 48Khz minimum, this gives you access to lots of material that a normal CD transport like the Alpha 9 cannot access, ie DVD Video tracks encoded either as 16/48 PCM or as DD 5.1 surround sound again at 48Khz (This sounds surprisngly good IMO downmxied into stereo via a PCM signal fed into a good DAC) I also believe that your 900E is 24/96 capable via its digital output, again 24/96 DVD Audio material may be available via that particular units output (IIRC) if the DVD Audio industry ever get their finger out and include stereo mixes for the DVD Video owning fraternity, just another facet of why DVDs make great transports IMHO.

Good thread dudes !! ;)
 

CJROSS

Well-known Member
Originally posted by michaelab
Well, they are actually. December's HiFi News reviewed a product called the Sonica from Midiman (www.midiman.co.uk) which basically adds an SPDIF output to any PC or laptop with a USB port.

The reviewer (David Allcock) ripped a bunch of CDs to his PC and then "spent numerous hours just enjoying a mix of these various tracks, and being utterly stunned that in every aspect the PC with the Sonica matched my Sony DVP-S7700 transport."

He was using a Perpetual Tech. P-3A Signature DAC. He goes on to say "The Sonica gives you an idea of what Peter McGrath and Ken Kessler heard when playing CDs from a hard drive...with a suitable integrated amp., speakers and a good DAC such as the P-3A or MSB Link DAC you have an easy to use system delivering stunning sound quality and flexibility." (Italics are mine).

I will investigate the Trichord upgrades if they're not too pricey.

Michael.
From the Sonica spec sheet Michael, no mention of any RCA connections, so again my views on the reviewer hearing a difference from his Coaxial output on his S7700 Sony (if he used it that is) comapred to a toslinked connection off the Sonica does fill me with doubt TBH. :

- USB-to-S/PDIF Optical Out and 1/8" Mini-Analog Line Out
- S/PDIF Optical Out can transmit Linear PCM, AC-3, or DTS
- Sonica supports the following output formats:
• 24-bit Linear PCM
• 16-bit Linear PCM
• 16-bit AC-3 over optical connector
• 16-bit Dolby Pro Logic over optical connector
• 16-bit DTS over optical connector

An inetresting product none the less bro. Again though an incomplete review, I think the connection type is quite a big part of a output section or DAC review.
 

michaelab

Novice Member
CJ, the Midiman Sonica has a TosLink SPDIF output. I'm almost tempted to get one just to check it out. For £79 you can't really go wrong. Sounds like a great product for the HTPC guys.

I've looked at the Trichord upgrades but as I live in Portugal I can't send my player away to be done do I'd have to do it myself. I'm pretty handy with electronics and a soldering iron so maybe fitting a DOB wouldn't be that tricky. I'll see if Trichord will send me the fitting instructions before I decide.

Since the DAC20 has an XLR balanced digital input it sounds from the Trichord site as if I could add an XLR output to my CD50 - that would be cool! (allthough I have doubts as to how much difference balancing can make in a digital interconnect).

Michael.
 

dave48

Active Member
As an alternative approach, playing back from a PC hard drive through a Pro Soundcard (such as M-Audio 1010) can sound pretty d**n good. And theoretically this all but eliminates jitter issues.

What bugs me is why it sounds so much better after 11:00 at night! I know the electricity supply is supposed to be cleaner, but all my neighbours are trying to get some sleep ....

Dave48
 

Nic Rhodes

Well-known Member
Originally posted by michaelab
Well, they are actually. December's HiFi News reviewed a product called the Sonica from Midiman (www.midiman.co.uk) which basically adds an SPDIF output to any PC or laptop with a USB port.
:(

Sony spent £250k on their version and dropped it as a dead duck.

Re PCs playing this stuff, computerare the worst jitter offenders I have seen to date, even with the quality cards, Taking a SPDIF output is horrendous, internal sound card is better but if they think they are better than a dedicated system they are talking a complete load of rubbish. I have even done my own 'jitter optimised' card but it is like ****ing in the wind with computers, the RF / PSU is just so dirty. It just doesn't work, that is why no serious player uses it.
 

dave48

Active Member
What is the point of using the S/PDIF out on a decent soundcard? The D to A converters in decent pro soundcards are pretty good - it would seem moderately counterproductive to plug in an external DAC to a pro soundcard. Better just to use the (balanced) analogue outputs.
 

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