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Antelope DA Review


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My first Forum Topic post - be gentle. I hesitate to post/suggest equipment because everyone is different - but in the interest of science and sharing here is my latest experiment, motivations and results.


Firstly for my main music system I decided to make a Synchronous system - that is to say Lynx output clocked to the Alpha DAC (as opposed to an async system e.g. firewire DAC). NON of my comments here are relevant to an async system deployment.


If you assume that the playback system Amarra and Itunes output the correct samples at the correct time (a subject of another post) then the engineering of a sync. system to a DAC is dependent on the clock distribution (I have first hand experience of this in the design of various sync clocking systems used over long distances in telecoms). The clock distribution will be affected by the cables/impedences and crosstalk/emc etc..


Motivation: I wanted to remove (isolate) the influence of a very electrically noisy computer (MAC Pro).


Now although the DACs reclock and have various jitter rejection specs - I was influenced by a post by the Alpha DAC guys indicating energy transfer to the ground/power planes by a jittery source was a problem. The Lynx PCIe outputs a good source however the cable 1604 is the weak link ( I am aware of much higher quality replacement cables).


I read the spec of the Antelope DA which claims to receive an SPDIF or AES signal isolate the clock then 'reclock' the source through the 'thru' spdif/AES connecter.


So I experimented with the following setup: Macpro -> Lynx PCIe _> cheap (AES) cable (long cable) -> Antelope DA reclocker -> very good (audiophile) cable (2ft) -> Alpha DAC.


The PSU for the Antelope DA and Alpha DAC are isolated from the PSU for the MAC - so the only electrical connection between the MAC and the DA is the cheap AES cable.


I am delighted (astonished) by the results - Much wider sound stage, much better separation - really textbook stuff.


I then tested a Benchmark DAC (in place of the Alpha) again very good results. The difference between the Benchmark without the Reclocker and with the reclocker is larger - the difference for the Alpha DAC is less so but still apparent.


I also noted that before the reclocker setup my system would improve over time - as things warmed up - sometimes as long as 2 hours. With the reclocker the system works very well out of the gate - I conclude that my jitter (actually variation of jitter) calmed down as the system warmed.


I experimented with different cable lengths, and different grades of cable from the computer to the DA - no effect on the output. I experimented with poor cables between the DA and the Alpha DAC - wide variation of results.


So the DA reclocker isolated my computer source - cleaned up any jitter/variation of jitter and isolated the clock distribution problem to one 2ft audiocable (in my case a Harmonic Magic One AES cable) - the cable being short - good impedance charateristics/ shielded - The DA gives the DAC a fighting chance of doing its job (of course DACs vary in their conversion ability).


The reclocker also has the advantage of 'following' the output rate - so if Amarra plays a 192khz signal the reclocker will lock on to the new signal - this is different from clocking the Lynx card directly which would require manually changing the clock if sample rates of the song are different. (I considered the OCX to clock the Lynx and decided on the DA specifically for the isolation and physical seperation possibilities).


The reclocker also has the advantage that the computer can be a long way away from the DAC - I tried 20ft no problem - I haven't tried longer but I don't see any problems with longer 50ft+ cable lengths (within the spec of the AES)


I have every reason to believe that any reclocker would have the same effect although I haven't tried any others.


Although I would not now give up my Alpha DAC - in terms of marginal value/return: I would add a reclocker to a cheaper DAC e.g. Lavry/Benchmark before I would buy a 5k+ DAC.


Note: I have no affiliation whatsoever with any equipment companies etc...





Serious Listening:[br]Intel Mac Pro 6G (SSD) -> Amarra ->Alpha USB ->Alpha I Dac -> Ayre KX-R -> Tom Evans Linear Class A -> Avantgarde Mezzo Horns (107db) + Basshorns-> Engineered Room (Power, Traps, Helmholtz Resonators, Ceiling Diffusers)[br]Computer Listening:Intel Mac Pro 6G -> Lavry DA10 -> Adams S3A Active Monitors

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"I would add a reclocker to a cheaper DAC e.g. Lavry/Benchmark before I would buy a 5k+ DAC."


WTGOR I would suggest any dac is the sum of the parts..not just where the jitter comes from....the analogue output stage and it's implementation is much more impt in my book...a Benchmark/Lavry Da 10/11 will always sound like a Benchmark/Lavry Da 10/11, regardless of clocking and jitter - better but the same... IMHO etc etc


Clocking is only relevant in respect of spdif/AES/bnc/toslink connections ie where the data and clock signal are carried together. Asynch USB & FW do not. It's a little simplistic to say add a reclocker first. Not disagreeing with you just saying there are other considerations.


Best Wishes



Best Wishes


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Clearly the music playback system is a system. One could argue that the Room Modes are more important than the analog output system. Nevertheless the parts of the system matter.


My testing with the Lavry, the Benchmark and the Alpha DAC, is that the better the feed the better the performance of the DAC. Nevertheless the Alpha outperforms the Lavry which outperforms the Benchmark (which outperforms RME Fireface800, Edirol).


Subjectively my Benchmark plus Reclocker (total approx $2k) is 75+% of my Alpha ($5k).


On the forum there is a lot of FUD created around the Computer as a source (SSD's, Process Switching, NAS specs, Cable specs, computer type, player choice) - as I point out if your DAC of choice has the correct samples at the correct time then the source of bits is irrelevant. (mainly because Latency is irrelevant in the playback system - much more of a problem is cell phone calls, transatlantic calls, satellite systems etc..)


Yes clocking (distribution) is only a problem is a sync system - the future should be in the async delivery of the data to the conversion device - this way we can have proper flow control and better isolation (less time dependence) from the source. In communications and supercomputing (my business) we moved wholesale from time based systems (TDM) to ATM (Async Systems). My team hold many patents in this area.


In selecting the DACs people should seriously consider the firewire DACs. I chose the Alpha DAC and chose to solve the clock distribution problem it created.




Serious Listening:[br]Intel Mac Pro 6G (SSD) -> Amarra ->Alpha USB ->Alpha I Dac -> Ayre KX-R -> Tom Evans Linear Class A -> Avantgarde Mezzo Horns (107db) + Basshorns-> Engineered Room (Power, Traps, Helmholtz Resonators, Ceiling Diffusers)[br]Computer Listening:Intel Mac Pro 6G -> Lavry DA10 -> Adams S3A Active Monitors

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Hi Paul,


The better the feed the better the performance of the DAC should become a wide-known fact now. I was so surprised in the sonics I heard from my OMZ DAC/PREAMP fed by the Lynx AES16e card in my PC.


> Subjectively my Benchmark plus Reclocker (total approx $2k) is 75+% of my Alpha ($5k).


I wonder how much performance gain (subjectively) in your Alpha from the Reclocker alone ?




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Thanks Paul

you are of course 120% correct in all you say. I misinterpreted your post. My apologies. What I thought you were saying was - "forget an Alpha, just buy a benchmark and reclocker." - what you were saying is, I think, is this is a great device for improving mid range sync dacs.




Best Wishes


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Let me preface this by saying that my Amarra experince is not the consensus on CA:


The reclocker (so far) has been the biggest single improvement that I've made to my main listening system. It widened the sound stage dramatically and focused the instruments - my wife could not believe the difference.


Having said that I have 2 systems outlined below. In my main system there is no discernible difference between itunes playback and Amarra playback - I choose to use Amarra as it handles the various rates. I am in the minority here.


Last weekend I tried Amarra on my 'office' system for fun. Boy what a difference it made! - it removed the harshness of the music.


So I set about comparing my two systems. The conclusion I have come to is that my media room system MAC pro is very 'clean'. No excessive processes executing - mimimal background tasks - no monitors - no multiuser accounts no drive fragmentation- whereas my office system routinely has 100+ processes running.


I dived into the kernel and found playing the same song on two systems (identical macpros - identical processors - same processor batch even, and identical memory - identical OS's) that itunes had 40 threads on my office system and 21 on my media room i.e. under the covers they are doing different things. I conclude that itunes works ok if nothing gets in its way - other scheduled processes whereas Amarra works properly - meaning better kernel priority's.


So far my experience is that hypothetically given only $1k (by the wife) to spend I would reclock (for signal integrity, isolation and giving me a longer cable length to the computer) and keep a very clean computer system. Of course I would then not hesitate to make a new 'case' for Amarra.




Serious Listening:[br]Intel Mac Pro 6G (SSD) -> Amarra ->Alpha USB ->Alpha I Dac -> Ayre KX-R -> Tom Evans Linear Class A -> Avantgarde Mezzo Horns (107db) + Basshorns-> Engineered Room (Power, Traps, Helmholtz Resonators, Ceiling Diffusers)[br]Computer Listening:Intel Mac Pro 6G -> Lavry DA10 -> Adams S3A Active Monitors

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Np - you nailed it - I loved my Benchmark (2007) - then I loved my Lavry (2008) now I love my Alpha ;)


As an aside - the reclocker cost less than my Audiophile cable (purchased some years ago now when I was younger and more foolish).




Serious Listening:[br]Intel Mac Pro 6G (SSD) -> Amarra ->Alpha USB ->Alpha I Dac -> Ayre KX-R -> Tom Evans Linear Class A -> Avantgarde Mezzo Horns (107db) + Basshorns-> Engineered Room (Power, Traps, Helmholtz Resonators, Ceiling Diffusers)[br]Computer Listening:Intel Mac Pro 6G -> Lavry DA10 -> Adams S3A Active Monitors

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To answer directly:


An async system is a much better delivery system than sync. Having said that the mechanism of data transfer can matter e.g. USB (shared) is not as good as Firewire (essentially channelised) - there is a QoS spec, flow control issues to deal with. I have several patents in this area.


However... for the audiophiles the DAC process matters i.e. filters, sampling etc... Arguably the Audiophile DACs are still very sync based - the 'lesser' Studio Type DACs e.g. RME have async ports. I think this is changing or has changed - I've not (yet) experimented with Wiess, Sonic etc.. but technically I think they have a significant physics advantage - reading clay's posts I think he has great insight into this area.


Some Audiophile DACs have a clock input - I tried to convince my wife to allow me to get the Atomic clock from Antelope into an OCX into the Alpha (but the Alpha doesn't have a clock input....) There is a thread on CA which talks about Alpha's decision not to add a clock to their DAC.




Serious Listening:[br]Intel Mac Pro 6G (SSD) -> Amarra ->Alpha USB ->Alpha I Dac -> Ayre KX-R -> Tom Evans Linear Class A -> Avantgarde Mezzo Horns (107db) + Basshorns-> Engineered Room (Power, Traps, Helmholtz Resonators, Ceiling Diffusers)[br]Computer Listening:Intel Mac Pro 6G -> Lavry DA10 -> Adams S3A Active Monitors

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Thanks for your insight, Paul !


Some months ago, I had been thinking to get a decent CD transport after borrowing a $$$$ unit from a friend of mine. The Lynx AES16e changed my mind looking at the PC transport path. Thanks Chris for the great collection of knowledge here !


However, the Lynx still doesn't offer the "best" sonics I wish to hear in my system, compared to a modded transport I've auditioned. The question would be whether it's a fault of the digital transmission or the DAC. Consequently, which improvement path to take ? Is this about the jitter "thing" ?


Your personal observation indicates the benefit of "transmission" reclocking. There are a bunch of such devices, but I personally think the USB reclocker would be the most convenient for typical PC audio setups. I wish a quality USB reclocker should be priced below $300. ;-)


Some friends of mine believe synchronous reclocking is the only answer for the best sonics. Perhaps, USB async DACs would be the final winners. ;-)


A DAC I own has a decent (very transparent) analog output stage which has a significant impact on the sonics as well. Bob's BADA has such custom discrete output stage and a custom clock.




I don't mean you should do a mod, but the next bottleneck could be in the analog section. Should you proove this to your wife. ;-)


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Recommended master clocks?


Okay, presently I have a G5 with a Lynx card feeding the Bryston DAC via a custom Redco AES/EBU cable. I am a newbie but I was considering purchasing Amarra. I haven't read too much about reclocking with a master clock. I don't understand it and I don't want to. (So there!). I DO understand music and so I should probably consider/thinkabout/mullover/drool on myself/ etc. the possibility of adding a master clock. Do I have any options other than spending $1200 on the Anteloupe. Is is by consensus the best master clock. Tell me how all this get cables together. I feel that's sort of a dumb question but in other words, with the master clock in the chain, you have the same AES/EBU cable feeding the clock and then you're passing the digital signal again from the clock to the DAC (and over what type of interface? AES/EBU)? Advice? Suggestions? Ideas?


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I think the most common suggestion would be to not use an external clock to clock per se, but to reclock the digital signal. The Antelope Isochrone DA in this application takes the digital signal from the Lynx and then reclocks the output to have less jitter. The Lynx doesn't necessarily take any signal from the Isochrone. This is similar to the Apogee Big Ben which is a master clock, but also has the function of reclocking digital signals, or the Genesis Lens or Empirical Pacecar which just reclock a signal. So, yes you have many options other than the Antelope, but I don't know of any comparative reviews upon which to base a decision.


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Thanks. On top of that I imagine there is also significant opinion out there that the output of the Lynx card is already low in jitter - quite perhaps low enough not to require reclocking? And then again you have the processing going on inside the dac to remove jitter (such as the Bryston).


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Hi Chris,


The Isochrone OCX's specs look very impressive.

The Black Lion's Micro Clock looks very interesting, but it comes with only 3 BNC outputs. Removing an "esoteric" front panel would cut the price by half ?




Perhaps, you may give it a try too.


BTW, the amount of the jitter tolerance inside the DAC, such as the S/PDIF receiver's, could be higher than of the reclocker though. ;-)





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I own the Black Lion Microclock MK2. It's the best clock out there for the money in my opinion. I prefer it over the Apogee Big Ben but that's in my setup. Matt Newport, the founder of Black Lion Audio, is an extremely helpful guy and truly cares about his customers. For instance when I bought my Microclock last December they forgot to include my standard $25.00 BNC cable in my package; after shooting them an e-mail they shipped me their $50.00 premium BNC cable at no extra cost 3 days later. Talk about customer service. I wonder if they could offer a trial for the Microclock? For $475 it's not a bad deal.


david is hear[br]http://www.tuniverse.tv

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For fun:


To test the reclocking I swapped out the MacPro(SSD)/Lynx for an (direct connect) Ethernet connected Sonos box. The music server is in my office (another room on the network).


I fixed the output (meaning that the sonos box did not sample alteration) then fed the output into the reclocker.


I played HDCD music - nice blue light on the Alpha DAC (some believe that this means the samples are reaching the DAC without any alteration).


Jitter should be controlled with the DA.


This is essentially an async like system with Ethernet replacing USB/firewire.


It performs at 90%+ of a my computer fed system below. My surprise is that it doesn't perform at 100% of the system below - However for people who don't want to go the whole 'computer' in the media room root - this is very very good.


A downside is that you can only play 16bit/44.1 sound (other files get adapted down).


The sonos can be controlled by ipod/iphone. The player avoids the use of itunes.


There may be other Ethernet/spdif solutions I have not tested these - I have tested the Sonos.




Serious Listening:[br]Intel Mac Pro 6G (SSD) -> Amarra ->Alpha USB ->Alpha I Dac -> Ayre KX-R -> Tom Evans Linear Class A -> Avantgarde Mezzo Horns (107db) + Basshorns-> Engineered Room (Power, Traps, Helmholtz Resonators, Ceiling Diffusers)[br]Computer Listening:Intel Mac Pro 6G -> Lavry DA10 -> Adams S3A Active Monitors

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  • 2 weeks later...
  • 4 weeks later...

Their is another choice out there for hi end clocking and re-clocking, Grimm Audio.




I have not had a personal opportunity to use one, but am familiar with their work in general and regard it well. Their white papers are worth reading as well.


perhaps if I post here someone will try it out and report back!!


they come from the production side of the business (like myself) and are interested in raising the production quality of recorded media.




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  • 1 month later...

Based on the favorable review by Paul (aka Happy) of the Isochrone DA I ordered one to try in my Zalman PC/Lynx AES16 > Berkeley Alpha DAC (BADAC) system.


It arrived yesterday and the improvement it made in sound quality was immediate and quite significant. The DA significantly reduces what I would describe as a "blurring or smearing" of the entire audio spectrum by: (1) electrically isolating the PC/Lynx from the BADAC (thereby reducing noise) and (2) reclocking the data thereby reducing jitter. Every aspect of sound quality is improved - it is not subtle and once you hear the improvement there is no going back. I wonder if performance could be further improved with the Antelope Atomic clock....but I'm not sure if the bang/buck makes sense.


Overall, I would echo 100% of Paul's comments and am very appreciative of his post on this device that I otherwise might never have auditioned. Personally, I'm surprised/disappointed that this type of device would be needed after plunking down $5K for the BADAC. in other words, why couldn't a reclocking function with the performance of the DA have been included in the BADAC?


As an aside, I see that Antelope is coming out with their own Zodiac line of DAC's which has an impressive feature set - AES/SPDIF/USB async inputs, reclocking with thru outs, atomic word clock input, DC power, analog volume control with XLR output, etc. Since the Zodiac offers the reclocking/thru outs of the DA I may return my DA and get one to A/B versus the BADAC - it could be pretty interesting as the top of the line Zodiac will go for $3500 as I understand it.


I know the guys at Berkeley are not standing still and one has to respect their design prowess. Supposedly they will be coming out with a box that accepts USB async input and does electrical isolation in early 2010.


Bottom line, I would recommend anyone with an AES/SPDIF DAC to try a reclocker if you are interested in getting the maximum sound quality out of your system. I would also say that any comparison of the BADAC to an asynch firewire/USB DAC such as the ULN-8/Model 4 and others, without the use of a reclocker is likely handicapping the BADAC. I would quickly, however, agree that when you add in the cost of a Lynx card ($700) and reclocker ($1000) to the cost of the BADAC ($5000) versus a firewire/USB DAC the latter may be more compelling from a price/performance standpoint. That being said, one would need to A/B them to make a final determination.


As someone else noted, I can't say if one reclocker would be better than another. I do know that Antelope enjoys a solid reputation in the pro community and with the Berkeley engineers who recommended their predecessor company's (Aardvark) gear for use with their Model Two DAC/ADC.






Mac Mini / Pure Music > Firewire & USB > Metric Halo LIO-8 > Hypex NCORE 400 > Geddes Abbey Speakers > Rythmik Servo & Geddes Band Pass Subs // DH Labs Cables, HRS MXR Isolation Rack, PurePower 2000, Elgar 6006B

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I see that the DA is a "distribution" system -- but is it it's own clock, or do you need an external one?


I'm interested in the "re-clocking feature", specifically, fwiw. I take it that this is the only product in this vendor's lineup that offers that feature?


Also, does anyone know if the Zodiac is going to offer re-clocking on it's inputs?


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