Antelope Isochrone + ULN8/Model 4

[bdiament]

I could be wrong of course but upsampling everything to 192k would surprise me in this design.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

[cfmsp]

Chris,

Thanks for the quick response.

 

File attachment capability is not what I was thinking of. I was imagining a place (think of Apple's software list) where scripts, templates - perhaps even beta releases of software could be placed by vendors - can be viewed by forum members WITHOUT having to know in advance that such a script exists.

 

Examples include, your very own RAM Disk script, the Amarra provided re-nicing scripts, other various scripts, Metric Halo setup templates, etc. Perhaps even links to the beta software for say - XLD, Pure Vinyl/Pure Music, Amarra, etc.?

 

just thinking out loud here,

Clay

 

 

 

[cfmsp]

 

Understood.

 

and just to be clear myself - I'm only stepping down from the choir. I will continue to look for a DAC that offers top notch sound quality without use of an external clock - which I think will provide the best sound for value - irrespective of whether that DAC can be improved with an external clock.

 

Said another way, I'll eliminate prejudicial thoughts as to the quality of DACs based on whether they can be improved by external devices (anywhere in the chain).

 

clay

 

[earflappin]

I am not 100% about how exactly the BADAC upsamples. My presumption is based on the following posts and an interchange with OriTek who did the clock mod for Untangle on his BADAC.

 

This is post from another thread regarding the BADAC clocking.

 

"An interesting aside is that Bob W. ("untangle") found that the BADA uses a 25.5760 MHz clock regardless of audio sample rate. This implies that the BADA DAC uses asynchronous sample rate conversion to convert all sample rates to 192 KHz.

 

This would eliminate the possibility of synchronizing the clock of the S/PDIF converter or sound card to the BADA clock when playing 44.1, 88.2 or 176.4 sample rates."

 

The following is from their website:

 

"Unequalled interpolation technology up-samples 44.1kHz CD’s to provide almost 176.4kHz quality and produces superb fidelity at all sampling rates from 32kHz to 192kHz"

 

[aljordan]

It makes sense to me that an external clock would improve the performance of the Lynx card. Wouldn't the Lynx card have to derive its internal clock from the computer's PCI clock? I would imagine a custom external clock would be more stable than the computer's PCI clock.

 

A few months back I tried various ways of feeding my Prism Orpheus as follows:

 

1) Firewire with the Prism Orpheus set to master clock (which slaves the computer to it).

 

2) AES / EBU via my Lynx card with the Orpheus acting as the master clock and slaving the Lynx to the Orpheus via the Orpheus' word clock output.

 

3) AES / EBU via my Lynx card with the Lynx card acting as the master clock.

 

4) Firewire with the computer acting as the master clock

 

Configuration 1 and 2 outperformed configuration 3 and 4. I thought configuration number 1 offered the best combination of resolution and smoothness. However, when the the Orpheus was being fed by the Lynx via AES / EBU, I was surprised by the increase in resolution when the Lynx was slaved to the Orpheus' word clock as compared to when the Lynx was using its own clock. I suppose I shouldn't have been surprised as Prism is known for very good clocks. I've never tried slaving the Orpheus to a high quality external clock though.

 

Alan

 

[earflappin]

Hi Alan, I hope you continue to enjoy your Orpheus. Thanks for sharing your experience.

 

I'm not surprised the firewire was the optimal interface given the Orpheus' design, but it's cool that you ran the tests. Mani, who posts on CA, and has a PM Model 2 has also found that slaving his RME AES card to the Model 2 master clock significantly improves resolution. I think these findings serve to further reinforce the theory forward by many that using an async interface driven by the DAC master clock is the optimal approach....provided that the holistic system is properly designed and executed.

 

According to the Lynx manual, they have their own on-board oscillator to derive the sample clock, but clearly the board draws its power from the PCI bus and operates in a fairly hostile EMI/RFI environment.

 

Chris' recent article on the superiority of the Mykerinos AES PCI board and software, as well as others who have found that the Model 2 outputs an AES signal superior to the Lynx both confirm my findings - the Lynx produces levels of jitter and noise that are audible when feeding a Berkeley (perhaps other DAC's as well).

 

Why Berkeley did not design their DAC with a word clock output and galvanic noise isolation on the inputs is a question I would love to hear them answer. Clearly they must have known from their Model 2 experience that slaving the source to the DAC master clock is a superior solution.

 

Unlike most other DAC suppliers, Berkeley keeps a very low profile in terms of communicating with their customers. I don't believe I have ever had an e-mail returned from them. Michael Ritter is, however, good about answering questions on the phone. I suspect the majority of their customers are sufficiently happy with the BADAC performance that they aren't raising the kind of issues I'm raising.

 

I'm going to audition a ULN-8 and the new Zodiac Plus before I invest more time and money in optimizing a legacy and technically inferior interface like AES.

 

[aljordan]

I thought this review of the Grimm CC1 clock was an interesting read. It talks about some of the advantages and drawbacks of using an external clock.

 

http://www.grimmaudio.com/product_info/TapeOp%20CC1%20review%202010.pdf

 

Alan

 

[Clybourne]

Some interesting posts here. I can understand what Silverlight is saying when he says he likes the clocking on most, but not all material. Sometimes distortion (which is what jitter manifests itself as) sounds better. I should further note, that I'm talking about what our inventor would call "bad jitter". "good jitter" on the other hand, is what's created in our jitter management module. What Igor Levin has done is use some finely tuned jitter, much the way dithering is used, to improve the performance of digital circuits.

 

 

 

 

 

 

 

As far as "mucking" with things. It actually isn't. I was present for tests done on a John Coltrane master tape and the converters which created the most accurate replication of the originals, were clocked with Trinity and 10M. It so convinced the guys at Universal, that they now put stickers on all their masters stating "atomically clocked by Antelope".

 

Zodiac Plus is shipping very soon and I already have the first few final units. Here's a demo I did yesterday in Amsterdam.

 

 

 

 

 

 

 

Let me know any other questions I can help with.

 

Regards,

 

Marcel

 

[cfmsp]

 

Marcel says:

 

"good jitter" on the other hand, is what's created in our jitter management module. What Igor Levin has done is use some finely tuned jitter, much the way dithering is used, to improve the performance of digital circuits."

 

Now that is my candidate for the most interesting comment of the month.

 

Marcel, can you share more about this?

 

Very curious,

Clay

 

[labjr]

Marcel, Are you making this up?

 

This sounds like something Nigel Tufnel might say.

 

Regards,

 

Larry

 

[cfmsp]

 

Bob Stern uncovered a video that speaks to this. It's posted on AA - PC Audio forum.

 

clay

 

 

[ted_b]

and draws the analogy of using dither noise to negate bad noise. Interesting stuff. Not for the flat earth folks, though. But you guys know better...this computer audio stuff is clearly an area where we know wayyyy less than what we don't know.

 

Here's the link again (it was in Marcel's original post).

 

[dallasjustice]

I output from my computer via Lynx AES 16 via AES to an Isochrone DA and then to my NAD M2 (DAC+amp combo). The NAD M2 does not have a W/C input. The addition of the Isochrone DA made an excellent improvement in sound. After having read some of these posts, I decided to get an external master clock. I ordered the Antelope OCX from Sweetwater. My question has to do with how best to hook it up in my system. Robert at Sweetwater recommended a BNC connection from the OCX to the DA. He said it would be unnecessary to also connect the OCX directly to the Lynx AES16. Do you have any advice on how best to connect the OCX external clock?