Antelope Isochrone OCX - mini review

[ShinOBIWAN]

Had my Isochrone for a few days now and thought I'd post a few thoughts about quality and improvements its made to the system as a whole.

The Isochrone is connected to an RME soundcard via BNC wordclock, with the RME set to slave.

I'm using the RME clock as a base for my comparison, just for those interested, jitter on the RME is rated at <800PPM and the Isochrone is <1PPM. Quite an improvement on paper.

The only thing I can really say about this clock is that it works and in a quite spectacular fashion, gone is any digital type harshness to the sound, detail is really first class and imaging is sharper.

I was quite weary about being sucked in by something as esoteric as a master clock but the improvement its made is right up their with the biggest changes you can make, especially when you move up from a 800PPM clock 😉

I'm now looking forward to moving to external DAC's as funds allow.

Any others out there who use the Isochrone and what are your thoughts on its performance?

 

[wytco0]

ShinOBIWAN, interesting I dont know this device, how does this fit into your system? whats the advantage of it?

 

[ShinOBIWAN]

Hi,

Its actually a master clock to which all other bits and bob digital use as a reference for time when generating audio signals.

Full details on the Isochrone are here:

http://www.antelopeaudio.com/products_iso_ocx.html

 

[stolbovoy]

I'm using the RME clock as a base for my comparison, just for those interested, jitter on the RME is rated at []<800PPM and the Isochrone is <1PPM. Quite an improvement on paper.

It is not jitter. It is frequency inaccuracy, which by itself IMHO do nothing with sound quality.

 

[oehlrich]

The Isochrone is connected to an RME soundcard via BNC wordclock, with the RME set to slave.

Hi,
I currently build a PC as you described with FIR XO on a linux-base using BruteFir. First let me say you did a great job!

Now to my question:
As far as I understood you use the analog outputs of the RME HDSP9632 as I did and synchronize the RME-Card to your external Clock by Wordclock. As far as I understood inside the 9632 a PLL runs restoring the Masterclock for the A/Ds from Wordclock. This means jitter is produced system imanently by this PLL no matter what is input! So you could connect a wordlock with ZERO Jitter but would get pll created jitter at the analog outputs.

I am currently working on a solution with the Tentlab modules which creates NO PLL jitter inside the 9632.

What would really help me with my research if you would have a chance to tell me (by measurenet) what signals you find on the 10 pin connector to the WCM if it is operational with external sync.

Thank's a lot
Charly

 

[ShinOBIWAN]

Re: Re: Antelope Isochrone OCX - mini review

Hi,
I currently build a PC as you described with FIR XO on a linux-base using BruteFir. First let me say you did a great job!

Now to my question:
As far as I understood you use the analog outputs of the RME HDSP9632 as I did and synchronize the RME-Card to your external Clock by Wordclock. As far as I understood inside the 9632 a PLL runs restoring the Masterclock for the A/Ds from Wordclock. This means jitter is produced system imanently by this PLL no matter what is input! So you could connect a wordlock with ZERO Jitter but would get pll created jitter at the analog outputs.

I am currently working on a solution with the Tentlab modules which creates NO PLL jitter inside the 9632.

What would really help me with my research if you would have a chance to tell me (by measurenet) what signals you find on the 10 pin connector to the WCM if it is operational with external sync.

Thank's a lot
Charly

Hi Charly,

Thanks for the kind words and I'm happy there's another person enjoying the PC as a stunning platform for a highend source and filtering solution.

All of what you write about the RME is valid. Its limited because it uses standard wordclock which incurs PLL conversions. I'm glad to say I've moved on a little bit since I originally posted the 'how to' for the PCXO and this very thread.

Right now I'm using a Lynx TWO B soundcard connected to an Apogee DA16X. The Apogee has the BigBen master clock integrated into it as well as 16 x192Khz/24bit DAC's so its very flexible and sounds great. Aside from this I have the masterclock in the Apogee now connected to the Lynx via wordclock 256X or superclock as its sometimes known. The advantage is of course no PLL conversions 🙂

Sorry but I can't help you with the HDSP 9632 as I never looked into it that deeply. Speak to Vil who has done a similar mod on his Audiotrak Prodigy card.