[leeperry]

Quote:

Originally Posted by thoppa /img/forum/go_quote.gif I got mine from a local shop. Same price.

BTW, real men bluetack their XO's: Valab Non-oversampling Dac (nos) Review - DTV Forum Australia - Australia's Leading Digital TV and AV Forum

it's 1ppm too: Valab NOS USB Re-Clock DAC Low Jitter Dual 1ppm TCXO - eBay (item 270446138194 end time Sep-21-09 12:02:44 PDT)

 

[ROBSCIX]

Quote:

Originally Posted by GWorlDofSPACE /img/forum/go_quote.gif You could also just bypass the opamps and use an external discrete I/V stage and a buffer stage! What do you think?

You mean build a passive I/V stage using discrete components and a active buffer?

 

[b0dhi]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif it's 1ppm too: Valab NOS USB Re-Clock DAC Low Jitter Dual 1ppm TCXO - eBay (item 270446138194 end time Sep-21-09 12:02:44 PDT)

They don't give any jitter specs at all.

 

[GWorlDofSPACE]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif You mean build a passive I/V stage using discrete components and a active buffer?

Yes, but just for try, why not this jisbos buffer instead of the last opamp!

Here the home page: JISBOS - overview

 

[ROBSCIX]

Cool. I have bee looking at a few schematics of circuits I want to try. I will have alook thx for the link.

 

[MikeW]

The DIR 9001 is supposed to be at 50PS jitter, the CM108 though has been measured, and did not fair well at all. Don't know the number just that they where bad.

Quote:

Originally Posted by b0dhi /img/forum/go_quote.gif They don't give any jitter specs at all.

 

[ROBSCIX]

The great thing about this mod on the ST is the further cleaning and stabalizing done by the Cirrus clock chip.

 

[riderforever]

Rob, do you think the CS2000 chip would still make any hearable difference on a clock with a rated jitter of <= 5ps like these?

 

[leeperry]

I think it'd have to be proven that the CS2k chip only improves things...and doesn't make them even more messy

 

[ROBSCIX]

Quote:

Originally Posted by riderforever /img/forum/go_quote.gif Rob, do you think the CS2000 chip would still make any hearable difference on a clock with a rated jitter of <= 5ps like these?

If it takes a generic clock and cleans it up. It should work rather well with a reasonably accurate clock.
If you want to know more about its function check out the spec sheet.
One way to know for sure, try it out!

 

[thoppa]

Hi,

If I understand the circuit, the CS2000 is cleaning the master clock from the AV100 (CMI8787/8788) ? That chip's datasheet says it has 750ps ! I sincerely hope it doesn't actually produce that much jitter. That's horrific. Anyway, I'd say the CS2000 is definitely still worth having even with a low jitter XO, because the XO is only one source of jitter in the system.

My ST sounds pretty sweet and detailed and is starting to exploit the ability of the HD650.

Tom

 

[ROBSCIX]

Thoppa, you said you heard a audible difference so it show that the clock helps with higher precision XO.
I have been thinking of doing a clock mod for ahiwle but haven't got aorund to it. Maybe I will soon.

 

[riderforever]

@192 khz you get 1 sample every 5208333 ps. A jitter of 750 ps means the error of the clock is below 0,02%, while a jitter of 5 ps takes it down to 0,0001%. I didn't think there could be any audible difference between these two values.

 

[thoppa]

Try it - I'm sure 99% of listeners will hear the improved details if nothing else. And probably a lot more ! The only way to go from skeptic to cognoscenti is to hear it !

 

[leeperry]

Quote:

Originally Posted by thoppa /img/forum/go_quote.gif That chip's datasheet says it has 750ps ! I sincerely hope it doesn't actually produce that much jitter.

nice find Tom! got a screenshot? what page of the datasheet?

well, yeah, this DSP chip sure sounds HELL messy to me...and the conditioner only adds even more mess on top of it *to my ears*...cheap consumer grade components at work

I was looking into the jitter specs of the Prodigy HD2 chip, but I can't find a datasheet for the VIA Envy24HT-S...I'll keep looking!

I also don't understand why it's got both a crystal(same as found on graphic cards) and also a XO:

one for 48Hz multiples, one for 44.1?

I know the Audiophile PCI has 2 crystals : http://www.m-audio.com/images/global...ophile2496.jpg

and the Audiophile USB(released 2 years earlier), only one: http://www.head-fi.org/forums/f46/m-...rested-208391/

...and it's supposed to resample everything to 96KHz(their techsupport says the opposite)...but some ppl say that you can get both 44.1 and 48 from ONE crystal