I can't tell the difference


I have a primate I21 integrated amp, bowers and wilkins cm5 speakers, and a slim devices squeezebox. I recently purchased a musialcal fidelity v-dac thinking the squeezebox's dac might be my weak spot. I've done a blind comparison between the sb3's dac and the v-dac but I can't tell the difference between the two.

I really thought that the v-dac should have been a significant upgrade seeing as how it costs the same as the sb3 which has a lesser burr-brown chip and a ton of other componets where with the v-dac you are just paying for the dac and nothing else.

Should I be able to hear the difference here? How much do I need to spend to upgrade my source?
mustard
@Richard_stacy -- I agree our ears are the end-all-be-all. However, the laws of physics cannot be evaded. There has to be some logic to where we look for differences, no?

Have you done any blind tests with your digital interconnects? I'm very open to the possibility that I'm wrong here, but I'm one of those people that needs to understand why something works... maybe I'm in the wrong hobby :)
you know, i do understand that but i have just come across so many weird things after messing around with this stuff for years. i'm sure there are reasons for why digital cables sound different i am just not able to understand yet alone explain the bulk of it. no, i have not done blind tests but i have a very revealing system and can assure you these differences are not subtle. my digital cable is hands down one of the biggest contributors to the level my system is operating at these days. if you only knew how my power conditioner worked...you would really think i was nuts!
could you point me to some documentation that describes how a cable could impact the spdif transmission?
You'll find this article to be of interest. It explains how cable LENGTH can be significant for spdif transmission, by affecting jitter:

http://www.positive-feedback.com/Issue14/spdif.htm

Of course the degree of significance of the effect he describes will be dependent on many variables, that will be different from system to system. Those include the jitter rejection capabilities of the dac, if any; the risetime and falltime of the transport output signal; the degree of impedance mismatch between cable, connector, transport output circuit, and dac input circuit; the exact logic threshold of the receiver device in the dac input circuit; the data rate that is being transmitted; the amount of electrical noise that is present, etc. etc.

For a given cable length, different cable types will affect the degree to which some of those variables come into play, particularly impedance matching and noise pickup, both of which will in turn affect jitter.

Regards,
-- Al
Mustard, let me unload a well known message here: break in, break in. How much time did you grant the V-dac before critical listening? I know it's hard to grasp how long fine dacs (no moving parts, only kind of electronic alchemy) need to come to themselves.
I did't hear the V-dac and have not read owner's reports concerning its break in characteristics, but, given how unresolving and unengaging the SB3 dac sounds, I would be surprised if a well burned in V-dac didn't lastly lift sonics quite a bit here.
When new, even seemingly simple units like the Valab dac need a week of constant converting work, after which it likely outperforms Lavry DA10 or the Transporter dac, as my ears were inclined to tell me.. As does, to a still higher degree, the new Wadia 151 in my system - and similarly, only after a week of having run continuously.
Well, all this burn-in talk might be old hat to you! Sorry in that case. I just wonder how many machines are being judged, sent back or reported on ahead of due time.