All very interesting.
I will see if i cand find a vista SP1 RC for you to download.

Aaah, I was assuming since on their website they say "bus powered" it was ONLY bus powered.

I have to wait and find a good deal on it, I do not feel playing full price

I think I have realized the main cause of difference in SQ between the FF400 and the FF800: the first is bus-powered and the latter is not.

My old xeon computer has pci-x slots, which require pin compatibility to use pci-32 boards.
But I think i'll go with the onboard firewire 400 and the FF400. In the worst case I need to upgrade the soundcard of this pc, because I use it mainly for music when I'm in the studio.

Uhm... and why did you get the FF 800 instead of the much cheaper FF400? Did you try both?
I thought one of the benefits of the ff800 was the wider bus.

I have this doubt, on my temporary music pc I have 2 onboard firewire 400 ports. I could get a pci (pci-x actually) Granite firewire 800 controller with TI chipset (i checked).

TBH I think I'll go with the FF400, and maybe use a master clock like the Big Ben.
*confused*

Peter,
Both connections were firewire 800?

I do think even a single 1543 is cr*ppy. I had a phone chat with an extremely expert friend that modifies cd players and he said that the dac section of the vrds 10 could not be modified due to the chip used and he didn't like it. Anyway, he thinks that the TwinDAC is good. How good both he and I will find out soon.

Peter, I was wondering if you ever did a test using a Lynx internal soundcard for digital signal transport to the DAC. Using as digital transport only the interference and noise may not pass through.

I just read this and I find also the Berkeley DAC very, VERY interesting. You should contact them and propose XXHE
http://stereophile.com/news/010508ref/

You will have them

At the moment I could not be happier even with the cr*ppy teac TDA1547 DAC, because after I changed speaker cables yesterday the difference is so huge that is like i changed the source or the amplifier.

I would like to stress this

Not considering firewire, USB to 12S woud be the second best. But a good reclock in the DAC (like  the one in the TwinDAC) can help minimize the jitter.

hehehe
I think it mounts the very same mechanic as my VRDS 10se, so it's a bit pointless
I'm eager to do this comparison. To make it more fair I got a XO3 clock for the poor teac.

Hmm, there must be also the cordless keyboard/mouse logitech set, but that's all. Anyway I'll test when i have all the equipment, so not so soon. But I will post my findings here.

My opinion (and it is supported by facts, which i'm too lazy and no tech enough to present) is this.
From less to more jitter (due to intrinsic limitations but also voltages, noise and whatsoever):

External Firewire dac
Extenal USB dac (USB to I2S)
External USB dac (USB to SPDIF)
Internal DAC (pci-e soundcard)
Internal DAC (pci soundcard)

Don't forget that firewire is used in professional audio and in modified version even in some high end audiophile gear.

Yeah, I also hoped to not have to optimize the hardware but only the software going pc route.

Just tried on my gaming machine (when i listen to music into headphones only, its a dualcore with vista x64).
Most spikes green, a couple of yellow along a 2 minutes test period.

This machine is NOT optimized for music, there are quite many background processes, including diskeeper, kaspersky7, outlook, uTorrent, msn and vmware virtual drivers.

I do experience an occasional dropout of music playback sometimes, thanks to creative cr*ppy drivers for the x-fi.

You have to wait about one month more for this.

The DAC will be in my hands around the mid of feb and the htpc when intel commands (even later i fear).
Besides, I havent decided to shell out more money for an external soundcard or not. I will start with the USB connection and compare with my modded Teac VRDS to see if the pc audio is up to it (it should be).

Hi Edward,

I dont have much to reply. About the ram, it could have been the voltage you used that was too low for the Corsair modules.
Even if rated higher, sometimes the voltage that a module requires to be completely stable is higher as well. It depends on the chips used. For overclockers some series of micron chips were the best last year. I think to remember that cics suggested to raise the ram voltage of 0.1v in one of his posts to improve SQ - that can actually improve the stability.

About USB, in short usb to spdif has intrinsic jitter. Good DACs like the TwinDAC reclock it to minimize the jitter, bad DACs like m-audio do that poorly and they are very susceptible to. Another good option is to use USB to I2S, which if well implemented it is superior to usb-to-spdif, no matter how good is the jitter correction in the DAC.
This is why Peter uses the Fireface 800 (and not only him) to transport the digital signal to the DAC. I have come to the conclusion that the improved SQ in this config is due to the lack of jitter from the USB bus.
I wonder if the cheap ESI Duafire (200€) would be good enough for just this task...

To sum up, you made me think more of power optimization for my HTPC that I dint want to consider (i.e. double psu).
You should really try a firewire DAC, though

Another relatively cheap nos DAC that has got a lot of praise is the Altmann. 750 euros.

About me, I have been lucky enough to find an used TwinDAC+ (Thanks Gerner ) )

Still debating if to use a fireface or an esi firewire as signal transport to the dac.