Article: Computer Audiophile Pocket Server C.A.P.S. v3 Carbon

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Is the PW-12V5A-L5 enough of a power supply? I note that the Bryston BDP-2 has a bumped up linear PSU with "over 5 amps, 10 amps peak". With an internal SSD and a couple of connected USB drives, how much power do you think is drawn?

 

Why don't you just ask Bryston?

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I agree. Bravo.

 

And to top it off, finding companies to assemble it for you if you are not so inclined!

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Thanks Chris. Funnily enough a friend of mine and I had been working on a similar setup, having explored the Bryston product, before stumbling on your write-up and the replies above. We, though, are interested in feeding an external DAC (such as the Theta Casablanca) over AES/EBU or S/PDIF (and hence the interest in the Bryston with its Juli@ card which allows one to toss the potentially polluting analogue section/DAC). Coincidentally, we had decided on the same Streacom case that was linked to above. The motherboard, sound card, enclosure and software side (assuming paying up for Windows and JRiver) is relatively easy; a good linear power design is the hard part and, in my view, utterly critical. Hence the question regarding power requirements. I'm interested in determining a max load with plenty of headroom for a system running a connected SSD and a few attached USB drives.

 

I am sorry if my statement seemed dismissive or rude before. In part my comment was associated with the extra power required by the card and drives you mentioned. Furthermore, if one is to keep attaching items to the same battery pack, they will in essence be corrupting that battery supply as well as one would with any other by modulating the load with the different items. I imagine one can add SOtM sata filters, but I am not convinced taht something like that is completely immune/perfectly filtered. That also does not take into account that the total load should not reach maximum with any power supply as that just begs for additional ripple and other impedence related issues. I imagine it would be best if one were to have a separate power supply per load, but that would get darn expensive.

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JJJ: Overkill? Maybe...

 

In analog, power supplies are directly related to sonics, and there is no such thing as going too far. The better (best?) gear will have separate power supplies for each gain stage and possibly for each channel there of. The more involved with digital I become, the more I see it similar to analog in many aspects. I feel that bits are bits for the most part, but along with them rides the power supply noise(s) that for some reason impart a signature upon the latter conversion.

 

I am not sure of the actual cause, but it may be something as likened to a moving coil gain stage where the PS noise is equal to and added into that stage's output only to be further amplified. Jitter seems to be the single biggest issue in conversions. Clocks play an important role in that, and they are very sensitive to power supplies and proximity. Put most simply, I no longer take anything digital for granted. It is digital, but still subject to the laws of physics.

 

Many software/IT professionals seem to take bits and check sums for granted, and it often leads into these circular arguments based on assumptions and disbelief. Considering the net cost of my system, spending extra money to assure more isolation seems money well spent. My next server will incorporate this type of thinking...

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Don't get me wrong. You and I are coming at this from the same perspective. What I meant by potential overkill was having each rail completely isolated a la Paul Hynes's unit. I'm probably going to try to adapt a linear power supply Jaehong Lee offers for the Oppo 93/103 player. It supplies 5V, 5V and +/-15V (the first 2 powering the Oppo's digital stages while the second powers the analogue board). I have to believe this can be readily adapted to drive a USB board, SSD and main motherboard, respectively.

 

Makes sense to me!

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wappinghigh: I'd recommend liFePO4 batteries instead- better impedance and rechargable.