Build a dedicated Audio PC

[jkeny]

A question that was posed to me in Nige's about running batteries at lower than optimal voltage has made me think a bit about the whole battery shunt thing..
I had some pause when asked & what was at the back of my mind but I didn't articulate it correctly at the time was that the effectiveness of the battery to act as a large capacitor & absorb PS noise may be less effective at lower voltages than the battery is rated to operate at. This probably depends on a number of factors:
- how far below rated voltage the battery is being run i.e. running a 12V battery at 5V may be worse than running a 6V battery at 5v
- the battery chemistry. i.e LiFePO4 batteries would be just on the edge of depletion at 2.5V each (2 batteries in series to give 5V)

[tony]

Anybody drop something on the way back from Nigel's?
http://www.irishtimes.com/news/crime-an ... -1.1497751

Ahh yes....that might explain all those pot holes then :-))

Only one Caucasian has the accent required for that type of stuff now I know why he was driving so carefully around the potholes.

Pearse have core server on usb stick on audiopc. Reboot issue is problem with evaluation copy. Had another issue with SSD loaded server using my medion desktop.Turns out it is an amd chip. The SSD is visible but will not boot on the audiopc. Will need to reinstall using the audiopc.

[Sligolad]

Strange that Tony as all my server core installations on SSD's and USB sticks have been using the evaluation copy.
Not sure if it makes any difference but I always install core server direct, I have never run an install with GUI.
Not sure if this makes a difference but I have not hadf any stoppages so far.

[tony]

Sure I always get the strange ones wonder why! I though it was more than likely some bios setting but audiophil suggested early end of evaluation copy. BTW just to see how many updates are available I went online with this copy.

[nige2000]

2 pcs streaming with the two of them powered from the same three batteries and three linears

guess what that sounds like?

We were listening to only one PC off batteries when we visited?
So I guess this is better sounding - how much better?

hard to explain how much better, it all has a similar effect only theres more of it (improved dynamics, more immersive and more clarity)

the control pc i used that day isnt great for music (well at this level anyway) it was powered via one linear and its power hungry

i got the sense that streaming to a tri-battery system from a linear setup was like taking two steps forward and then one back by using a slightly dirtier supply
(i realise the irony of that statement)

i definitely didn't need a-b testing, 30 seconds into a track was sufficient proof for me
best guess that is its a similar improvement again from tri-linear

trouble is with the batteries normally charge up to well above there rating
eg vehcile batteries to almost 14v


i think on two lifepo4 would need to use a voltage divider and charge them to 3.2v each and then charging is a problem as cant charge them in series, then it gets complicated

nige

[jkeny]

Yes, Nige, we were able to tell the difference in the first 30 secs when we were with you that night.
So I guess there is a similar upgrade in body, dynamics & richness working with all batteries.

[nige2000]

Yes, Nige, we were able to tell the difference in the first 30 secs when we were with you that night.
So I guess there is a similar upgrade in body, dynamics & richness working with all batteries.

oddly enough on a two pc system running each pc on their own single battery (no linears except 1 to charge the battery) had a severe lack of body but great detail

it takes three to get it back

it seems that separating the power supplies has brought great results and the same seems true with the batteries as well
John mentioned to me that we may be bypassing some grounding issue that is likely to be difficult to fix

As i have caused some extra clutter in a few guys rooms by suggesting extra linears,
ill try to redeem myself

i managed to fit he 5v linear into the case for a more compact straight forward linear solution



this is one of my favourite modifications

[jkeny]

I thought this might be of interest to PC builders here - it seems the new Haswell chip achieves it's power savings by incorporating the voltage regulators on the CPU die itself http://www.extremetech.com/computing/15 ... enthusiast

The external supply of 1.8V is split into the various voltages needed by the CPU within the CPU itself. This might be a good or a bad thing for us audio PC builders, who knows? On the one hand far easier to supply just one supply (1.8V) of quality to the chip - pity it isn't 3.3V though? On the other hand we have no control over the quality of the on-board voltage regulators - I imagine they will be fine & not generating spurious noise :)

On another front Windows 8 has been banned from the major benchmarking site, HWBot because it's Real-Time Clock is wrong "due to a fault in Windows 8′s real-time clock (RTC), which all benchmarking tools use as a baseline." So, guys, we are hearing the music at the wrong speed & didn't even notice it - those objectivists are right :)
http://www.extremetech.com/computing/16 ... cking-site

[tony]

Like any good luddite we will ignore any information damaging to the cause. It is blatantly incorrect,mistake,can't be show the evidence etc etc

[tony]

Further conclusive evidence from the experts how useless this battery testing really is. Note no mention of double blind testing.
Note I don't like providing ammo for JK's dislike of my supertweeters but sure what the hell.

" Dreadful mains shouldn't matter with a properly designed PSU inside the equipment. Most normal audio kit contains such a PSU though some audiophile grade kit doesn't.

Batteries can help with grounding issues but there are no other benefits over good quality regulated DC from a mains supply. There are some negatives from batteries, such as noise from the chemical reactions and higher source impedance.

So a complete waste of time in 99% of situations in which hi-fi is likely to be used."
__________________
Rob

www.audiosmile.co.uk