AUDIO PC: Direct power to motherboad 24 and 4pin (picoless)

[nige2000]

Memory power is a success.

cool

1.32 volts BELLESON reg fed by the 5 volts pack (now composed of four cells) to insure plenty of current, the higher voltage that is, instead of using the 3.3. Just gets warm after one and one-half hours. Must not need as much power as has been speculated but then this is a 2gB stick rated at 1.35 volts. Still I worried I might end up with a roasted regulator.

what type of reg is the belleson, i would have thought it would be more efficient using the 3.3v
there is an optimum voltage for all pc builds it just takes a little experimentation

More digital junk taken away, of course. No change in tonal balance but the mid bass has added attack - much more dynamic there. Starting to think there is nothing lacking there in the SOEKRIS - it is only reporting what it hears and if it is not there, oh, well ...

you begin to realise how bad pcs are for audio when a few mods are done
i had thought the soekris lacked in a dynamic response rate the dual mono pcm 1794 seems faster

Will post a picture of the rat's nest.

Discovered an easy way to find which end of the choke goes to the memory. Use a strip of copper foil - lay it against the pads on the back and with a multimeter you will quickly know which hole to use.

The reg w/heat sink sits to the side of the P24 header - helped having a cleaned up MB. Will remove the onboard memory power stuff next weekend.

Worst aspect of the nige2000 supply is soldering on the tabs - second is getting the batteries down to 5 (or 12) volts. That is what takes most of the time. Always takes more time than you wish when you do something like this for the first time. But the benefit: I did not wire it up backwards. If I had it would not have been the first time.

if you hook up the batteries to a reg set for 3.3, 2.5 or 3v connect up something like a car head lamp bulb and walk away it will leave the cells at the correct voltage

Finally placed a pair in the SSD power line, too.

I want to do the clock thing one of these days.

[rickmcinnis]

Never got around to getting a bulb. Did not realize it would make it that easy! DAMNIT. Used computer fans and paralleled resistors. Plus I was impatient.

The BELLESON is a HIGH drop out series reg based upon the Jung super regulator but simplified. I was worried there would not be enough current with using the 3.3 rail looking at the curves ... After all is said and done I probably could have used the 3.3 since the reg doesn't seem to be working very hard at all.

I asked MSI to send me a schematic of the MB I am using - have not heard from them yet. Sure would be nice.

I got some +/-5 volts and 3.3 regs for the SOEKRIS - these are fixed regs. I wonder will a fixed voltage reg work as a floater in this application? I know with the computer supply it is not as simple as setting the reg to the voltage you want but there is lots of current involved there.

With the SOEKRIS +- 5 volts supplies - with the 3.3 duties taken away - I do not think there will be any problem but I am wondering if i iwll get as lucky wit the 3.3. Do you have opinion?

Take care,

[jrling]

nige
you begin to realise how bad pcs are for audio when a few mods are done

Not many reading this thread would disagree with that, certainly including me.

I am sure it has been debated elsewhere, but considering that we are all just seeking a board that does the absolute dedicated minimum to play audio, is there not a 'simpler way' than using an unsuitable PC mobo?

I suppose what I am saying is a dedicated board for audio. On DIYAudio one reads of numerous projects where individuals design a purpose built board and get prototypes fabricated in the Far East for what seem like affordable amounts.

Of course, getting back to the subject of this thread, then one would not need all the complexity of a 24/4 pin ATX-type PSU with all sorts of DC-DC switchers on the board, because they would be designed out.

Actually, the ARM platform is getting closer to what I am suggesting; they are very low power (c.5W is typical) and seem quite happy to operate on say a 1.2v supply for CPU and only need 5v for USB.

Jonathan

[rickmcinnis]

A few pictures of the memory power regulator.

Tried the 1 meter SATA cable between the riser and the board - can't say I heard any difference but it probably doesn't hurt getting the USB card away from the board.

Need to come up with a better way to suspend the USB card.

Took so long to do the regulator install I did not get a chance to get out the heat gun. Will get rid of USB3 stuff this weekend.

Tried the 1 meter SATA on the SSD and it was not recognized - strange?

[rickmcinnis]

My 3.3 rail failed from overvoltage so I have ordered this to replace: https://www.batteryspace.com/lifepo4-pr ... d-dgr.aspx

Will not have to worry about power on that rail!

(Luckily I had a spare A123 on hand)

[nige2000]

My 3.3 rail failed from overvoltage so I have ordered this to replace: https://www.batteryspace.com/lifepo4-pr ... d-dgr.aspx

Will not have to worry about power on that rail!

(Luckily I had a spare A123 on hand)

if the reg is set at 3.3v prior to connecting battery it shall not go over
this is the principal of this method

[rickmcinnis]

That is what I figured but with the voltage set at 3.3 it will not be maintained, either.

To get it to stay at 3.3 I have had to raise the voltage and then when the computer is no longer running, if you leave the chargers connected, the voltage would rise, One night I left them on all night and I feel sure that is what did it.

Does this indicate to you that I have done something wrong?

Of course, setting the regulators with no load is not a real setting but have you found you COULD leave your floaters on all of the time if you wanted to or will you, also, get a creep up?

What VA are your transformers for 3.3 and 5? I thought I was using ones of reasonable capacity but they do run more than a little warm. Maybe I need larger ones? I think I am using 6.3v 8A for 5 volts and 5v 10A for 3.3.

[nige2000]

That is what I figured but with the voltage set at 3.3 it will not be maintained, either.

To get it to stay at 3.3 I have had to raise the voltage and then when the computer is no longer running, if you leave the chargers connected, the voltage would rise, One night I left them on all night and I feel sure that is what did it.

Does this indicate to you that I have done something wrong?

Of course, setting the regulators with no load is not a real setting but have you found you COULD leave your floaters on all of the time if you wanted to or will you, also, get a creep up?

What VA are your transformers for 3.3 and 5? I thought I was using ones of reasonable capacity but they do run more than a little warm. Maybe I need larger ones? I think I am using 6.3v 8A for 5 volts and 5v 10A for 3.3.

guess the current capability of the floater supplies isnt enough
voltage should be stable today, tomorrow pc on or off

30 or 50 va tx

[rickmcinnis]

Mine might be too small - just over 30 I think.

I figure with the big 3.3 I will move the memory power from the 5 volts.

I found a LINEAR TECH 3 amps regulator that might be useful - seems to be made with batteries in mind. Ordered one of those and a 100VA transformer - hoping that will keep up with the power needs.

[rickmcinnis]

Got a 40Ah battery for 3.3 rail and tried to see if it would be able to supply the BELLESON reg for the memory along with all of the regular duties of the 3.3 rail.

The graph at their site said it would not be enough and sure enough it was right. The definition of a high dropout regulator.

Have two more on the way for the 5 v rail. Might be able to run for a little while without the floaters? I will know Tuesday.