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Old 27th March 2014, 10:29 AM   #21
sesebe is offline sesebe  Romania
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Quote:
Although I can't speak for it as I haven't tried myself, but many who have tried a USB optical isolator (like the Adnaco S3B) have said it's better than a regular motherboard USB connection, but not better than some specialty, linear powered USB cards; most of which cost less than the Adnaco. They claimed a lack of timbre, realism, or nuance to the music, in comparison.
You compare apples with pears. Both are good but the taste is different.
In fact you compare diferent (IC) DAC's with diferent output stages.
For an exact comparison you must use "exactly" the same DAC, the only difference should be how you isolate the connection (ground loop) or the power supply type, but not both of them simultaneously changed.
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Old 27th March 2014, 12:59 PM   #22
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Quote:
Originally Posted by Julf View Post
So just to be clear, you are worried about using a switching power supply to feed something that only consists of switching circuits?

Absolutely! RF radiation off a competently designed MB is not a serious issue, where the pico/nano appear to radiate a lot worse than even a standard ATX supply.

I don't pretend to understand what exactly is going on with noise -whether is the radiated noise, the ps noise, or the noise appearing on the usb data lines, which makes the most difference soundwise.
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Old 28th March 2014, 01:18 AM   #23
BonkM is offline BonkM  Canada
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Quote:
Originally Posted by lexer98 View Post
- In fact is worse because you lose the BIOS control and complicate the things.
- The only thing that can affect the audio are the power circuit of the CPU, chokes oscillate at 300-400Khz, but your MB is a really good one

In my opinion don't change anything related with the MB.
Thanks for telling me that, I never considered that if I did power my RAM with a linear supply I'd lose BIOS control. You're absolutely right. Hmm, I'll have to think about it now. Thanks :-)

Quote:
Originally Posted by sesebe View Post
In fact you compare different (IC) DAC's with different output stages.
For an exact comparison you must use "exactly" the same DAC, the only difference should be how you isolate the connection (ground loop) or the power supply type, but not both of them simultaneously changed.
I agree, it only makes sense to change one at a time, or else you won't be able to accurately tell what made the difference.

And actually, what I said was that I hadn't tried it before, but some other people had. When they were talking about it, I assumed, they kept their system the same and only changed the USB->DAC connection.

In that case they first listened to
1. standard motherboard USB
and then
2. Adnaco SB3,

Then they tried
1. standard motherboard USB
and then
2. Specialty Audio USB card

And finally
1. Specialty Audio USB card
and then
2. Adnaco SB3.

Their results were:
Best: Specialty Audio USB card
Better: Adnaco SB3
Normal: standard motherboard USB

So, I haven't tried this myself, but I do agree than logically the optical isolation of USB should be a good thing. From what I've read it is a good thing, but not the best thing. I have since bought a Specialty Audio USB card, so that's the path I'm going down now. No optical for me, unless someone I know buys a unit and lets me test it out in my system :-)

Quote:
Originally Posted by analog_sa View Post
Absolutely! RF radiation off a competently designed MB is not a serious issue, where the pico/nano appear to radiate a lot worse than even a standard ATX supply.
Yeah, people who've really given the PICO a going over haven't touted its sonic attributes. It is damn convenient, though, isn't it?! I REALLY wish I could use it, it would make life A LOT easier, but it's just not in the cards.

Quote:
Originally Posted by analog_sa View Post
I don't pretend to understand what exactly is going on with noise -whether is the radiated noise, the ps noise, or the noise appearing on the usb data lines, which makes the most difference soundwise.
Me too, I've got not idea, and I haven't had much opportunity until now to start trying it out myself. I can only go off what others have said here and there and then hope connect a dot or two. Let's hope this road I'm going down now teaches me a bit about the topic.


How about those transformers, though? Have any of you guys done anything with the AMB - Sigma11 or Sigma22 boards?
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Old 1st April 2014, 02:52 PM   #24
BonkM is offline BonkM  Canada
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So, nobody has any experience with making or buying some kind of voltage timing board? One that could supply certain voltages in a certain sequence?

And no one out there has any experience with the AMB σ11 or σ22 boards? Or picking what kind of toroidal to go with for a certain voltage?

Or how about recommended toroidal transformer manufacturers?
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Old 1st April 2014, 05:27 PM   #25
sangram is offline sangram  India
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FWIW I did this on a much smaller scale, using a linear supply for a bedroom audio PC based on a Cedar Trail processor. I think they're called Cedar Trail because they're made of wood chips, they're that slow!

Anywhoo, it made a mild difference, but maybe that's because the Coolermaster 'universal' laptop supply I bought for it was really junk. This is one of those 19V motherboards referenced to earlier.
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Old 4th April 2014, 04:35 PM   #26
Crom is offline Crom  United Kingdom
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BonkM, I have done this and wouldn't look back. To the cynics here I will say that I was with you until I tried it and now I'm no longer a cynic. Make sure you have low wattage CPUs and it's a lot easier if you have a motherboard that is not to fussy about sticking to the ATX spec power supply. I use an Intel DH61DL and this doesn't need any of the ATX control voltages. Literally supply +12, +5 and +3.3 to the appropriate ATX MB connections and ground the power button header connector to turn it on. I've got a wapping great toroid that supplies the voltages and I used a PSU circuit that I found on audio asylum to build the different voltage rails.

Once you have that working have a play with underclocking the ram and CPU. Some people have reported that you will find a sweet spot (ie sounds best) when playing with reducing the voltages - go to far and it detracts from the sound...before not booting at all ;-). Once you're happy with it all then check what voltage the RAM is using in the BIOS and then look at the MB to find out where the RAM supply comes from. Then power this separately. I haven't bothered to do this with my current set up - it's icing on the cake stuff - but worth it if you've done everything else.

Instead of the RAM you can try other things:

1) Get rid of all fans, use passive heatsink
2) Get rid of hard disk and replace with ssd, CF or apparently OS on a USB stick is good but I haven't tried it
3) Power SSD and the USB that you use for 'audio out' separately. Who knows why but the quality of power to the OS SSD changes the sound a lot...yes, I know how this is starting to sound(!)

I have gone from linear supplies to now feeding the OS SSD and the USB card using lifepo4 power. Best I've had yet.

Good luck!
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Old 6th April 2014, 05:13 PM   #27
maro73 is offline maro73  France
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Hello
I have the intel motherboard dh61dl
Which life4power battery are you using ?
Cheers
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Old 10th April 2014, 02:23 PM   #28
Crom is offline Crom  United Kingdom
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I tried the Anker battery packs with a USB socket. Very easy to get 5v out of them by chopping up a USB lead. This was an improvement over a decent linear supply and very strangely using this power on the OS SSD had the most benefit. I then used various bunk-boost circuits (IIRC) and a few regulators to see if I could get 5v out of what are widely recognised as the best for audio lifepo4's:

Lithium Ion Cells | Cylindrical Cells | 26650 Lithium Cells

The best sounding - if probably not the best for the cells - was to just wire a decent 5v linear supply in parallel with 2 x cells in series, and the load. The cells need to be discharged to around 2.6v each. So that you end up with 5v from the linear supply and about 5v from the cells. Seems to work fine for the moment and none of the hassle charging up either. I'm still testing all this though!
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Old 14th April 2014, 01:27 PM   #29
SGK is offline SGK
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10A for the 12V rail? That's a lot. I have an ASRock Z87E-ITX with Haswell 4570T processor. I've measured the current on the 12V linear supply I have feeding the PicoPSU. Playing music including multichannel SACD it uses 1.1A. Playing video with JRiver set to Red October HQ it consumes 2.2A. Obviously if you want to add a stonking great video card to the setup it will consume more power but I haven't found a need to yet.

I was asking a similar question re quality toroids the other day. Somewhere on this site is a list of recommended manufacturers (Google DIYaudio recommended toroid transformers). Toroidy in Poland is recommended. Getting the required VAC is straightforward - just leave yourself plenty of headroom.

Have you decided what rectifier diodes you are going to use? Snubber on the secondaries and how to optimise? Which smoothing caps? Regulator?
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Old 14th April 2014, 01:32 PM   #30
SGK is offline SGK
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Quote:
Originally Posted by analog_sa View Post
It is not a good sounding solution at all. Something similar to the Pico (Nano) prompted me to build a linear supply. Admittedly, for a very low power i3, but it made a very substantial difference soundwise. There was a thread about it somewhere...
Didn't you find that the greatest gain you experienced was from supplying the PicoPSu with clean 12V and that the next step into a full linear PSU was a modest further gain?
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