Investigating a full linear PSU for the XXHE PC and NOS1

[acg]

Hey Bert - Do you mean such a beast like e.g. Mani has ?

Something like that but smaller will do as well as long as you do not connect all your PC's to that one transformer... ;-)

I am using a 1000VA for both my PC's (and related switching adapters), one monitor and one Behringer.

http://www.amplimo.com/index.php/products/safety-transformers-for-medical-use

Bert

There is a good thread going on these things over on my local forum at the moment.  A product made in the UK has fared very well in the value for money stakes.

Anthony

[BertD]

http://www.amplimo.com/index.php/products/safety-transformers-for-medical-use

BTW, never use these type transformers to connect your amplifiers too. It is tempting but it makes the sound dull...

...unless it is a HUGE one. ;-)

Just use it to keep your own mains clean(er) by not adding.

NOTE The internal earth shield is one very effective part of this transformer...

[PeterSt]

Now let me see ...

So with my good senses (which may be worth nothing in the first place) I say that this is all about spitting back in the mains. So, I get myself such a transformer plus a couple of fuses and resistors plus some sort of cabinet and my issue of concern is solved ?

Hmm ...

[PeterSt]

Ignorant me again ...

So, can anyone tell me how such an "isolation" transformer would isolate any back fired spikes and such ?
IOW I don't believe that.

I am not sure at all how that would work from the secundary to the primary but from the primary to the secundary it would work no different than a TVC for example, or any transformer based attenuator. And that such a transformer lets true all the AC it is fed with is a good thing for our audio.

Maybe in this case (secundary the same voltage as the primary) the whole thing can even be connected the other way around (but not sure here). If that is so it tells enough already.

So ?

[BertD]

So, can anyone tell me how such an "isolation" transformer would isolate any back fired spikes and such ?
IOW I don't believe that.

It removes spikes generated by switches (transformer connected to isolate the audio equipment) so something get's lost in there! ;-)

Bert

[BertD]

Now let me see ...

So with my good senses (which may be worth nothing in the first place) I say that this is all about spitting back in the mains. So, I get myself such a transformer plus a couple of fuses and resistors plus some sort of cabinet and my issue of concern is solved ?

Hmm ...

I can take it with me next time I visit? Easy to take out and for you easy to measure the "differences"?

Connect a PC and "see" what happens at both ends of the transformer?

Bert

[PeterSt]

Bert, great idea.
Peter


PS: All I can think of is that high transient spikes (or very high frequencies) won't come through so easy just because a transformer is not fast enough.
But might you have referred to general "switching" (like from light switches or anything) now not being audible anymore - I don't think so. This is all ground loop stuff or lack thereof (remember our dishwasher story while one of the XLR pins was not connected ?).

[BertD]

But might you have referred to general "switching" (like from light switches or anything) now not being audible anymore - I don't think so. This is all ground loop stuff or lack thereof (remember our dishwasher story while one of the XLR pins was not connected ?).

It always made noise when I turned on the big light in my room (12 TL tubes). The moment the transformer was connected in "series" that noise stopped.

Perhaps more things were changed at the same time (that's me!) but that noise was gone.

The dishwasher was just having NO ground at all (floating) and that is acting as one major antenna picking up things out of the air, not the mains.

We will figure it out soon enough...

[Nick]

There is a good thread going on these things over on my local forum at the moment.  A product made in the UK has fared very well in the value for money stakes.

There are a few members using the AirLink balanced transformers and more experiances in a thread on the forum.

I have ended up with couple of 3kva AirLink balanced transformers (as tested in the link above). They do make a really significant difference to sound quality and I generally agree with the tests findings on the AirLink. Paul and Mani also use them although I think Mani has 2X 5kva model IIRC. One thing that is worth bearing in mind and possibly not covered by the test is that the sound quality improvements are pretty much doubled (subjectively) if a dedicated audio system PE is setup with the AirLinks using an earth spike.

I also have some 2KVA single ended mains isolation transformers but compared to the AirLinks these are nowhere near so effective so I think a the balanced isolation transformer design is really worth the effort and cost.

The two 3kv AirLinks transformers power all of my audio system. PC, DAC and Gainclone amps are plugged into first AirLink and my active Subwoofers are plugged into the second AirLink. Placing the subs on their own AirLink makes a big difference. I agree with Berts view (below) that placing the "main amps" on the same isolation transformer as the rest of the audio system make a dull sound. This in the end was the reason for buying the second AirLink unit.

Its interesting that to obtain the best sound, I need to have my PC DAC and Gaincline amp plugged into the same AirLink unit. This seems to suggest that a common mains power reference point for these components is more important than the possible negative effects of hash being put back into the mains supply by the PC, DAC and Amps.

As you can tell I'm a big fan of the AirLinks  .

Cheers,

[Scroobius]

I have been using the AUDIO GRADE USB 3.0 PCIE CARD powered from the 5v supply from my PC Seasonic power supply. The performance is just superb (what? don't tell me that you haven't ordered one yet) it is fundamental in the performance of my system now.

Anyway how can such a fine piece of kit (the PCie card that is) sound any good powered by a switched mode PS?. So I got hold of a 5v linear power supply. The spec of it look promising (ripple 5mv) not that that means anything without looking at it with a scope. Anyway I hooked up the linear supply to my AUDIO GRADE USB 3.0 PCIE CARD - and sat back in amazement. It just did not sound right - a glassy edge (jitter?) returned to the music - the beautiful flowing detail had gone. So I went back to the SMPS - much better back to the beautiful flowing detail again.

I have to say that was a surprise I expected maybe the same(ish) or slightly better but not worse. I am going to have to have a look at what is going on with a scope.

Maybe the supply needs running in but it has a long way to go get to be even as good as let alone better than the SMPS.

I will try powering the clock with 3.3V battery power - but I will have to tear myself away from listening to music first so not top priority just now. Maybe when I go to see Nick again later this month.

Odd!!!

Paul

[acg]

Paul, I _think_ that noise is more important than ripple for a USB card, which when you think about it the entire reason to use that USB card is to reduce noise making its way along the USB cable.  Not all linears are created equal, which may be why the modder of that card recommends a battery supply...but I am hoping that I (well Peter probably) can produce a definitive very low noise supply for that card.

Anthony

[PeterSt]

I merged the discussion about this PCI USB card (and source of noise to counteract) to here : Re: Great PC Tweak - A Bert "Must Have".

Peter

[Scroobius]

Hi Anthony - I understand and agree about the noise aspect and I think Nick's previous posting about it points clearly in that direction but as I had a linear supply to hand I thought it would be worth a try as it only took a few minutes to set up. Well it should have only taken a few minutes if I had not corrupted my BIOS doing it 

Always good to see more than one "Nosser" getting the same results.

Cheers

Paul

[PeterSt]

FYI : Windows 8.1 consumes 2.5W more everywhere (idle, playback etc.). I don't see how yet (cpu usage etc.) but it really does. Checked MinOS only.

Peter

[PeterSt]

Anthony, I have a small question for you :

The other day I was watching the usage meter when Windows 8 was idle (no playback going on) and saw a usage of 4 Watts. I am not sure anymore how it fluctuated but anyway it did and the meter was just alive. This was for a shorter while like 10 seconds. Then it went back to normal.

Did you see anything like this ? At the time I thought it was possibly a fault of the meter and I didn't pay further attention to it. Saw that only once.

Yesterday, a while after I installed Windows 8.1 and being in MinOS (I think for the first time), I saw it again. This time I watched closely, and usage showed 4W as te base but it could jump to 7W or 9W. I was looking at this for maybe 45 seconds before I went elsewhere (or did something to the PC - could be playback) and after that never saw it again (once in a while looking).

I don't think it can be true anyway, unless you have seen similar ...

My PC never hybernates or anything and monitor is always on (for OS settings). The only disk in there (OS disk) can spin down (also during playback) but it would be very coincidental like once per hour it may for a few seconds. So it could be that situation (because rare and hard to catch) but then it would imply (much) more going down (using 46-48W less suddenly ?).

Peter