Power Supply for Squeezebox Touch

[Lar]

This should be close to what you are looking for:

 http://glass-ware.stores.yahoo.net/lvregulatorkit.html

This looks interesting, thanks, and it won`t break the bank!

[InfernoSTi]

Below is a quote from one of John Swenson's posts on the Slim Devices Forum, directly addressing linear power supplies and the Touch (color emphasis is mine).  I agree that quality power should be the goal in good audio.  The question here is whether or not substituting a different DIY or third party power supply on the Touch improves the sound that the user perceives.  That perception can come from many sources and perhaps the reason some tell of improved sound is because of the noise that is not sent back down the AC line.  (I'm not going to start in with cognitive bias - that's a whole other thread fraught with minefields...)

My conclusions are that a large percentage of improvements with PS design for the Touch are related to high frequency noise sent BACK into the mains and picked up by other components. power sent into the Touch itself has little impact on what goes on inside the Touch (not zero, but quite small). The differences in mains injected noise is vastly greater than any changes in the power actually delivered to the components inside the Touch.

Given this the focus of PS design should be on decreasing what gets sent back down the AC line, not making the absolute lowest noise, lowest impedance feed to the Touch. Many of the attempts at getting the "best" power to the Touch increase the noise sent down the line.

For a linear supply there are primarily three things that contribute to noise sent back down the line: reverse recovery noise when the diodes switch, transformer ringing and current spikes when the diodes conduct.

I perceived no change in sound when I substituted a linear supply.  Perhaps it was the supply I chose. Perhaps is was my home's AC service.  Perhaps I didn't expect to hear any change to begin with.  I'd encourage Lars to look at John's design and read the entire Linear Power Supplies thread on the forum.  Strong opinions all around but generally civil and informative.

This is very interesting.  I wonder if the improvements I've heard (and believe anyone would hear) are more the result of the reworking of the internal power supply as the weakest link in the chain?  Here is what I had Wayne do to the Touch: 

The mods start out with improving power supply delivery and decoupling to the critical digital sections. We then install a custom voltage regulator circuit just for the digital output section and clocks.

Perhaps if you haven't done this, the rest doesn't matter.  That would then make the external PS much more critical as the next weak link and that is why my results were different.

John

[earwaxxer]

Interesting about the noise getting back into the mains from a device. I noticed my SMPS for my t-amp possibly contributing noise - I think my battery powered Quickie was picking it up! Even though the power supply was many feet from the Quickie. When I switched out to battery the noise went away.  I also spent a chunk of change on my JPS Labs digital power cord based on some of that logic. I use it on my Transporter. I think it did make a "significant" difference (clarity, resolution) although it was not my highest value tweak.

[HF9]

This should be close to what you are looking for:
 http://glass-ware.stores.yahoo.net/lvregulatorkit.html

I just purchased one of these myself, along with a Hammond transformer and a small aluminum box to make a power supply for a Wadia 171 iTransport. Granted I don't have tons of knowledge on the subject of power supplies, so I'll be doing some reading before assembly. It's nice to know why things work the way they do

[BNAL]

This looks like a nice power supply option (SR1-MR ) for the SB.
http://www.paulhynesdesign.com/page7.html

[Tubejack]

I own one of these for my SB Touch .... works very well.

http://www.welbornelabs.com/squeeze.htm

[grufti]

I wish every linear power supply was built like this. I don't know what he does for a living, but Mr. J. Swenson knows power supplies.


(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fjohnswenson1.home.comcast.net%2Fstereo%2FSB_5V.GIF&hash=bb8fc0a00b6ebf4f6a17b654e0d3f0a7234b444b)


This power supply models quiet and it tests quiet when built. Thanks for pointing it out. I might go with a different transformer, possibly a Hammond 229Cxx where xx is voltage, but that has to do as much with availability as it does performance. It is fairly easy to substitute other regulators for different output voltages. Very, very nice indeed.

[grufti]

Sorry, no wonder, I now read the part where John Swenson explains his job responsibilities in the same thread: this is a power supply designed by someone who designs way more complicated power supplies for a living. You can make this a commerical design and never look back.

Not cheap, by the way, a nice transformer and the choke alone will set you back about $60 at single unit prices, but nothing that good is ever cheap. The size of C2 is a huge factor in the design and how about those 20A Schottky diodes in a 1A power supply. Those don't add much to the price either. Did you notice the three different kinds of Panasonic caps: FC, TSHA, FM, FM? This is almost too good to be true.

[Laudanum]

I dont know alot about the Squeezebox or this stuff in general, but wouldnt a kit like this work for it?  ... http://www.amb.org/audio/sigma11/

I have a digital player that runs off a battery or a wall wart.  The sound was noticeably better off the battery than compared to the wall wart although describing it is not my forte.   
I built the sigma 11 using decent parts and was pleased to find that when powered by my completed project, I heard no difference between the battery and the power supply. 
It wasnt a very expensive enterprise so was well worth it for the extended playing time.  Again, I dont know if it is appropriate for the Squeezebox.

[Lar]

I wish every linear power supply was built like this. I don't know what he does for a living, but Mr. J. Swenson knows power supplies.


(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fjohnswenson1.home.comcast.net%2Fstereo%2FSB_5V.GIF&hash=bb8fc0a00b6ebf4f6a17b654e0d3f0a7234b444b)


This power supply models quiet and it tests quiet when built. Thanks for pointing it out. I might go with a different transformer, possibly a Hammond 229Cxx where xx is voltage, but that has to do as much with availability as it does performance. It is fairly easy to substitute other regulators for different output voltages. Very, very nice indeed.

If it was translated into a manual that looks like Doc`s i would build it, otherwise i`m lost. ):

[Grainger49]

Thanks for posting this schematic.  I'm saving it for projects that might need it.  

The filter on the secondary side of the transformer, the RC, is a very nice touch.  I think it functions like the old RRSF of Seduction and FP 2 circuits.  It was a FP 2 upgrade that became a stock part of the Seduction's circuit.  It absorbs the noise from reverse leakage of each diode.

Changing the transformer voltage and the regulator voltage would make this appropriate for all sorts of things (keeping in mind the cap voltage rating might need to change if you go above say 25V input).  I'm wondering if the choke needs to change for anything but the circuit current rating.

[Noskipallwd]

Lar,
Sorry I did not see this thread earlier, there is a DIY ps for the Squeezebox at www.teddypardo.com. I have not built or used it but I do know a few people that like it on their system.

Cheers,
Shawn

[Lar]

Lar,
Sorry I did not see this thread earlier, there is a DIY ps for the Squeezebox at www.teddypardo.com. I have not built or used it but I do know a few people that like it on their system.

Cheers,
Shawn

Thanks for the link, but i already have one just about done. Its the LV - Regulator, i figured it has my initials i should build it.

[Noskipallwd]

Great job Lar! I bought my SBT with a CIaudio ps as a package deal. I just picked up a nice 128GB ssd that I converted to USB, I plan on using either a Sheevaplug or a Goflex net to make the SBT a stand alone server with no computer required.

Cheers,
Shawn

[Lar]

Great job Lar! I bought my SBT with a CIaudio ps as a package deal. I just picked up a nice 128GB ssd that I converted to USB, I plan on using either a Sheevaplug or a Goflex net to make the SBT a stand alone server with no computer required.

Cheers,
Shawn

Interesting idea with the Sheevaplug or Goflex, is that 128GB drive big enough? I find with my High Res music files take up lots of real estate.