Power Supply for Squeezebox Touch

[Lar]

Anyone have any info or links for DIY power supply for Touch? 5v 3A. Any info much appreiciated.

[btrancho]

Anyone have any info or links for DIY power supply for Touch? 5v 3A. Any info much appreiciated.

If you haven't already done some searching over at the Slim Devices forum, I suggest you spend some time there.  The older SB3 really benefited from changing the power supply but opinions are very divided over how much (if anything) is gained with the Touch.  The Touch has an internal switching supply in addition to the wall wart and many believe that little is accomplished aside from perhaps limiting noise feeding back into your mains.  I put a linear on my Touch and perceived no difference in sound at all.

Anyway, it would be best to head over there and do a search in the Touch forum for power supplies, linear power supplies, etc. to see all sides of the issue and make up your own mind.  IIRC, John Swenson over there has posted plans/schematics for what you might be looking for. Here's the schematic.

http://forums.slimdevices.com/showthread.php?t=82648&highlight=power+supply+schematic
http://forums.slimdevices.com/showthread.php?t=79977&highlight=power+supply+schematic

[mrarroyo]

I am using an older (refurbished) Red Wine Audio that uses SLA batteries with a regulator to power an SB Touch. Happy with the blacker background and effortless punchy output via the 1/8" headphone plug and the RCA's.

[InfernoSTi]

I use a modified Jerome linear power supply for my SB Touch.  I understand they are now discontinued.  Wayne over at Bolder Cable Co. has a lot of great ideas/products for the Touch and other such products:  http://www.boldercables.com/servlet/StoreFront   Take a glance at his storefront or check him out on AudioCircle for some ideas, perhaps.

John

[earwaxxer]

If you are using the DAC in the Touch IMO you would be best served to get a better DAC and use the Touch as the server/transport. Modding the power supply is not going to get much bang for the buck. For the jollies I would build a NMH battery pack and see if it makes a difference. Not sure how sensitive the Touch is to voltage variation though.

[InfernoSTi]

These issues are highly debated (just see the attempts to discuss the Mac Mini) so I don't want to get into a back and forth.  Of course, here I go with my post, anyway, right? 

However, I have found based on my personal experience that the stock SB Touch is less than what I would listen to with even a modest off-board DAC.  However, once I had my Touch modified by Wayne (I did the "digital" mod and the power supply mod, including Bybee Music Rail), the change was dramatic.  It would be very easy to A/B if someone had a stock SB Touch...I have no doubt that every single person would prefer the modified Touch and not by a small margin. 

There are different levels of modification as well as different types of modifications possible. These include the Touch itself (modifying the digital side, the analog side, and the internal power supply) as well as the external power supply (linear, linear plus better filters, linear plus better filters and Bybee Music Rail).  There is even a simple analog mod for under a hundred bucks that, when combined with a linear power supply, would be a noticeable change.

I was impress by the impact of well designed mods to the Touch.  YMMV

John

[Lar]

Thanks for all the feed back, i think i will do more reading. its all about choices and $.

[earwaxxer]

These issues are highly debated (just see the attempts to discuss the Mac Mini) so I don't want to get into a back and forth.  Of course, here I go with my post, anyway, right? 

However, I have found based on my personal experience that the stock SB Touch is less than what I would listen to with even a modest off-board DAC.  However, once I had my Touch modified by Wayne (I did the "digital" mod and the power supply mod, including Bybee Music Rail), the change was dramatic.  It would be very easy to A/B if someone had a stock SB Touch...I have no doubt that every single person would prefer the modified Touch and not by a small margin. 

There are different levels of modification as well as different types of modifications possible. These include the Touch itself (modifying the digital side, the analog side, and the internal power supply) as well as the external power supply (linear, linear plus better filters, linear plus better filters and Bybee Music Rail).  There is even a simple analog mod for under a hundred bucks that, when combined with a linear power supply, would be a noticeable change.

I was impress by the impact of well designed mods to the Touch.  YMMV

John

wow! Thanks for the insight John - I think many in the audiophile community were under the impression (ex. Stereophile) that the bit perfect delivery from the Touch was, well, perfect! I was a bit skeptical and have duly added your impressions to the data bank.

[BNAL]

If you think about it the biggest improvements come from power supply upgrades. Even the upgrades to the BH products are for the most part power supply upgrades. Granted there are things like cap and resister upgrades to the signal path, but in my experience the upgrading the PS makes the biggest difference. 

[2wo]

I think Eric's suggestion of cobbling up a battery supply, is a good one. Give you a quick read on whether its worth pursuing...John   

[InfernoSTi]

wow! Thanks for the insight John - I think many in the audiophile community were under the impression (ex. Stereophile) that the bit perfect delivery from the Touch was, well, perfect! I was a bit skeptical and have duly added your impressions to the data bank.

Eric,

I'm not trying to pass myself off as an expert...I certainly am not.  However, I decided to try the Touch mods after (1) owning a Touch for over a year and (2) basing my mod path on the recommendations of others whom I have learned to respect based on shared experiences or overall philosophy.  I'm so much happier with my Touch today than I was before.  Here is a quote from Klaus with Soundcheck:

The myth that "0s are 0s and 1s are 1s -- it's all digital don't care about" is simply said wrong and misleading.
It's not about just digital 1s or 0s actually. The data receiver must be able to read a certain analog voltage and need to declare it a 1 or 0. Since timing and shape of that bit and its distortion are continuously changing and usually far far away from being ideal, the receiver will see all but a clean rectangular evenly separated noise-free signal.  In the majority of cases the situation is that bad that a receiver is not able to recover respectively refresh that incoming bitstream properly.

If people are talking about bit-perfection or bit-transparency, it won't tell you anything about the actual sound quality. Bit perfection just says that the value of a bit (or sample) arrived as it was sent - as a 1 or 0 - but it doesn't say at what time resp. in what condition it arrived (or even it's reflection arrived) and if and how the receiving end is able to cope with that condition. And that's a key issue. The vast majority of  DACs out there are just not able to properly cope with quality issues on the incoming bit stream respectively connection.

The link to the above quote: http://soundcheck-audio.blogspot.com/2011/11/touch-toolbox-30.html

Kind of an interesting twist on the "bits are bits" argument.  And that doesn't even get started with the power supply side of the story...which is really where things get exciting! 

I hope you enjoy this dialog....

John

[Lar]

Yes i`m interested in seeing where i can take my Touch. At present it sounds pretty darn fine, but i know it could be better. Power supply is really of interest to me. The journey continues.

[Doc B.]

John Swenson, who is designing the digital portion of the Bottlehead DAC, has quite a bit of experience with the Squeezebox and Touch. You might do a google search to see what he may have written on the subject. Like us, John believes very strongly in the value of excellent power supplies.

[btrancho]

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 it 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.

[Lee Hankins]

This should be close to what you are looking for:

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