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bingcrosby
2009-11-30, 08:52
Hey guys,

This is my first post!

I have heard that the switch-mode power supplies supplied with the SB Touch are not ideal as they generate RF noise. I will be using it only as a digital transport to play EAC rips and 24 bit files from a hard disk and USB stick. I am planning to hook this up to some Naim gear and they warn against RF noise and digital outputs with switch mode power supplies.

Does the re-designed digital output of the touch make finding a linear power supply unnecessary? If it still could represent an improvement, how does one go about finding a toroidal power supply for it?

Regards and thanks,

Peter.

Phil Leigh
2009-11-30, 10:57
Hey guys,

This is my first post!

I have heard that the switch-mode power supplies supplied with the SB Touch are not ideal as they generate RF noise. I will be using it only as a digital transport to play EAC rips and 24 bit files from a hard disk and USB stick. I am planning to hook this up to some Naim gear and they warn against RF noise and digital outputs with switch mode power supplies.

Does the re-designed digital output of the touch make finding a linear power supply unnecessary? If it still could represent an improvement, how does one go about finding a toroidal power supply for it?

Regards and thanks,

Peter.

Peter, there is no need to change the supply on the Touch. I have measured both the analogue and digital outputs (via a DAC) and there is no measurable difference at all with either between the stock PSU and a very expensive medical grade 5A Linear supply.


The only reason for changing the supply would be if you had an AM radio (?) nearby, as some of them can be susceptible to the RF. However, all other equipment should have adequate AM rejection.

JohnSwenson
2009-11-30, 15:33
I agree with Phill. The PS that comes with the SB3 spews stuff out all over the place. Getting rid of the direct radiated noise and noise injected into the AC mains is the main reason for changing it.

The PS that comes with the touch seems to be much better so there is much less need to replace it. I have run it off my specially designed linear supply which DOES make the SB3 sound better, but I could not detect any improvement on the touch.

I've done some simple EM field measurements around the touch and its supply and they are vastly lower than for the SB3 and its standard supply.

I would not hesitate to use a Touch as is.

John S.

bingcrosby
2009-12-04, 18:50
Thanks for your replies. Is there any difference in quality between the optical and coaxial outputs of the touch?

On a similar note would it be possible for somebody to recommend a powered external USB hard drive that comes with a power supply that doesn't emit RF all over the place?

DaveKen
2009-12-05, 07:46
Thanks for your replies. Is there any difference in quality between the optical and coaxial outputs of the touch?

On a similar note would it be possible for somebody to recommend a powered external USB hard drive that comes with a power supply that doesn't emit RF all over the place?

Try looking at the Beresford Caiman DAC at around 200+ a giant killer.
Dave.

bingcrosby
2009-12-05, 09:41
Thanks Dave but I am looking more for a HDD with a good power supply than a DAC (I will probably use the one in the Naim SUPERNAIT).

Is there a limit to the size of the external powered hard drive?

Phil Leigh
2009-12-05, 10:34
Thanks Dave but I am looking more for a HDD with a good power supply than a DAC (I will probably use the one in the Naim SUPERNAIT).

Is there a limit to the size of the external powered hard drive?

No, but it needs to be a single disk unit.

Todd R
2009-12-06, 07:18
Hey guys,

This is my first post!

I have heard that the switch-mode power supplies supplied with the SB Touch are not ideal as they generate RF noise. I will be using it only as a digital transport to play EAC rips and 24 bit files from a hard disk and USB stick. I am planning to hook this up to some Naim gear and they warn against RF noise and digital outputs with switch mode power supplies.

Does the re-designed digital output of the touch make finding a linear power supply unnecessary? If it still could represent an improvement, how does one go about finding a toroidal power supply for it?

Regards and thanks,

Peter.

Here's one: http://www.ciaudio.com/