Paul Hynes Power Supply for Logitech Touch

[MartinT]

As an alternative to buying a ready-made power supply for my Touch, I built one using Paul's latest PR3i-5 module, set for +5V. This is a rework of the highly successful PR3 as used in my Bushmaster power supply (in that case, a PR3-16).

It's very easy to build a project based on the PR3i when ordered in 'energy storage' version, where rectification and reservoir capacitors are all on-board. All that is required is a 6-0-6 50VA transformer (I used a Multicomp from CPC), a project case and some connectors, wiring, terminal block etc.

There's no need to go into a detailed build sequence as it's pretty straightforward. I used Paul Hynes Clearsilver XL cable as the mains feed into the PSU - captive this time as I find cutting holes for IEC sockets painful.

The case is the heatsink since the module barely gets luke-warm when powering the Touch, with a little heatsink compound to aid heat transfer. I left the unit on soak test for a while and adjusted the output for a perfect +5V output.

Showing 'fitting up' the main components into the case before drilling. I used the same Maplin case as for the Bushmaster PSU. Some medium size sorbothane feet help isolate the PSU from vibrations.



The finished Touch PSU (right) got a green LED to differentiate it from the Bushmaster PSU (left).



The Paul Hynes PSU helps elevate the Touch to a serious high end streamer, especially with the EDO applet installed to enhance digital output to the Bushmaster. The sound is highly detailed with absolutely no harshness and a low noise floor. I have a test track recorded at -70dB and that is a stiff test of DAC linearity and noise floor. It was still recognisable as music when the volume was turned up way high, a very good test of low level detail resolution.

Hi-res files sound extremely fine, again with that combination of fine detail and non-harshness. The ultimate limit to sound quality now appears to be the Bushmaster itself, no bad thing since it's a very fine DAC. The point being that the Paul Hynes PSU with Logitech Touch form a low cost file streamer of great value for the DIYer.