Squeezebox Duet Fikus mod need advice!

[essencez]

Okay this all started when I first discovered noise through my PC’s coaxial output from this card.



Noise is only audible with my amp nearly maxed out but it still annoyed me.
To isolate this noise I’ve tried with various other sources and at the very end the coaxial input was the culprit. For some reason even with the coaxial input connected will generate the noise even with a different input selected on my amp!

So I switched to the SPDIF output and voila problem solved. Then I had a thought, since SPDIF is on the same card the noise is probably still there just I can’t hear it so I began looking for a better transport.

As I can’t buy a new transport (currently saving for a First Watt amp) I begin looking around for alternatives. I found my squeezebox duet lying around unused and did a bit of researching. Then I found this mod by Lukasz Fikus.

squeezebox

I read this makes the Duet “beats the 5000 dollar...” I was excited, and it had graphs! Must be true. I quickly read over instructions/parts, it turns out the mod is very simple and inexpensive to boot.

Then it turns out my Duet and Mr Fikus duet was slightly different, namely the three legged regulator doesn’t exist on my board.





I looked around for other ways to clean the power that the Duet was receiving and every audiophile grade PSU was more costly then the Duet itself then I had an idea. I have always remembered the cleanest power was power that is already in DC and did not need converting, thus a battery. This should do it, a fairy cheap 8500mAh at 9VDC.

15000mAh Portable Rechargeable Lithium Battery Power DC 12V 9V USB | eBay

As I was looking for the missing three legged regulator I looked under the wireless card and although I couldn’t find it I found other similar connections namely 3V3 and 1V2.





This first time I’ve soldered such small joints so I tried to simplify the steps.

1. Add a 100uF/10V to the red areas.
2. To improve the SPDIF, Remove R102 > Add 220nF 630V > 200ohm resistor > RCA centre pin > 75 ohm resistor > GND
3. Going to leave the yellow/LAN area alone, if my Duet lives through the first part I am happy!

I had a few questions I wasn't too sure of before I proceed with the mod.

1. Would adding caps in locations under the wireless card help out? And if so, would the same ones suffice (100uF/10V). I can probably easily loop 1V2 to the side of the card, 3V2 will be a little bit tricky though.
2. Since I will be using a battery, as the source of power for the Duet, are the changes, namely red ones necessary?
3. I plan on using the Duet strictly as a digital transport am I modding areas that I do not need improved?

Also I’ve included links to the parts I plan on using. I have no idea what I am doing except this is suppose to make my Duet sound like 5000 dollars any help/advice will be welcome, thank you. And thanks again to Lukasz Fikus for instructions a kid can follow!

100uF/10V Cap
220nF 630V Cap
200Ohm Resistor
75Ohm Resistor

Edit: Disregard the links above seems like I didn't do my homework guess there is no point upgrading with bad caps so I have ordered the following:

Step 1: 1x Mundorf E_Capacitor_073_BR63 220uf / 23VAC-63VDC
Step 3: 2x Mundorf E_Capacitor_066_BR100 47uf / 35VAC-100VDC
Step 4: 1x Mundorf F_Capacitor_103 MKP- 0.22uf / 630V, M-CAP® MKP Series
1x Kiwame Resistor_66167 200R / 2 watt
1x Kiwame Resistor_66157 75R / 2 watt

Edit 2: removed LAN power cap upgrades as they won't fit.