Simple power supply tweak using HDMI - amazing improvement!

[jesper]

Thanks Frank,
I like to learn too and learned a lot from others sharing their wins too. I still have to learn more about the RPi and programming it. I like to get a good Room EQ installed. Any tip on this is appreciated.

I have been tweaking speakers and audio equipment for quite some years, but I must admit these RPi:s are fun to tweak!

I have another tweak in the pipeline too - adding a Class A non-feedback balanced output direct from the DAC output. It´s LC Audio´s ZAPfilter 2, a really nice one. It´s without OP:s, just pure transistors. That might just set everything up into the strata...
Kind regards,
Jesper

[Audiohrdwr]

Jesper,
thanks for the info.
On the BOSS which uses 3.3V we have 4 caps:
1> 4.7uF ceramic after LDO
2> 22uF film
3> 0.1uF film
4> 0.22 F !!! Super cap. That's 220,000uF

We know that it takes about 50h to break in the film caps but from reports we got, it can take up to 2 weeks to break in the super cap.
Judging by your feedback and set up, you have golden ears and we don't doubt you heard an improvement after adding your 1.5uF capacitor but could it be that the capacitor in question was already broken in ?
Please confirm.
regards
Andre

[jesper]

Hi André,
The 1.5 uF polypropylene capacitor was not new but never used.

As you might be aware of, all capacitors of same size and materials does not always have the same specifics and characteristics in audio. What I used was a quality audio filter capacitor. Capacitors have different parameters and one important one is its inner resistance, which should be as low as possible, because it acts like a resistor in series. If that inner resistance is higher it blocks the delivery speed of electrons in and out of it and that, in audio, will result in a less stable voltage output. A wobbling output, even if very little, by my test results obviously disturbs the signal.

In this case the midrange improved noticeably, and it opened up the whole soundstage and especially voices became more natural and less "compressed".

If you have the BOSS DAC I urge you to try my two capacitor tweaks - it´s worth it! (at least if you have quality amp and speakers).
Kindly,
Jesper

[bertie]

Hi Jesper, these posts are so interesting!
If I had the slightest soldering skill I would have new capacitors soldered right way.
Still, at the rate new circuit boards are appearing I doubt it will be long until some manufacturer advertises a new 'low internal resistance' RPi with crazy-ass capacitors dwarfing the board and I will be their first customer.
I see you have an Emotiva processor, I use their stereo balanced XSP preamp and, like you, am very happy.
Thanks for posting your improvements

[Waluan]