Life of Pi

[terrybooth]

Ta. That's another experiment on the to-do list!

[Fretless]

Terry, Is this any better? It's a 5.2V 2A supply specially made for the Pi.

Should be in tomorrow.

[terrybooth]

Listen and see. I think a slightly more beefy power supply helps.

The other experiment I must do is to see if a 5v rechargeable battery power supply (sold to recharge mobiles) makes a difference.

[Fretless]

General weirdness and power supplies.

New wall-wart arrived in the post this morning. Hooked up the Pi and left it to settle in and finally got around to a listen this evening. The new supply is rated at 5.1V and 2A. The little bit of extra voltage is apparently to compensate for any loss due to resistance in the lead, so that the Pi gets a full 5V supply. The Sony adaptor I was using up to now was 5V and 1.5A - so I wasn't expecting a big change.

The difference is there and it is audible. Immediately the sound via the Pi/Hifiberry is crisper, more solid. And this is using the optical input into the Hegel DAC. I was playing the album 'Batik', gently intense acoustic Jazz with a trio formation of Ralph Towner on acoustic guitars, Eddie Gomez on bass and Jack Dejohnette on drums. Having done a serious comparison the other evening between the Pi and my newly-acquired Kenwood DP-4090 CD player, I was aware of the differences between the two and this gave me a good reference.

The Kenwood uses a patented system called D.R.I.V.E (Dynamic Resolution Intensive Vector Enhancement) which applies digital filtering techniques to improve the data lifted from a CD and enhance the small, subtle details in the sound signal. What comes out of the player is a solid 'analogue' sound which opens up Eddie Gomez's bass so it gets really natural and 'woody' and comes out towards you.
The Pi with bigger power-supply portrays the same recording in a different way: a flatter sound stage, but better defined - more accurate. And more lifelike than with the previous power supply - a noticeable improvement.

I moved the SSP digital coax link from the Kenwood onto the Pi and compared that against the Beresford Toslink. Surprisingly I preferred the Toslink here, whereas the Kenwood sounded better on coax than optical. So the SSP went back on the DP-4090 and I now have two inputs of comparable quality, both equally enjoyable with one more accurate (Pi) and one more lifelike/analogue (CD).

Really worthwhile checking the power supplies - even for a digital output Pi setup as I have. It seems that the extra half-Amp does make a difference and that a minimum of 2A is a must in order to get the best out of the Pi. There are several power options available and I have also seen one advertised as a low-noise option (via the Hifiberry site).

Now back for a relaxing listen with a glass of Merlot.

[Fretless]

Listen and see. I think a slightly more beefy power supply helps.

The other experiment I must do is to see if a 5v rechargeable battery power supply (sold to recharge mobiles) makes a difference.

Would this not suffer from a decrease in voltage/amperage as the batteries slowly discharge ?

[terrybooth]

Possibly. My thinking is to buy one that is suppose to be able to recharge a phone six or more times (i.e. as big as I can afford) to try.

[despearce]

I've been messing about with Pi and IQaudio PiDac for about 8 months now. A cheap regulator board (Audiowind from ebay) and 5v transformer make a significant improvement compared to wall warts. You can add a second one to power the PiDac (or HiFiberry dac) isolating the GPIO pins that take power from the Pi and using them to attach the second psu which improves it again (3.3v).

I've just started using Max2play as server/player software which i find much quicker to update libraries and in conjunction with a networked hard drive have access to a multitude of internet radio stations and all of my ripped flac files.

I rip flac from the main PC straight to the hardrive and control the Pi using an ipad via logitech media server. As for SQ it comfortably bests a Cambridge Audio dacmagic plus and Beresford Caiman (in my system with my ears) and has cost £120 for Pi, PiDac, 2 psu's and a case.

[Fretless]

Good advice, thanks. My 2A wall- wart has died after a week, I'm back to the 1.5A supply and notice the slight reduction in SQ.

Max2play is unknown to me, time to check it out.

My Hegel HD12 DAC only does DSD via the USB interface and I am trying to work out if I can get the Pi to run USB output as well as via the HiFiBerry.

[despearce]

Max2play is Squeezeplug (squeezeserver and squeezelite) with a internet browser front end and some nice other bits all packaged together and optimised to run on a single Pi. Costs £7.50 for the premium version which you need to access the audio from the i2s dacs and digi+ board...

[Fretless]

Just found a 2.1A charger in a phone shop. Plugged it in to the Pi and it works a treat. The sound tightens back up, solidifies and the detail is crisper and clearer again.

I see that chargers are also available at 3.1A - would it be possible to try those, or could I end up with burnt Raspberry Pie?