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Raspberry Pi Power supply

Posted: Tue Mar 24, 2015 9:55 pm
by terrybooth
I've wondered whether upgrading the Raspberry Pi power supply would have any impact on the sound it makes. The Pi is powered by a little Wall Wart power supply and I'd often wondered if putting something a little beefier there would affect things. Now, courtesy of setting son, I know.

He and a mate popped round to listen to the Cubix. He brought a DIY power supply along to try. Now, other than wiring a plug and a bit of house cabling, I know nothing about electrics, so apologies if I get this wrong: what we had was a 240 v to 9v AC transformer feeding a power supply/circuit bought complete off ebay to convert the 9v AC to 5 v DC. This was then fed into a USB cable to supply the Pi.

What it did was to 'clean the window' a bit more - everything was a bit more defined and the sound stage a little wider. (Not always a good thing: I noticed on a track I was very familiar with what sounded like the producer changing the level of part of the mix rather clumsily.)

In the past, I've fiddled around with different DAC boards and different PI versions, but they haven't made as much difference as changing the power supply in this way.

So, this looks like my next project.

Re: Raspberry Pi Power supply

Posted: Tue Mar 24, 2015 10:04 pm
by Dr Bunsen Honeydew
Very much so, send it to me with explanation of voltage needed etc with some music on it and how to use it and I will do one for you in our PSU box.

I will swop one for an eventual slice of Pie. :mrgreen:

Re: Raspberry Pi Power supply

Posted: Tue Mar 24, 2015 11:11 pm
by alfer
What is a HiFiPi pray? Does it have a DAC on board if so which one? If not then the analogue 3.5mm socket output is pretty crap.

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 8:40 am
by terrybooth
I have three variants, but the one referenced in the OP is a model b with a Hifiberry DAC running Volumio 1.4.

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 6:57 pm
by Lazmo
Dr Bunsen Honeydew wrote:Very much so, send it to me with explanation of voltage needed etc with some music on it and how to use it and I will do one for you in our PSU box.
Interesting could this Power supply for the Rasp Pi be an inclusion to the NVA range doc ? seems like it could be very lucrative for you if so and i would be interested

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 7:18 pm
by terrybooth
The requirements for a power supply:

The requirements for the Pi are +5v 700ma. Most of the 'wall wart' power supplies are rated a +5v 1 amp or +5v 2 amp. Presentation is via Micro USB B socket.

http://www.raspberrypi.org/forums/viewt ... 0&start=50 for power
http://en.wikipedia.org/wiki/USB

Although the connection is Micro USB B which is used for data transfer and power, this is power only, so only pins 1 (+5V) and 5 (ground) are needed. the connector is tiny, so although solder plugs are available, it might be easier to 'adapt' a ready made cable. The usb cable needs to be around 1 metre.

What I would like to be able to do, later on, is to separate the DAC board (which is powered through the Pi) and power it separately. But one step at a time.

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 7:21 pm
by Dr Bunsen Honeydew
I don't know until I look at it and what is required.

I could do a PSU for anything that has these daft wallmarts or external batteries packs, even Beresford :lol: . All I need to know is what voltage and what plug. First one of any type though I would need the unit for a while to get the best solution.

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 7:25 pm
by Dr Bunsen Honeydew
You would be be much better off drilling the case to take a standard power lead grommet as I use in the PSU connection to Phono2 and wire some decent cable through the hole and to an XLR to connect to the PSU. I can do it here if there is room on the case.

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 8:07 pm
by alfer
A minimum current delivery of 2A.

Re: Raspberry Pi Power supply

Posted: Wed Mar 25, 2015 8:26 pm
by terrybooth
Problems of scale there. The Pi is a board the size of a credit card, the Micro B usb smaller than my smallest fingernail, so, even with a Dac card on top the case is pretty small and doesn't have a lot of room. However This doesn't matter that much because the PI 'cases' I have are just a top and bottom lid.

Image

Putting it all into a proper case (probably with a stepped attenuator) is a later project.

(Here's someone elses' http://www.crazy-audio.com/tag/hifiberry/ (scroll to bottom))

Some pics here down the page. https://www.hifiberry.com/forums/topic/ ... i-and-dac/ the bottom one is probably best - the Pi is the board at the bottom with the yellow and blue sockets on it.

So perhaps something like this http://www.bixpower.com/product-p/cnt-m10.htm to provide the Micros usb b connection and a 4 x 1.7 mm male connector. Or butcher the former and connect to XLR?