[How to do instruction] Raspberry Pi power Supply

[Listener]

Following Larry Moore's comments on separate power supplies for the Raspberry Pi and Allo Boss dac, I agree that a switching supply is fine for the Pi and a nice, low-noise linear supply is best for the dac. The point I would stress is that the switching mode supply for the Pi needs to be rather larger than the ones that are typically available and used, I recommend at least three amps at five volts (some suggest 5.1 or even 5.2 volts, the spec is 4.4 to 5.25). If anything is connected to the USB ports that consumes power, then preferably four plus amps. Most people are using supplies of two or two-and-a-half maps, which will just barely run the Pi and choke on surge loads. Beefier power supplies will shine when dealing with surge loads and cpu intensive loads like compiling moOde. YMMV, but I think that investing in a larger, better-built switching mode power supply rather than using those crummy, dime-a-dozen wall-wort usb supplies will improve all-around Pi performance; your Pi's power consumption is highly variable and adequate, clean power is, after all, the lifeblood of your Pi.

Best,

    John

[TheOldPresbyope]

... YMMV, but I think that investing in a larger, better-built switching mode power supply rather than using those crummy, dime-a-dozen wall-wort usb supplies will improve all-around Pi performance; your Pi's power consumption is highly variable and adequate, clean power is, after all, the lifeblood of your Pi.

Best,

    John

+1

[Listener]

+2. I went with a regulated linear supply.  I'm sure either are fine. This minor effort definitely yields great improvements!

I think that is fine. I do think that separate supplies are a good idea; linear supplies for both or SMP for the Pi and linear for the dac as long as there is enough spare capacity for the Pi. Larry suggests improvements from feeding power through the GPIO pins, which I have yet to try.

    John

[rikardo1979]

+1 
Good quality PSU is important for music systems. People are very often surprised how much the systems could sound with quality PSU

I using LPSU for my RaspDAC. It feeds the I-Sabre DAC board and RPi is feed through the GPIO.

RaspDAC on the right. LPSU for it is the black one on the left. The smaller one on top is the LPSU for my TT

[energyi]

Can someone please help me understand why a battery isn't a better option especially for the low cost? Seems to me that a battery will add absolutely no noise. Thanks.

Energyi

[JST1963]

Hi moOde fans,

[HemiRick]

Someone needs to look at the output of an Anker battery on an oscillscope and see if it is really as quiet as we think, I mention this because most have 3.7 volt battery and a DC-DC power chip to up to 5V. I'm wondering if this chip makes any noise?

[rongon]

Any idea how much maximum peak current an Allo Boss DAC draws? I see discussion about the current needed by the pi (4A or more, I guess) but not about the DAC. If it uses less than 1A max, how about an LT1115 based supply using a 6.3VAC 2A transformer to make about 8VDC raw supply, then regulate that down to 5V? 3V dropped by the regulator delivering 1A current means 3W heat dissipated, so a reasonably heatsink should work well enough.

[HemiRick]

The Boss DAC draws .6A I read somewhere

[Listener]

Any idea how much maximum peak current an Allo Boss DAC draws? I see discussion about the current needed by the pi (4A or more, I guess) but not about the DAC. If it uses less than 1A max, how about an LT1115 based supply using a 6.3VAC 2A transformer to make about 8VDC raw supply, then regulate that down to 5V? 3V dropped by the regulator delivering 1A current means 3W heat dissipated, so a reasonably heatsink should work well enough.

Four amps seems like a good guess at peak current from my observations. I am currently using five amp power supplies from Jameco that seem to be doing fine.

One issue I don't see talked about much is heat. Three or four amps creates a lot of heat to dissipate. I believe that Pi's designers understood that and have installed on-board cpu throttling that cuts in when cpu temps get too high. So good quality heat syncs glued to the cpu seem like an essential. There are a variety of thermal adhesives available for this purpose. And for those that like to play, maybe even a tiny fan.

Best,

     John