Raspberry Pi Forums

I use the Pi as a audioserver with Volumio. I use the IQaudIO DAC extension. I suspect the sound quality can be significantly improved if I use a good power supply. I suspect I also get less malfunction from the Pi itself.

Anyone know a good power supply for the Pi?

http://shop.pimoroni.com/products/pihub
but any decent powered HUB will do

Does anyone know if a switching power supply is decoupled from the mains? Can I plug it across my netfilter?

Which power supply type is better: Switching or regulated (non-switching)?

Yes a switch mode PSU is isolated from AC mains for safety reasons.

Better in what sense? Switchers tend to be generate more electrical noise than linears.

drgeoff wrote:Better in what sense? Switchers tend to be generate more electrical noise than linears.

Exactly! That is wat I thought! I found a USB hub with linear power supply lingering around at my home and hooked it up with the Pi! It seems that the sound quality of my DAC has improved! Linear power supplies seem to have vanished from the commercial earth or someting...

Placebo effect?

Try taking a green felt tip pen and colouring the label on the PSU. That will attract the nasty sounding red and blue electrons and stop them getting out to your DAC.

drgeoff wrote:Yes a switch mode PSU is isolated from AC mains for safety reasons.

Is that really true? I noticed that in schematics that Google brings up there is no tranformer in most cases!

No! That would cause deaths! So which schematics are these?
Perhaps you are referring to switching DC/DC converters that are powered with 12V, already converted from mains by a mains to 12V transformer, or from a 12V battery, thats not a switched mode mains powered PSU as most "charger" type PSU's are.

Although with some unsafe "going up in smoke Chinese junk" adapters, the whole of the mains "isolation" is sometimes just one layer of cellotape! Deadly!

Indeed a purely linear power supply will be much less noisy than a switching power supply, and so most audio equipment tries to avoid using switchers.

Also, hopefully the used transformer will be well isolated, to keep capacitive coupling of the windings to a minimum to keep mains EMC noise signals out!

the disadvantage is that analog power supplies are less efficient, and so produce a lot of heat!

For real HiFi and low noise a small 12 V lead acid battery is probably the best and easiest to use. The inconvenience is that you will need to recharge the battery and monitor its charge state or the voltage. This power source will also remove any possible ground loops from your circuit.