Less noise and ripple using a powerbank?

Does it make sense to use a powerbank instead the official and recommended micro USB power supply from Raspberry Pi to avoid/prevent ripple and noise in power alimentation?

Does a powerbank make less ripple and noise than a normal psu?

in theory yes. there are even high-end brands, delivering battery packs for their streaming solution, but…

It comes with some disadvantages.

  • Battery packs will be drawn empty rapidly, as the rPi really likes 2A+
  • You can solve this by using a battery-pack that has a feed through (when empty it will forward the charging adapter’s output)
  • To avoid issues when the feed through is activated, you need a low noise PSU
  • As you already need a low noise PSU, use that PSU and forget the battery pack :slight_smile:
2 Likes

My RasPi 3 Model B Rev 1.2 with Volumio 3.179 with HifiBerry Digi+ Pro 2017 connected by WLAN 2,4GHz draws 0,3A. Fix! My powerbank has 20’000mAh.

My goal is to have no galvanic leading connections from Raspi to outside.

He it’s your hardware, I just give you the information. What you do with it, is fully up to you.
If your battery-pack will do the job, I can’t tell.

  • A battery-pack has electronics at the output, to avoid burn-outs when shorted or overdrawn. This might introduce ripples or spikes
  • You need to check the max current, as 20000mAh, doesn’t mean it can deliver 20A for an hour. But in the best case 4.8 A for 1 hour. So theoretical you’re good for 9-10 hours.
  • And make sure you have something in place, to avoid unwanted shutdowns when the battery is drained. (might corrupt your SD)

You won’t get a lower noise, because the 5V are generated from a switching boost or buck converter (depending on the number of battery cells)

To get a lower noise, the HAT or the USB DAC should be designed with a proper low-noise LDO and proper filtering to power the analog part of the circuit. The IC used as a DAC should also have good power supply ripple rejection, to avoid transferring most of the noise from the power supply to the audio output

1 Like

I recommend this power supply. It’s very low noise and at a reasonable price.
I am very convinced of it!

https://www.allo.com/sparky-eu/nirvana-smps.html

No. Even less sense as the since you a re using a HifiBerry Digi+ Pro. My understanding is the Digi+ Pro is not a DAC.

you could also try the allo isolator.
there are two versions of.

https://www.allo.com/sparky-eu/isolator.html

https://www.allo.com/sparky/isolator-1-2.html

There are always threads on hi-fi forums, discussing the benefits of using ‘improved’ power supplies, where people report hearing massive differences for the better.
In theory it makes good sense to feed a DAC with clean power.
I’ve powered my 5v DAC with ‘dirty’ USB, Switched-mode, Linear and battery supplies…and heard no difference.
Maybe I wasn’t listening hard enough, but as far as I’m concerned, if you need to listen that hard for a difference, then that difference is not worth worrying about.

Have a look at famous company Mutec Berlin what they do to have best signal quality
Mutec
and most precise master clocks. This is not just for fun.

I have a Mutec MC-1.1+
MC-1.1+
I feed with the output of HiFiBerry Digi+ Pro over BNC, Coaxcable RG U59 to the input AES3id of Mutec 1.1+ and then to the DAC. With the signal improvement and stabilization of the MC-1.1+ it sounds more precisely than going directly to the DAC.

Perhaps noise and ripple etc. from bad PSU may also deterior, disturb/distort clocking (digital domain) and add jitter so.

1 Like

You are unlikely to hear or measure any difference between your current 5v supply and a specialist linear one.

2 Likes

Hi, i am using a linear power supply named Sigma11 and since i have installed it the sound have changed signifficantly, more detailed sound, more analogic to say… If anyone have the skill to build it i recommande it.
https://www.amb.org/audio/sigma11/

I’d bet money that there would be some measurable difference.
But I’d bet more money that most people would not hear a difference - and probably no people in a blind test.

2 Likes

Power supplies make difference. I have different supplies on my implementations, all linear, so no switching bs.
One for the PI itsself, another for the screen and a few for the different sections of the dac and of course one for the clock.
Batteries do well here as long you remember to bypass them with capacitors. Chemical reaction is also creating noise.

A powerbank typically has 3.7 volt lithium cells, so they also contain electronics to increase the voltage to 5 volt. That means that the output power could be ‘dirty’ with AC and HF noise. So even in theory, no advantage at all compared to a regular mains-based power supply.

Note also that many modern ‘audiophile grade’ equipement already contains electronics that ‘cleans up’ power drawn from the external souce. Hence you don’t hear a difference at all.

Even though it’s definitively possible that there is a difference with high quality and tuned power supplies, people claiming HUGE differences are imho simply full of BS. They are welcome at my place any time for a double blind test, to be recorded on video and plublished on Youtube.

Euh, then we are not going to play the old 8 track, cassette tape or band recorders, looking at your name. As then indeed you’ll not notice the difference. :rofl:

(put in some links for all the youngsters :slight_smile: )

1 Like

lots of people think cassette is a shitty medium, until they have heard a good cassette deck, and realize they have been wasting time on digital all those years. Only vinyl and R2R surpass cassette in good vibes.

But of course a whole generation grew up in the believe that cassette sounds shit. There is even a trend nowadays called Lo-Fi that processes music with plugins that are supposed to make music sound ‘cassette’.

A few years ago I sold a Nakamichi to a musician who wanted a deck to make his recording ‘dirty’. I told him the Nak would probably not suit his purposed, and gave him a demonstration, and he couldn’t hear the difference over speakers between the deck and the CD. A few months later I contacted him asking about his experiences. He said the Nak didn’t work out, as it was too good. he bought a cheap Philips to do the job.

The last one I’ve had was the NAD 6300 monitor series and it sounded good. However I do favor the digital age.

going a bit off topic - my favorite tape deck these days has been a Marantz SD6000dbx with very warm dynamics - i even recorded my first CDs to TDK Metal type tapes to get a “subjective” better sound.

My opinion is - low noise PSUs can be also realized with really good switching supplies - but linear is making things a bit easier at some point to achive good results - if going to batteries - use LiFePo - these do have the lowest noise caused by chemical reactions.

However - first of all - take care of having really good speakers and amps, place these well in your room and then think about the PSU stuff :wink:

Best Regards
Josef

Take 2 in series and regulate the 7.4V down to 5V . But yes - stock models will step up from 3.7V to 5V by unknown technologies :slight_smile:

1 Like