Linear PSU - do they matter?

(Paul Butler) #1

I have put this question in Tinkering as i’m not sure where else it should go. I have an RPI3 running roonbridge to an AQ dragonfly black and am happy with the sound, but like many of us I cant stop tinkering…

I have now bought a linear PSU to power the Pi. Its on order and is several weeks away, and i’m already thinking I may be suffering from advanced audiophilia. Do these really make a difference ?

I should state that my Pi (for domestic acceptance reasons) resides in an area where there are lots of other electrical devices generating noise and currently runs from a standard pi power unit plugged into a power board

(Mr Fix It ) #2

Can’t recall whee I got the link for this but some interesting stuff

(Paul Butler) #3

Oh dear - perhaps I am finally disappearing up my own output !!

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#4

Interestingly, his conclusions are the same as made by an EE friend of mind that has designed and built a variety of (locally) sought after audio components incl. power amps, HPA’s and DAC.

(Mr Fix It ) #5

That said I don’t think it does any harm to use a LMS instead of a SMPS. In fact it may be better for other equipment in the room or on the circuits.

Personally I like to use us a LMS where it’s needed to get 2 or more voltages or where a self contained unit with electronics is preferred. I also don’t trust a lot of these MIC made supplies.

#6

Now we just need to wait for the not everything that matters can be measured brigade to chime in.

2 Likes
(Robert ) #7

New avatar :grinning:

(Paul Butler) #8

I think l will firmly remain in the “won’t make much difference but can’t do any harm” camp. It’s in Tinkering for a reason ! All I need is a levitation device for the Pi…

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(Rene Bouwmeester) #9

Peace of mind… Priceless. :slight_smile:

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(Andrew Cox) #10

I’m not sure about the Pi, but when I upgraded from an iFi to the LPS-1 UltraCap PS with the microRendu there was a definite and appreciable improvement in dynamics. It wasn’t just me noticing it either, one of my tube amps (Manley Snappers) has always been a bit over sensitive and it started blowing B+ fuses on a regular basis.

(Peter Wright) #11

I found that a Pi with a HiFiBerry DAC sounded much better with a battery power supply, the same Pi with a USB DAC having good power regulation did not change in sound with the same testing.

(Rene Bouwmeester) #12

My main Pi is connected to my system via Digital Coax. Even though it has a nice LPSU, the one thing I’m sure of is that I’ll not be able to identify it in any blind test.

I think Peter is on a good track though – it may matter more in situations where the Pi is doing the D/A conversion, as opposed to where the signal stays within the digital domain (SPDIF/USB).

(Paul Butler) #13

Thanks for all the advice. Its coming, I shall plug it in and revel in the glow of confirmation bias with that nagging feeling that the Roonies told me so !

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#14

Power supplies are certainly all the rage now, in fact i’m pretty sure the Uptone LPS-1 will end up on Oprah’s “favorite things” list lol.
Having said that, i’m in the camp that they can make a difference based on my experience with the MicroRendu and unfortunately now I’m wanting to ‘re-power’ other components like my router, modem and Mac Mini…where does it stop!

#15

Thanks for that, I needed a laugh :joy:

(Paul Butler) #16

Unfortunately my LPS is being delivered by a combination of donkeys and tricycles - 4 weeks to wait for the veil to be lifted

#17

did they do the assembly too :grinning:

(Paul Butler) #18

I do hope so

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#19

Hi guys

I’ve just upgraded the power supply to my Hifiberry Dac+ Pro.

Like Hans beekhuyzen found in his review of the Dac+ Pro, I found that adding higher quality power supplies to the Pi3’s microUSB port didn’t make a big difference.

But when I bypassed the pi3’s internal SMPS and powered the Dac+ Pro directly with an iFi iPower 5V, things improved. I’ve just tested with a 5V battery supply and things now really got interesting in my system.

The Pi’s internal SMPS is what may limit the effects of better power supplies. I’m not really confident with DIY stuff. Luckily for upgrading rhe Dac+ Pro I didn’t need to solder anything but I will need to soldee to upgrade my Digi+ Pro’s.

I should have the required solder and tools by Friday hopefully, so I can do the upgrades on the weekend. Fingers crossed I don’t destroy the boards or the house lol :joy:

Btw with the sonicOrbiter SE, which is based on the cubox-i, one of the things they did is take out the internal SMPS and allow users to power everything externally with cleaner 5V DC power. So no soldering required but it’s a little pricier than the Digi+ Pro and Pi 3 combination. There are other advantages that unit has too, like very good software.

(Le Baron d'Merde) #20

There is a clear problem on that experiment!

I do not know any of the devices tested but I do think all of them are just ordinary motherboards, what means they are full of the usual SMPS regulators you will find in all ordinary motherboards, and not the “ultralow noise ones”, you find on SOtM products for instance, neither linear ones.

That said the use of linear power supply would make little to no difference, it is expected.

It make me remember another faulty experiment I saw years ago but about balanced mains.

Making the story shot, and assuming they correctly built and installed the transformer on that recording studio, they did all the test they wanted, and then made their statement about balanced power being useless.

The only problem with that experiment rely on the fact they did not swap their ordinary un-shielded studio structural wire to shielded ones (what indeed they should be using from the beginning).

So, does not matter if you have clean (or even god blessed) mains at the entrance of your house if you do not protect it until the point you need it. EMI/RFI everywhere theses days.