I’m really not sold on LPS. Whether a power supply affects your endpoint/DAC boils down to your DAC.
I have 2 X RPi 4Bs both powered by PoE hats (the orientation of the USB/Ethernet and power input of the RPi sucks (why couldn’t they all be on one end?) so I wanted only one cable. One feeds a Sanskrit 10th V2 DAC, the other a Topping DX7 Pro DAC. When fed from my Dell X1052P switch, the SMSL exhibited hum and noise when playing silence with the volume on the Amp at maximum. The DX7 Pro did not. I switched the SMSL over to my Dell PowerConnect 5548P switch and it was silent. I tried both DACs with both RPis on both switches and the result was the same (Both DACs connected via USB) - the SMSL was noisy when connected to the X1052P.
The point is that the Dell X1052P has much noisier PoE than the 5548P. The DX7 Pro was immune to the noise, the SMSL was not. Not entirely surprising given the price differential between them.
In short, if your DAC is susceptible to noise from your streamer, don’t add a LPS to your streamer. Buy a better DAC - and no, not some fancy overhyped/overpriced snake-oil DAC, but one which is designed well and measures well in relation to noise and power supply noise rejection.
If a LPS improves a component, the component doesn’t have very good PSRR ( Power Supply Rejection Ratio), i.e. it could be better designed. Don’t compensate for poor design by adding expensive accessories, buy something that’s well designed in the first place.
My SMSL is staying for now; it’s in my secondary (office) system, but ultimately it’ll be replaced by a better DAC.
One more thing, which has been mentioned in the past - many electronic devices have different internal power supply rails, e.g. 12V, 5V, 3.3V, 1.5V, 1.35V etc. To derive those from the main PSU, they have internal SMPS. Adding an external LPS is pretty pointless if it’s in turn feeding another SMPS.
Indeed. Where it might make sense is if you’re powering a Class A amplifier, something that lives in the analog domain. Of course, a good one should do its own power conditioning. But for digital devices, it’s pretty much pointless, as you say.
I’m really sorry, but that statement couldn’t be further from the truth:
See the second picture. The Rendu incorporates the LTM4625, a step-down switching regulator operating at 1MHz:
With regard to adding a LPS to the Rendu, Amir had this to say:
“Of note, no matter how clean your input power supply is, the switchmode “post regulator” above will make it “dirty” again, assuming everyone agrees that switching regulators are dirtier than Linear Power Supplies. In that sense, I don’t see the focus on using different external power supplies here. Indeed in my testing with two different linear power supplies, there was no difference in performance.”
Regardless of one’s personal opinion of ASR, what cannot be disputed is that Amir’s reviews and teardowns are scientific and objective.
I feel it might be a little dismissive to call linear power ‘a fad’.
Sure you can get well measured SMPS, but this doesn’t mean LPS’s can’t provide an improvement when directly compared to OEM or after market SMPS technology.
With the popularity of measurement based reviews, consumers can now ‘more’ easily seek out scientific performance data for devices. Sbooster and Super Farad for instance both measure exceptionally well, performing with lower noise than many SMPS’s. Like with all hardware, there will be both good and bad implementations. So its important to try, before making comment or forming judgement.
IME, moving from an ifi x power 5v SMPS to my Gieseler Audio KW dual LPS supply made a noticeable subtle improvement on my Raspberry Pi and Motu MK5 lite dac. System tonality absolutely improved, becoming more relaxed and natural.
Likewise there was an improvement moving from the OEM supplies and the ifi power X.
Typically, I use measurements (objective data) to point me in the right direction, and then my ears (subjective experience) to make a final judgement call if a piece of hardware stays in my system. I like data, but I trust my ears to make the final call.
For instance, I have used ASR measurements to help guide many purchases.
Including, Purifi based amplifiers (So no, I’m not against switching technology), an RME Adi 2 dac fs (Used an OEM Meanwell SMPS), and a Motu MK5 DAC lite.
Yes it’s a fad. Point being, many devices have on board regulation in the form of a switch mode dc to dc convertor, accepting a wide range of input voltage - whether you feed this internal power supply with an external smps or lpsu is largely irrelevant, the electrons don’t care. Two things will make your expensive linear psu sound better: possibly the ground path (not a given), and your brain. IMO
And that’s the great thing about this hobby, we are all free to experiment with different equipment and configurations in search of audio nirvana. A forum is a place to exchange ideas and discuss things