Measurements and conclusion
Contents
We subjected the LHY LPS-25 to a few measurements. First, we measured the stability of the power supply on a Rigol Electronic Load. Then we looked at how much noise the LHY “throws” to the mains and how clean the DC output is. We did this with a Tekbox LISN, Picoscope 5000-series, a variable resistor and a splitter for common mode and differential mode. Finally, we looked at how the LHY affects jitter when connected to a switch. Also on the Volumio itself. We measured that with an Aeroflex 5000-series, our RF shielded box, an Axtal reference oscillator and an active probe.
Stability
The 12-volt version of the LHY LPS-25 performs extremely well. We see very stable and predictable behavior. The voltage drop is minimal; even above 25 watts. In short: neat!
The 5-volt version also performs downright nicely. We loaded it somewhat heavily in this test, to see what the power supply does if we were to load up to 5 Amps. Up to 3.5A it does fine; after that it collapses. We get up to 17 watts stable.
Noise
Noise to the mains is downright neatly under control. In fact, we just don’t see anything; this power supply is clean. On the DC side we also see neat values, although we clearly see more and somewhat higher noise than with the Plixir we tested earlier. All value for money, shall we say: the Plixir costs more than three times as much. So it is just as well that it performs better here.
Remarkably, the 12-volt has more noise on the DC output than the 5-volt version. Perhaps this is due to the regulator having to do a bit more?
Jitter
Looking at what this power supply does in practice, we immediately see the effect of a better power supply: the LHY reduces jitter on the Volumio Primo’s main crystal. Both if you use it on a connected network switch, and at the streamer itself (screenshot follows as soon as possible; it was not saved properly). By now we are familiar with this effect; so we are not surprised. However, it is still nice to see that a power supply has an immediate impact.
Where can I find this exact product? When I try look for it I can only find a much cheaper same looking version on AliExpress and on their own site for $140 I can’t find this thing being sold anywhere in the €289 range. If it wasn’t for the price difference I would assume this is the exact one you guys tested here, but is it? https://store.lhy-audio.com/products/lps-25-25w-audio-grade-ultra-low-noise-linear-power-supply?variant=45222392594605 (Thanks in advance, great work, you guys got me started with this network-switch PSU mania :D)
Oh I missed the Boelsz link. Well in that case… same question applies, are they really selling that exact product for double the price…? The Boelsz version is listed heavier, is it a modded version or something like that?
We don’t know, except there are many clones / forgeries made of LHY products. Furthermore, there’s this thing called VAT, Import taxes and shipment costs, so it is not a like for like comparison price wise..
Wondering how the LHY 25 would compare to the LHY 50, then the 50 to the much pricier one here. in this control scenario. I’ve got an LHY 50 powering a Volumio Rivo to really great effect.
I recently purchased two LHY PSUs, a 24v for a NAD phono-preamp and a 12v for a Suca U8 preamp/tube buffer. I haven’t listened to the 24v one yet. The 12v one didn’t fix the flaws in the Suca U8 which messes up the soundstage in my system. I will sell the U8 but keep the LHY as I am sure I will find a use for it in the future.
Nice! Yeah… Keep it. You will always find a use for it.
I have found a use for the 12v LHY, I just ordered a Shanling CR60 CD transport that runs off 12v but does not include a power supply.
I also have a third LHY linear power supply – LPS-A8 for my Eversolo DMP-A8. It is a drop in replacement PSU board. The Eversolo has two PSU, a linear PSU for the analogue section and a switch-mode for the digital section. The LPS-A8 has two linear PSU. I have been using it for around six months and I believe it sounds better once it burnt in. Bass seems to have more weight and high frequencies are slightly smoother. The only downside is the LPS-A8 has a slight mechanical hum from one of it’s toroidal transformers. It isn’t coming through the speakers. I measured it at 3db right next to the unit so is inaudible from my listening position.
I have one of these 5V LPS powering a switch and yes, black electric tape is your friend. Its waaaay too bright!
Yeah it is. It should be dimmable.