Power Supply Discussion: Linear, SMPS, Battery. Allo Shanti LPS Review

REASON

Power supply discussions seem to generate a lot of strong opinions, and since I just carried out some concentrated listening of various power supplies, I thought I would jot down my impressions, a lot of it for my own record, thus as succinct as possible.

SETTING

All power supplies mentioned are compared on Chord Qutest DAC and were all plugged into modified Liebert on-line, double-conversion power generator. To minimize variables and to maximize minute differences, all supplies were compared on the same rig comprising of Schiit Jotunheim R amplifier powering Raal SR1a ribbon headphones by the way of Norne Silvergarde S3 pure silver headphone cable.

ALLO SHANTI LINEAR POWER SUPPLY

0827201234 by drjlo2, on Flickr

The thing I like about Allo Shanti is that despite what is obviously of serious build quality, its price is in the computer/IT realm not in the audiophile uber price realm. It annoys me when certain audiophile companies pretend like they are selling solid bricks of gold, similar to how medical supply companies quadruple prices for “medical grade” power plugs, etc. The fact Shanti sports the latest audiophile perks like supercaps on output and provide two outputs (5V/3A, 5V/1A) is a bonus.

In direct comparison to Chord’s stock SMPS (which actually sounds quite good) and Bakoon BPS-02 Lithium battery PS, Shanti differs by offering more density of texture and information. At first glance, I can see some people actually preferring the stock SMPS, which sounds “prettier.” In photography/video terms, SMPS is akin to turning up brightness half click and turning down contrast half click. This creates smoother yet airier sound that can be more forgiving of poor recordings while still bringing life and sparkle to music.

Shanti actually seems to pull together the sonic pixels into more dense balls, so the performers are less diffusely large/forward. Those who prefer large, forward, diffuse images (like from Magnepan speakers) may like the SMPS presentation more, especially with certain recordings that need that treatment. This density carries into bass as well. I’ve seen others mention that certain heavy-duty LPS’s, including some mentions of Shanti, produce much more bass than “puny” SMPS’s, which may or may not be the case depending on system. On this system, what Shanti does is produce more dense, solid bass, which can give the impression of “more” bass due to noticing its presence more. This is not night-and-day difference at all, and I consider SMPS bass perfectly great.

The puny stock Chord SMPS plugged into Teslaplex AC outlets.

0827201137 by drjlo2, on Flickr

The main thing that may keep the Shanti around is its better retrieval of low-level details from mediocre recordings. With recent, high-quality recordings, the system sounds perfectly faultless with SMPS; it wants for nothing IMO. Mind you, this is only possible due to numerous refinements and optimizations over the years, i.e. just the right cabling, power treatment, adapters, server, software, etc, etc. If I listened to great recordings all day, I do not need to use the Shanti or Bakoon battery supply. However, with good-but-not-great recordings from say 1990’s (good luck with 80’s recordings), Shanti pulls in just that last few percent more detail resolution, so the decent recordings become more insightful and enjoyable. One can hear a bit deeper into singer’s smacking lips or quick inhalation before belting out, just a small bit more of venue wall reflections and sound trails as trumpet notes fade.

THE BAD

At this price point, the only negative that bugs me is the attached DC cable. It is very thin and extremely long. I already know DC cables sound different by comparing and DIY’ing them, so at some point, I suspect I will mess with these. If better DC cables weren’t possible due to target price, then Allo should have at least provided DC jacks instead of permanently attaching them IMHO.

WHAT ABOUT BATTERIES?

IME, garden-variety laptop 5V battery supplies do not sound great. Along with cheap, poorly-designed linear power supplies, these battery supplies tend to place a veil over the music while overly smoothing things out. I get best sound quality by using batteries at their native voltage, in which case, clarity and life is preserved. Unfortunately, one can’t find native 5V Lithium batteries, so the next best thing is the Bakoon bps-02 Li battery supply (same unit here OEM JCAT).

ShantiBakoon by drjlo2, on Flickr

With a good Li battery supply like this, the entire presentation is different. Whether the difference is “better” or “preferable” is up to the individual’s tastes and system synergy. The background really does become more “inky black” like many reviewers out there report. Textures and details become sexily pure and liquid while instrumental and vocal tone become rich, deep, wide. I mean, who wouldn’t like THIS, one wonders. Many audiophiles can actually stop right here and not look back.

But since I am particularly particular, I have noted one tendency. Music is beautiful with noiseless background, but after long listening sessions, I do notice a sameness, a recognizable signature that slightly coats all genres. It’s slight and it’s a pleasant signature, but after a long session, I feel this signature lessens the excitement and anticipation of finding out what the next track would sound like, and a different artist next, etc.

Since I am not aware of native 5V batteries to compare to Bakoon, I cannot be sure if this tendency is due to the fact it still has internal voltage regulation or due to powering a device with both digital and analogue amplification circuitry. The times I can power a purely digital component with native battery, I do not hear this “sameness.” For example, I am powering SOtM USB soundcard and USB-spdif converter with 18650 batteries, and there is no downside here. In past, using 12V native batteries to power other pure digital components also did not result in any downside, either. Oh, well, I suppose this question is unanswerable at this time, other than to recommend that one should try native-voltage batteries on purely digital components if possible.

19733647013_232899f3e8_o by drjlo2, on Flickr

THE END
…to be continued.

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Sounds like those Maggies are in too small a room. And you’re too close.

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Touche…
I do love Maggies when set up correctly in correct room for the things they do right.

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I really tried to avoid doing this for 5V native battery power, but I will take one of the team and try 4x 1.2 V NiMH rechargeable batteries. I will double them up (8 batteries) for decent playtime and will need to manually change out 8 batteries every time they run low, but we ARE audiophiles.

AAcase by drjlo2, on Flickr

0828202047 by drjlo2, on Flickr

Nah.

Modern PVRs and LNR/LDOs give much better noise and ripple performance than batteries. And they don’t have a constantly changing noise/ripple profile over time.

Another benefit is that you don’t have to deal with the gymnastics of getting precisely the right voltage.

It always tickles me when I see people replacing good-quality external box-in PSUs with USB Power Banks and claiming massive improvements in sound. Particularly when those power banks invariably involve cheap buck/boost converters and/or low-end regulators (because USB power isn’t THAT tightly toleranced).

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No.

LDOs and even diodes (LEDs less so) produce ripple or noise. That ripple could be filtered out using tuned oscillators or by preloading the regulators. I am yet to see that in any audio device.


Having looked at tons of internal layouts of various devices, I can see it changing how a device sounds. The rest is personal preference, I guess?


Is that ad-hominem?

If that is, delete this account and associated data as per GDPR.

Yes.

Not all, to be sure, but you don’t need particularly exotic or expensive ones to beat a straight battery (or better still, single-cell) supply. Differences are easily and repeatably measurable.

Now, the differences get smaller when you’re dealing with constant load, single-cell, solutions with very low internal resistance. Still beatable though, and without heroic implementations.

If this wasn’t the case, we’d be using battery supplies in the most sensitive instrument designs. We don’t. They’re not quiet enough, nor stable enough, even forgetting about the relatively poor dynamic delivery capabilities, significant droop under load, and constantly changing noise and ripple performance.

(Not going to argue back and forth about it, either. Too many bad assumptions and misconceptions to work though - and I’m only doing that if I’m getting paid).

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Nope.

I’m just preemptively opting out of further discussion on it, on the basis that to make it a useful and meaningful, detailed, public discussion, even just overcoming the myriad bad assumptions and misconceptions that pervade the audio-world around power-supplies/sources is more work than I’m willing to put in (with references, models, math, physics, data-sheets and so on) on a hobby site/thread.

Poorly phrased, probably. But that’s it.

This is already over my head, but it is getting interesting. When I’ve thought about stable power supply batteries, I thought big old fashioned wet cells.

Upgraded the DC cable on Allo Shanti with VH Audio 18 AWG Unicrystal OCC copper wire in Airlok + Schurter DC plug.

0910200751 by drjlo2, on Flickr

0910200950 by drjlo2, on Flickr

Then I made a native 5V battery supply using rechargeable NiMH AA batteries, 2 groups of four in parallel. Fun times ahead…

0910200831 by drjlo2, on Flickr

What I have feared has come true. I truly did not want the AA batteries to sound best because who wants to change out 8 batteries manually every few hours?

Unfortunately, the native NiMH AA batteries sound significantly better than the Bakoon Li battery supply with internal regulation. That slight bit of warmth and pleasant richness has been burnt away, along with cloying sense of sameness. What is left is ultra clean background with crisp, fresh, resolute clarity and body. Nothing is blurry or murky, and although poor recordings are even easier to identify, their brittle, harsh, thin recording quality is communicated clearly while not exaggerated.

The good news is that Allo Shanti LPS, when upgraded with shorter, better-quality DC cable and fed from a good power cord from a good power regenerator, turns a few sonic corners toward the sonic signature of native batteries. The stock DC cable is found to darken and smooth out the sound a bit at the expense of clarity, but this signature actually improves tolerability of some brittle and thin rock/metal music. Future experimentation with different wires are planned, and I may end up installing a DC jack for easy cable swapping.

No rest for the wicked… (as I change eight AA batteries and two 18650 batteries for the system).

image
Perhaps there IS a one battery solution.

I am in no position to laugh…

0911201626 by drjlo2, on Flickr

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0912201035 by drjlo2, on Flickr

Some concentrated comparisons took place.

Audio server.

HDPLEX LPS vs. 12V Li Battery.

With stock DC cable and power cord, HDPLEX sounds less resolving and coarser than battery. However, after DIY’ing a DC cable until it sounded better, which meant starting wtih pure silver but later adding OCC copper to the concoction, and finding a specific sound signature with a particular power cord, the LPS now sounds in general ballpark of battery sound signature. Battery still sound a smidge purer, but LPS does have its own charm of tiny more vocal texture, close enough for me to use the LPS for the music server.

SOtM USB card and DXIO USB-spdif converter.

18650 Li battery vs. various LPS and SMPS in house.

Here, the 18650 battery was found to be irreplaceable in preserving the sparkling purity of sound. I’m not sure if it’s the 18650 battery type itself that’s the difference or the fact only two 18650 need to be used, resulting in a simple architecture. It could also be that SOtM and DXIO, for whatever reason, benefit more from battery power, being very small, pure-digital devices.

Chord Qutest DAC

AA NiMH battery vs. Allo Shanti LPS

This was the most crucial comparison, since changing 8 batteries every few hours would have been a real bummer. Perhaps this thought acted as a bias, but with stock DC cable and power cord, Allo Shanti had a significantly different sound signature than battery. Shanti was darker, smoother but less resolving than battery. After DIY’ing a better DC cable and also DIY’ing a particular power cord design that pushed the sound signature to a direction I wanted, the Shanti now moved towards the battery sound signature more, i.e. purer, sunnier, more resolving. Images now projected forward easier with more presence. Battery still sounds bit more “fresh” and pure, but Shanti actually seems to have a smidge more low bass kick, so I could settle down with Shanti.

Further Thoughts.

When everything was powered by battery, it was akin to having every light in the living room turned on. Everything was visible and plain as day with ample light bubbling up in every corner. After awhile, though, perhaps things were a bit too present and lit. It was certainly an awesome experience, but with time, the fully-tweaked LPS’s introduced just enough shadow and texture to appeal to the emotional side. For my setup and tastes, keeping 18650 batteries and the two LPS’s hit the balance I wanted, but obviously YMMV and I may change my mind at any time. :sweat_smile:

I’ve always been somewhat skeptical of the aftermarket power cords that plug into a wall socket, and somehow magically make things sound better, that last 1.5 or so meters of cord making a difference given the yards of Romex in the walls and the miles of utility company cable, transformers and toasted squirrels on the way to the power station. (put discussion of placebo effect here)

I do however, usually plug my audio - certainly my better components into APC UPS supplies that I also use for the computers. I also have, and occasionally use (though I have not tried listening tests) a 1200 watt Trip Lite line conditioner which is supposed to give 90 DB of noise reduction and 60 DB of noise reduction depending on the outlets. If my UPS is on vacation to get a new backup battery, or if I am moving things around, the Trip Lite is often used.

On my home stereo, most of the wall power goes into some sort of conditioner/noise reduction/surge protector box from Monster (montiors voltage and has pretty lights). I got that box when one of the audio chain stores went out of business - used for 10% of list.

I’m not planning on spending $90-$490 per cord to upgrade the last meters of power from the wall.

Will y’all please tell my how wrong I am about my approach, and if any of the stuff I use has any effect?

I’m not ego-involved in your replies, and my budget won’t let me make many changes. This is just sort of misplaced intellectual curiosity.

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I forget who said it first: that 1.5 m of power cord is not the Last 1.5 m of power chain from power company but First 1.5 m of RFI/EMI antenna of the component’s power supply.

In addition, I neglected to mention that all of the reportedly good sonics with LPS is only possible because they are all plugged into my (modded) Liebert double-conversion, on-line UPS. It’s a long discussion on its own, but when choosing a UPS/power conditioner for audio sound quality, look for the words “double-conversion” and “on-line,” which means the power is regenerated 100% of the time(not only when power is out) from the batteries onboard via AC-DC-AC double-conversion.

The placebo effect is a lot cheaper today, at only $20 to $50 for a superior look and feel:

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So, do you really think it’s Placebo as I and Steve Martin might?


See a couple of minutes in. This sketch may be where wooden headphones got their start.

I’m not sure I buy the antenna idea. While it sounds possible, I’ve had enough trouble getting antennas that were designed as antennas to perform satisfactorily. And they had to be attached to a particular location. Why would 1.5 meters of RF rejection be good? I know that there is math buried in this question. Wavelengths, and Frequencies, and Decibels, (oh my).

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