Cheap and Good DC Power Supplies

Pic shows LPS, but even in SM, smoothing ripples and regulation is basically the same.

Letter from Shenzhen (23-1): Cheap DC Power Supplies from Taobao
HiFi Bascis (XV): Power Supply - The Hope, The Fuss, The Expense, The Futility

Happy Year of the Rabbit!

Editor: Not long ago, around the time of 11.11, I wrote my first Taobao article in Chinese mostly for my HK readers, because the stuff are not available outside of the region. I liked the response and comments and resolved to write about more of my purchases. Most shall be in English for other readers in the West to consider, as some of the items may be found on Aliexpress, Ebay etc. I shall not search myself, as it’s hard work enough writing the article. I shall provide a Taobao link, which will have many pictures of the item. You’re on your own from there.

It's Lunar New Year, and I wish everyone well! In a few hours it shall be Year of the Rabbit. All the Best. I have buried a few risque pics worthwhile of Hugh Heffner at the very bottom.

This article nominally is to introduce the 3 DC Power Supplies (PS) I bought from Taobao (TB), but I shall take this opportunity to write about my beliefs in PS in general (and hence this is a HiFi Basics article), though they are likely to fly in the face of many “objectivists” (especially DIYers and those obsessed with measurements).

I shall start with my “Basics”, that is my Beliefs. It’d be a little long. Those who just want to browse the 3 PSs I use now can just skip this section.

HIFI BASICS: Power Supply

• How much does the PS influence the sound? More than most people think. There are many aspects to the PS, and every one influences the sound. Component Quality Take the most simplistic scenario, vintage tube electronics have simple PS, but seasoned aficionados know that the tube rectifier has huge, even profound, influences on the sound, more than the driver and output tubes. If you have ever heard the WE 274 (B or A), you would know what I mean (Currently, a humble Tung-Sol 80 tube rectifier, a tube derived from the formidable WE 274A; ST, engraved) is producing astonishing result in my APPLause 300B amp). But we would not want to over-state this. The rest of the PS circuit and the audio section of the gear the PS is used for are important too. Mind you, the rectifier is important in solid state too. That’s just a single component. And then there are Diodes, Chokes and various Capacitors and others. These components can range from a few cents to hundreds of dollars. Each has its own sound and pricier doesn’t always equate to better. I have heard too many expensive DIY PSs stuffed with deluxe components do a terrible job. Design and Regulation Over 20 years ago, I participated in several DIY Meets where the auteurs compared their works. There were many based on the simple Marantz 7 circuit, which is solid state (selenium) rectified without much regulation. Some would add a lot of regulation. Others changed it to tube rectification. Despite the additional components and circuitry, almost all of them did not sound balanced and not as good to my ears as my simple M7 replica. Mind you, M7, even the real thing, is by no means a perfect preamp; it simply cannot deliver big dynamics. Preamps with iron control and impressive dynamics were not to arrive till the era of ARC, CJ and the likes. Take ARC, their earlier preamps can be regarded as highly tweaked M7-like circuits, with much beefier and regulated PSs. As with the rest of the circuit, a good ear helps, but the PS happens to be usually the section the builder/user pays the least time evaluating the sound. Bigger and Better Current Delivery This usually happens in Solid State gear. Naim and Cyrus were among the earlier brands who actually sell PSs as an upgrade path, and the PS can cost just as much or even more than the amp. The addition of the PS increases the power delivery. But is bigger always better? Not always. Of course, if your loudspeaker is current hungry, it will help greatly. But if yours happen to be quite efficient, pushing the amplifying device harder may actually be counter productive. The harder the device is used, the more distortion arises. With a Digital Amp, like Aiyima T9, one can use 18-30V. In my case, I I thought the 19V generic computer PS sounds better than another generic 24V one (to use it as preamp, one can supply just 12V). Also, imho the bigger the power supply, the more likely the deader the sound. Monoblocks and Dual-Mono High End manufacturers have ingrained the audiophile into thinking that monoblocks are better than stereo. This is not true in many instances, let alone being gospel, and has never been. A vintage example is McIntosh - the MC40 monoblocks and the stereo MC240 are basically the same, but the stereo MC240 sounds significantly better. For the 47 Lab Gaincard, using just 1 Power Humpty sounds better than using 2. One wonders if the single PS in these cases enable more synchronicity in the 2 channels.

• What’s the limit of what the PS can do? Simple, my dear Watson. Whatever the gear, if it’s just ordinary stuff, there is only very little a better PS can do. And by ordinary stuff, I mean the majority of so-called hifi offerings out there, including megabucks stuff. The problem is, the majority of people who want to upgrade their PSs believe too unduly in their gear, usually at the urging of netizens who promise nirvana (and transforming things into “giant killers’). Most would be disappointed in the long run, and would sell the gear while throwing in the “upgraded” PS.

• What benefits the most from a better PS? I’d say, first, the cheap (but good) stuff, like a digital amp with a wall-wart. At the highest end, this likely holds true too. A WE PS is definitely going to be better than a DIY effort, no matter how expensive the modern components used. The BIG problem is the middle 90%, where you can perhaps hear some changes, but in most cases they won’t change the overall assessment of the gear. Expensive upgraded PS is now a commonly offered path for “upgrade” for many audio brands, but usually after you fork out the dollars you still cannot escape the confines of the product and the greatest flaws of the design will not be improved. In most cases, it would be better for you to forge a new path and change gear. There is only so much the PS can do.

• Linear PS (LPS) vs Switch-Mode or Switching PS (SMPS) For the longest time, there were only LPS. With the advent of digital, SMPS came to the fore. At first, it was regarded as just noisy and nothing but interference, used only in computing and the likes but, as technology matured and geek gear started to shrink in favor of smaller ones, audio people (at least the low end) started to take notice. At first, only the digital DAC and Amp people (like the Chinese) use SMPS. But then, SMPS started to make it big, even in high-end manufacturers. Time flies, and it has been 25 years since Nagra unveiled their first home-use audio product, the iconic PL-P (which I still have and have high regards for). It sports a separate SMPS! Today, many European high end manufacturers use SMPS. Witness Swiss Soulution (their GBP 20K “entry level” 325/311 pre/power combo uses SMPS, and I’m pretty sure SMPS are also liberally used in their upper echelon products). It’s interesting to note that many European hi-end (witness another Swiss one, Goldmund) embrace digital technology and SMPS, much more than the US hi-end. Witness the advent of the T-amps and later ICE modules to hi-end gear. Perhaps it has to do with the more pan-European conviction of their green responsibility to the environment (US is despicable in this regard, as in many aspects of their world-view). Talking about skepticism of new technology, Surface Mount components have been ridiculed for a long time but I actually think they are very good. Again, Linn in the UK was among the first to use SM components in their products and they sounded quite decent and those were what converted me, decades ago. There is MUCH BS about short signal path in audio - what can be shorter than SM components? If you look at the tiny PCB of a Linn Linto or a humble Kolector, you will get the point. BTW, Linn also embraced SMPS, even in its phonoamps. As with SMPS, in the US, pretty much no hi-end pretenders would do this. If being green environmentally is left or progressive, US audio industry mostly remains in the far-right.

• Aftermarket Audiophile LPS Supplies are a dime a dozen. They range from very reasonably priced (as in the offerings below) to the ridiculous. Usually, the more expensive it is, the greater the hyperbole. As I implied above, no amount of PS upgrade can elevate a pedestrian offering (which is most stuff) to the transformative level, despite claims on the net to the opposite. There are probably more PS for flat-earth Naim people than anything else. It is reasonable to expect subtle but meaningful differences. Please don’t believe in a sustained Night and Day difference; in most cases you are likely in Scandanavia, where sunshine breakthroughs are possible but rare.

• SMPS Upgrade The 2 featured below are very cheap and yet surprisingly effective. These most definitely outperform the wall wart type SMPS that comes with your digital gear, be it DAC or Amp. These are not originally meant for audio applications, instead for industrial use, for repairmen and surveillance cameras etc. The difference between these and the wall-warts is that these are much better built and can deliver much more current. They are good for amps, but the difference made with a DAC is perhaps even more surprising (see below).

TAOBAO Offerings

https://m.tb.cn/h.UPPaQjS?tk=kSg0d5HlRWA

The first one I bought (branded Gophert) was an SMPS. There are many options and I picked 32V 5A max. Price now is RMB 231 (around USD 35). Tactile buttons are used for selection of voltage and current (as well as lock), which are adjusted (fine and coarse) with a knob. The build is excellent; the TB page claims excellent regulation and smoothing close to an LPS. Mind you, I picked it only because it is compact and looks better than its rivals. I had no idea whether the innumerable other ones are better or worse. The only thing I’m certain of is that it made a difference with my Aiyima T9, whether as an amp or as a preamp (written up here). For this article, I moved it into my reference tube system in my study, and used it with my DAC (see section below)

Then came 11.11 and I bought 2 more. Prices now are actually about the same!

 https://m.tb.cn/h.UOY51zT?tk=7jjZd5Hlw2s

This one is another SMPS (branded Wanptek), with somewhat different features but similar spec’s as the previous one. This is also a regulated unit. The back has a 110/220V selector so I’m pretty sure this one sells in the US. You can see from the pic that the innards are quite a bit more stuffed than the Gophert. There are many options and I again picked the cheapest 30V 5A max (GPS305D). Right now the price for my unit is RMB 148 (around USD 23). Its simple rotary dials are easier to use, but it doesn’t have voltage and current caps, nor lock (I have turned it on and off and it always stayed at the last setting - just don’t accidentally bump it up and down while it’s on, not a likely thing without a child around). Unlike the Gophert, the shell is perforated and there is a fan at the back. I used this for a long time in the main system in my study, where I used it to power my DC 5V 1-bit TDA-1305 DAC. Compared to the stock PS, the sound is immediately more graceful, transparent and subtle. This is amazing because the display indicates it is drawing a mere 0.11 A in use and less than half of that idle (so the fan never turned on). The front also sports a useful 5V USB DC output. You can use it to connect your 5V devices (say BT) or charge your phone. As my DAC is 5V, I did try this output (you’d need a USB B to correct-size DC plug cable, which I happened to have) but it doesn’t sound as good as the main output.

Gophert vs Wanptek For this article, the main recording I used is a recently re-issued old MHS recording of Haydn Piano trios (Musical Concept-Orpheus). The difference is subtle and they are more alike than different. The Gophert may be just very slightly smoother with the violin and a tiny bit more rhythmical; whereas the Wanptek seems to be a just little airier and relaxed, though possibly slightly grainy with the violin. I could use either in either of my 2 locations. They have different form factors - the Gophert is a horizontal slab (but you can easily have it vertical too) whereas the Wanptek is a vertical one, so aside from looks, I’d pick the one more suitable for your space. Also keep in mind that, at least locally, the Wanptek is “significantly” cheaper than the Gophert.

https://m.tb.cn/h.UPPZmbY?tk=icscd5HO51F

This one is an LPS, said to be modeled on Studer, offered by BRZ or Weiliang Audio (they are the same). Right now, 173 RMB (about USD 26). Unlike the SMPS ones, it has fixed output with limited current capacity. There is a cheaper 15W option and a slightly beefier 25W option. There is also a Talema Transformer option for a small premium. You have to specify the DC Voltage you need. Think of it as tailor made. I ordered a 12V one for a device, and it made an improvement but then, all of a sudden, I lost interest in the device and regretted my purchase. I then thought of converting my unit to 5V for my DAC. I noticed (see pics) on the PCB there are Hi, Med, and Low settings. I asked the seller, told them that I can solder and would not hold them responsible, and they very helpfully told me how to convert it (see pics). It is a very cramped space down there and the low setting through-holes are close to a resistor. First, I sucked out whatever solder there was, then I had a hard time bridging the 2 LO through holes though I achieved my goal finally. After connecting the through holes in proper fashion, one then has to adjust the adjustable resistor to get to the correct DCV output (measured by a multimeter; for Aiyima and the vast majority of modern devices, the center is +, so insert the red probe of the multimeter into the female DC plug and put the black probe on the outer shell). Note that the adjustable resistor has only a small and finite range. When mine was still 12V, I did try and I could only go down to around 7V, which was why I had to perform the jumper modification. I also bought a 7V one for ELO, and that one cannot go down to 5V either! The price is more than reasonable for an LPS and you may as well buy another one if the need should arise.

Click pic to enlarge. Upper L near the power inlet, notice the Hi Med Lo through holes. The LO are bridged for my 5V application. Notice the sand colored adjustable resistor at the upper left corner of the power trans.

Through the same DAC TDA-1305 DAC, the sound was different enough from the SMPS. Amazingly different. Both SMPS, when first connected to the gear (Aiyima T9 and DAC, respectively) gave a more spacious, relaxed and refined sound, with a little more details. Not quite so with the LPS. Replacing the Wanptek on the DAC, I instantly noticed a tightening of the proceedings. Certain instruments came to the fore, others became more indistinct; rhythm seemed more upfront, even insistent at times. This recently re-issued long oop print album is just fascinating. Huyette Drefus’s fortepiano to me is more correct in timber with the SMPS - the LPS sounding a little too much like the modern piano. Yet Eduard Melkus’ violin, although a little subdued, had more texture whereas in comparison the Wanptek SMPS was a little grainy, even if airier (the Gophert is a little closer to the LPS in a way). The cello is rather subdued in this recording anyway to be a factor. So, this reinforces my impression that the SMPS has more air, likely due to high frequency performance, and the LPS likely has more solid mids and bass. I have gone back and forth, with my fixed reference system, and I’m still not sure which I prefer. The only thing I’m sure is that each likely offers something that the other doesn’t quite.

A word about this particular LPS. It is NOT for an amp, or high-powered devices. It’s output is only 15 or 25 watts. One can calculate one’s need. Watt (P) = IV where I is current (in A) and V voltage. Say, your device is DC 7V (ELO’s Elekit TU-875), the 15 watt option will give about 2A, the 25 watt version closer to 4A. But, if your amp works on 24V, even if you get the 25 watt version, you won’t have much more than 1 A of current. Not enough headroom to play safely at a decent volume, so only for front-end devices. But for those looking to power DAC’s, many headphone amps, BT devices and digital preamps, this looks like a cheap and excellent option for an LPS.

Conclusions and Thoughts

• Adjustable and Regulated SMPS These units that can deliver higher currents that are seriously good, much better than the stock wall wart PS that come with your gear. This is as much true for a bigger 24V (or 30V) slab for your digital amp as the tiny 12V one for your preamp or BT, or the 5V one for your DAC. If you own such devices, just get one, for very little money - guaranteed satisfaction. IMHO SMPS has entered maturity, used often in high-end and does not deserve its previous “bad rep”. In fact, when a manufacturer says, “we believe in tradition, shortest signal path, highest quality component, attention to details...” (sounds familiar?) start to worry, especially if their stuff is expensive!

• Regulated LPS The LPS I recommend here is ridiculously cheap for what it offers. If you have a front-end device, DAC, BT, preamp or a headphone amp, seriously consider this. Keep in mind it only has a fixed DCV and has limited current ability. Not flexible, so only consider it for a FAVORITE device that is likely to be around as you go along. At this kind of price, there is no reason not to try. Personally, for high priced aftermarket LPS, I’d refrain for reason mentioned earlier.

• SMPS vs LPS I see strength in both. At the price of the offerings here, there is no reason not to try both if just to get a feeling. Personally, I lean towards SMPS - no fuss, flexible. I shall continue to use the LPS for my DAC (there’s no other use for it now, at 5V), and the Wanptek is free to do other duties. In the LR, the Gophert shall serve the Aiyima T9 on the low shelf. But if I have to shuffle them, I’d not have any reservations.

• Connectivity After all this writing, I’m in no mood to write in detail (or provide links) on this. Suffice to say, you NEED to know the spec of the DC Plug of your gear. The most common is the 5.5*2.5 where 5.5 and 2.5 mean the outer and inner diameter of the plug in mm. The next most common is 5.5*2.1, and these 2 are sometimes interchangeable (but not always; Aiyima use 5.5*2.5 and will NOT take 5.5*2.1, but my DAC takes both), Most of these PSs come with some kind of cable, but they are often not what you think. The LPS above is made for audiophiles and therefore comes with a proper DC cable, 5.5*2.1 at either end, as is the convention. If you need a 5.5*2.5 or whatever other sizes, you’ll need to buy a set of DC Plug ADAPTORS, which by convention takes in a 5.5*2.1 plug (most will also take in 5.5*2.5) and outputs whatever other size. In case you need to measure the plug, I’ll suggest an accurate caliper. For the SMPS, they are not primarily intended for audiophiles and hence come with cables for testing purposes: the bare wire (or banana) end is for connection to the PS, the other end is usually crocodile clips. You’d need to buy an extra cable that is bare wire at one end and DC plug (5.5*2.1 to be universally used with an adaptor kit, as stated above) at the other. Of course, you can also DIY a cable, as DC plugs of all spec’s are available. Study the pics below carefully. WARNING: Study this yourself. As I have provided the basic info I’ll NOT entertain any further question on this subject. U have to source what you need yourself.

L. for SMPS, bare wire to DC Plug (5.5*2.1, here connecting with a 5.5*2.5)

Center, bank of adaptors.

Right, the cables that often come with SMPS, with crocodile tips for testing purposes.

Bottom, Cable that came with LPS, DC plug (5.5*2.1) at either end) 

My System. Beneath the PSs,black DAC and Reisong transformers;

beneath, Preamp; to the right, Schumann generator.

Innards of the Gophert.

Innards of the Wanptek

Taiwanese JKF Girls' Rabbit Year Greetings