Making of Aiyima T9 Pro

Video: The Making of Aiyima T9 Pro

Update 3/29/23: The Video is now available on Youtube and also embedded here.

It's very entertaining, and I learned a lot about the manufacturing process. I helped a little with the translation of the subtitles.

What truly impressed me is that the care shown over the manufacturing and Quality Control. This kind of testing and quality control is likely as good as, or even better than, many so-called high-end manufacturers. Come to think of it, in many cases the latter cannot really be easily returned (the more expensive the more so), whereas a cheap Aiyima can be returned to Amazon even after an unreasonably long time, so it's in the interest of Aiyima to make sure there are no small incidences.

Enjoy!

Viard HD12 Luna Gris Orange Entreq Micro Kit Studer

Click Pics to enlarge.

Sometimes, Things just Happen, Part I
Letter from Hong Kong (23-1): ELO reaches new heights, Part I

Sometimes, things just happen, even following just a small change, intended or unintended. One thing I have learned is not to give up easily on one's ideal, whether at work, in photography, or chasing the Audio Nirvana.

My Ideal System
Over the last few years, I have been chasing my ideal hifi system. While at times I have felt I was getting close, other times I would feel I still had not achieved Level One. I have set my target that for me to achieve Level One, the system must let me settle down to enjoy music. It sounds easy, to demand my system to let me communicate with the musicians, allow me to understand the nuances of every note and what kind of emotions they are trying to convey. In a nutshell, the system must make me feel that the musicians playing through my setup are professional and skillful enough to be worth their payroll cheques!

Equipment that anchor my system That would be my Dynaudio Crafft, the Emerson Analog (I have re-iterated so many times that it is a gem for the price and for what it offers), the RJ45 ethernet cable HD12 from Viard (very smooth and musical). These stay constant. Following are the other players, first some brief updates to remind you of my system (below in shaded box), then some newer ones.

Aiyima A08 Pro I had before some high-powered amplifiers. While they were fast, had deep bass, good extension on highs etc etc, and could drive my Dynaudio Crafft to adrenaline raising level, they didn’t make me settle down. I know some of my acquaintances are laughing at me for using this little Class D amp, but I find it to have ample power for driving my speakers. Moreover, it does not sound edgy and piercing, though I still find it to lack the last bit of musicality. Enter the tube Elekit TU-875 preamp, which does add an extra but small Midas touch in musicality.

Rayaudio’s Signal Isolation Transformer Another essential mention. Ray’s SIT (L pic) is indispensable as it elevates the sound so much, not just in my system, but also in many other systems of friends! I’m eager to receive the 1:1 Transformer from UMI. It was raved in China's Hifi press. A comparison shall be interesting.

“Studer” Cables Another revelation. This cheap cable (yellow striped cable in R pic) actually is transformative, the more of it you add to the system, the more the return! It’s musical, smooth, yet has lots of details and a wide soundstage; most importantly, it’s not fatiguing to listen to. Currently, I’m using all Studer for signal, from Emerson to Elekit to Aiyima.

Now for treatment of some stuff that I haven't really covered in depth before.

Network Swtich I had tried a network switch. While it was a really good one that provided a lot of details and clarity that I had not experienced before, somehow, perhaps due to system matching, something was not to my liking and I’m still looking for an upgrade (like the SW8 from LHY, which makes me drool just by looking at the interior of the unit).

Luna Cables Luna Gris When it came to speaker cables, I was happy for a while with my Belden 9497, which bettered my previous Gotham. Then came Luna Gris, which I liked a lot. It was natural, never flashy. As a cheapskate however, while I thought I could gain more from their next level Orange (on loan to me by generous distributor Ray - so many nice Ray's) I resisted installing it into my system. No doubt it would further improve my system, perhaps significantly, but at more than double the cost of Gris! I tried not to open up the Pandora Box. Many months went by, and it seemed no matter how I tweaked my system, I could not tune it to my ideal sound. Luna Orange So I finally hooked up the Luna Orange. At first, I heard some difference, but it was not earth shattering though. I was patient and let it burn in for an extended period and things started to change. The overall sound had become more organic, musical and natural. Bass has depth and clarity; vocals are as genuine and natural as I would like; everything seems to fall into place and the music is very listenable. I could finally enjoy music but there was still something missing from my Level One expectation in the overall sound - but it was getting close though.

Viard Cables HD12 I always am interested in Viard. The French cable company's philosophy matches well with my audio beliefs. So, I bought a pair of their HD12 Speaker cables at sales price. Though it was not cheap, it was still relatively cheaper than Orange, and I was hoping I wouldn’t need to break my wallet for the latter. To cut the long story short, at the beginning it was no match for the Luna Orange, even after 2 weeks of intensive break-in. The Orange definitely had the upper hand in terms of detail resolution, naturalness and musicality. Against my cheapskate will, I began to think really hard that maybe paying the hefty price for Orange would still be worthwhile. Meanwhile, I had loaned the Orange to my friend Kwong for a few days and was making a last-ditch effort to try to live happily with the Viard HD12 …. But I knew I was missing the Orange already and was ready to check out at the counter…Then one thing happened that turned things upside down...

Enter the Ground Box from Entreq!
My friend who loaned me the Nait I loaned this ground box to me. A lot of people may have heard about Entreq, a brand that has a lot of diehard followers, and their product can sell up to over $200K USD!!! The entry model Micro Kit, just slightly larger than the power supply for my Aiyima, comes with a ground cable and sells for $250USD, which is very affordable compared to their top models, which can sell up to over $200K USD!!! It is said to be designed mainly for headphone amp and so I guessed it may be good for my preamp too.

My DIY troumaline ground box brought significant improvements to my system. I had also brought it around to try out in many friends' systems (including uber expensive ones) and had never failed to persuade them to connect their setups with either DIY or branded ground boxes to improve the sound. In general, the result is darker background and smoother sound, without the “noise” that sometimes fatigues people. Another important improvement is the heightening of the musicality, coherence and passion of musicians. This has been proven, but how is one box different from another? How will a DIY unit stand against a famous brand? These are things that I have always been wanted to find out; deep down I believed there would be some difference, but perhaps not a whole lot.

I brought the Micro Kit home and hooked it up immediately. At once, I heard a difference but, since I had only listened for 30 minutes and my boss took over the living room, I reluctantly retreated. The next morning, I listened to it briefly before going to work. I thought I did hear something different, for better or for worse, and that lingered all day in my mind during work. It felt like something amazing had happened to my setup but yet I could not fully grasp it at the time.

It did not take too much testing, and I was soon fully convinced. “Transform” is a word which I would like to use judiciously. I try to not use it too often so as not to discredit myself (much like Cry wolf). This time, I literally heard my system transformed from barely listenable to highly enjoyable! Another incredible thing is, with the Entreq the Viard HD12 became the Cable of Choice in my system!

...I finally bought a Entreq Micro Kit, which is a no brainer for me.

In Part II, I shall offer more detailed assessment.

Revox 720 722 Aiyima A07 A07 Pro Fosi TB10D Tidal

Click pics to enlarge. Note DG Karajan box on top. Bottom L is part of the DVP; to the right, the Gophert SMPS.

Letter from Shenzhen (23-3): Home Alone with Revox 720 722 Loose Ends
Streaming Classical (23-1): Karajan Haydn Mozart
Book: John Berger

Early on I decided not to go to Guangzhou and rather spend CNY by myself. Aside from the usual daily chores, I did a few things (not all audio related) which I shall record here. As during this time I had the Living Room (LR) all to myself, the first thing I did (on New Year’s Eve) was...

Reconfiguration of the LR System Before I was using various Aiyima products (mostly T9) to drive the Anubis LS3/5A (here). Since my main listening room, the study, now has transitioned to all-tube (here), I moved my trusted Revox 720/722 combo out to the LR and installed it. Chinese Bubugao DV-997 serves as CDP. Bubugao was maker of now-defunct Oppo, which were once widely popular (and perennial recommendations in trade mags) for their universal players. Mine is just an old DV Player, but a top one that is sonically superior (modified a little by someone in HK, then HKD 1K). General Sound Despite its relatively compact size, the Revox 722 has plenty of power to spare. Compared to the Aiyima T9 (run at 24V), sound is much more authoritative in my big LR (speakers are 2.6m apart, and I listen from the sofa, 3.4m away). This portion of the LR is 3.6m by 4.2m, but it is an artificial mental line, as the space extends much more to the left (the dining room and open kitchen) more than doubling the area. It is a joy to listen to the Revox pumping out juice, and the Anubis sounds significantly better than usual too. I mentioned to jules last night that a lesser system in a big room can be even more satisfying than a better system in a smaller room, and that may be the case here. No, it doesn’t quite have the details and refinement of the main system, but having music resounding in a large space is something else. Revox 720 Preamp As I needed at least 2 inputs, the preamp comes in handy. It also has balance adjustment (a slider rather than a knob, as is the volume), which is very useful for me, as I like to sit near the window rather than in the center. Which is also why I toed in the left speaker quite a bit. With the help of the balance feature, I can get the music filling out the center. This is also the reason why I don’t use the Aiyima T9 as Preamp, though I may re-evaluate it next round. I don't have much use for tone controls but would like a balance knob (unfortunately not present either on T9 nor my tube preamp in the study). The 720 actually has a decent tuner, but there are no classical stations here (HK has RTHK4). Aux vs Tape In I had the DVP hooked up to the AUX and the Aiyima T9 Pre Out to the Tape 1, and found that the DVP was much louder. Reversing the inputs brought the opposite. So the Gain of Aux is much higher. I only just now recall that the Revox Preamp has small screws below each input to adjust the gain. Next round I shall look into this to equalize. Aiyima T9 Now I had the Aiyima T9 connected to the AUX primarily to use it via its Pre Out for its Bluetooth (which benefits from higher gain). In Pre Out mode, the power meter cannot be relied upon for adjusting correct level. So it was empirical and more precise tuning shall have to wait till next round. I also did test the Aiyima as DAC. I connected the Coaxial Out (using XLR 0.4) and Optical Out (generic) of the DVP. Sound was initially comparable, but after some to and fro I came to realize that the DVP analog out is better with the swells of massed strings - just more real. And so I removed the digital connections. I may test out my other BT devices later, as it’s kind of clumsy to use the T9 only as BT via pre out. So much for this setup for now.

I get up early, usually around 6:30. The sky is still dark. After boiling water, I’d have some instant coffee, just for the jolt. Still considering a coffee maker (one more item on the cramped kitchen counter). Usually, I’d just read till the sun comes up. But in the past few days, I’d turn on the lamp by the sofa, turn on the system and start listening to CD, something I haven’t done for almost 2 years!...

KARAJAN Symphony Edition (DG), Haydn, Mozart This 2008 38-CD megabox is a great bargain, and solid basic repertoire. Amazingly, unlike many other boxes that come and go, it’s still in print, 15 years later, still at bargain basement price (Amazon is $53). I don’t have that many CDs here, though I have 4 boxes of Bruckner and 2 of Shostakovich (that shows you where my sympathies lie). What better music to play during the new year than Mozart and Haydn? I started with Mozart on New Year’s Day. It is not an exaggeration to say the music infused my soul and was uplifting. I soon went through all 3 CD’s. Karajan made some very good Mozart recordings before on EMI (overly reverberant acoustics) but these 70’s recordings have better sound. The execution is just perfect - one hears everything when one should, and nothing when one shouldn’t - artless indeed. There is little question that the BPO of old was much better than its impersonal counterpart today (imho, Abbado and Rattle ruined the orchestra’s classy sound). Down to the last piece, they are coherent and meticulously balanced - classical indeed. Then I moved on to Haydn, and it was an even greater joy. The Paris and London Symphonies total 7 discs, and I’m one short of the finish line. Not having re-visited these in decades (I have these on vinyl) I am highly impressed by the discipline and verve of the team - everything moves forward, nothing sticks out, and there are moments of humor and even Brucknerian grandeur. I grew up on the Bernstein, Ansermet and Szell recordings, but these are even better in overall execution (and sound). The only other one worth noting is Kurt Sanderling’s Berlin RSO set of the Paris (Eurodisc), absolutely proper and sonically superior (oop; but probably can be streamed). Of course, I’m not talking about HIP Haydn that is prevalent now. Mind you, I’m a fan of, say, the ongoing cycle of Il Giardino Armonico/Antonini (Alpha) but I think there’s more than a place for these grand old performances with big orchestras. Where the small HIP ensembles can deliver a shock, the bigger BPO can deliver grandeur, and that’s a completely different thing. To use an audio comparison, it’s almost like a small room compared to a big one. Karajan is not “known” for his Mozart and Haydn, but here I think he is owned his due. This box set is a contender in every composer and can form a keystone in one’s library. If you still prefer CDs, get it. You can stream almost all of it too.

Sometimes though it’s better to have no music at all. In the wee hours or first thing in the morning with coffee, a good book is bliss...

JOHN BERGER A Fortunate Man Despite the limited resources (in English), I’ve read more books here in SZ than most time in the past. I actually have a little personal thing relating to Berger. Many years ago, an artist friend of mine recommended Berger’s Ways of Seeing, but I forgot about it. A few years later, a Taiwanese friend was translating the book, and asked me to go over the proof. I did, and made many suggestions that she might not have liked. Truth is, as a sometime translator (erstwhile and amateur; I have done poems, art catalogs and exhibits etc), I realized the big divide between the very precise English of Berger and the inherently imprecise Chinese language. Then, I realized what a masterpiece the book is. Fast forward to recently, when I borrowed this book from the very limited English book selection of the local library. Like Ways of Seeing, it is one of the most engrossing books I have ever read.

Berger calls it an essay. It follows the practice of country physician John Sassall, and probes in depth the relation between the healer and his subject. It surveys the landscape of a less affluent sector of society. Importantly, it emphasizes the devastation of cultural deprivation - spiritual poverty. The work is prescient of our current society, urgently in the UK but just as true in the US. A social commentary and condemnation that is even more relevant today. Should you be interested, there is a huge amount on this book on the internet. I started it sometime ago, but finished it this CNY. Everyday I still think of the book - that’s how good it is. Of course, as a trained person in the field, I can easily relate to the subject, and indeed find the hero, practicing solo, highly skillful and, well, positively heroic.The only problem is, I have trouble thinking of what to read next. I may also write another short article on this book, as I’d like to share some of the texts with you.

More Aiyima Previously, I had tested out the Aiyima A07 (for many, a perennial fav) and its latest incarnation, A07 Pro (with the Fosi TB10D thrown in too). In preparation for writing a short article on the trio, I have re-listened to them in my main setup as well as the LR. Watch this space.

Tidal Some time before the CNY, my HK friend Sang/Seng, whom I had featured (as Home Visits) many times in the blog, surprised me by including me in his new Family Plan of Tidal. This had not come out of nowhere. Seng has always been an avid classical listener and loved to browse and buy CDs. For the longest time, I had been persuading him to start streaming seriously (he had Spotify, but the LOUD ads are basically intolerable), to start with Bluetooth for nothing. About half a year ago he finally capitulated and bought the FX Audio BL-MUSE-01 I had previously recommended in this blog (here). He was using its digital out into his own DAC and deemed it satisfactory. Not long after he established his footing, he took the leap and subscribed to Tidal! And so, I have Tidal here, and I love it for the pop and jazz on offering. I shall be penning a Tidal article, likely in conjunction with some of our other authors in HK.

Happy New Year of the Rabbit

Letter from Shenzhen (23-2): Happy Year of the Rabbit 兔

Addendum 1/23/23: In the wake of the Monterey Disaster, just read this excellent article on the meaning of Lunar New Year for an Asian American Chinese.

And so we said goodbye to the Tiger and welcomed the Rabbit. This being the first Chinese New Year without the Zero Covid policy, Shenzhen is as empty as I've ever seen it. Almost everybody emptied out and went back to their laojia (where they were from). In case you don't know, SZ had few indigenous people and was a sleepy town before China's Opening and almost all its current inhabitants hailed from elsewhere (for the economic opportunities). - an immigrant city. CNY in China is a weeklong affair, and the only time most people get to go home (kinda like Thanksgiving and Christmas)

The pic on the left shows the character Fu, meaning Blessing. The right hand portion though had been deliberately and subtly altered to make the character look like both Fu and Tu, Rabbit 兔 .

The Rabbit family in Chinese uses the same basic word Tu (with qualifiers in front). Hence a Hare is a wild Tu. Today a Chinese article used a hare drawing of Albrecht Durer. As he's a personal favorite, I am sharing it with you.

Aside from China (and Macau, Hong Kong, Taiwan), Chinese New Year is a holiday in many Asian countries with large Chinese populations (like Singapore and Malaysia, the latter a miracle given how racist their government acts towards citizens of Chinese descent). Korea too, because they also celebrate the Lunar Calendar.

This is an interesting one. Recife, the fifth largest city in Brazil, starting from this year has Chinese New Year as Holiday. Recife has been sister city of Chengdu and Guangzhou, and is grateful for China's help during the initial phase of the pandemic.

Finally, a video of last night (Eve) outside my windows

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

Telefunken 512WL radio renovation

by mrgoodsound

In December, I took my first real vacation from work in 5 years and this was my project: a Telefunken 512WL radio from 1935.



The radio came to me in an operational state so I wouldn't call this a restoration or repair. It was more of a 'renovation'.

This is a very simple three tube radio in a fairly compact form factor. It sports an AF7 driver, RES964 output pentode and RGN1064 kenotron. My initial goal for the radio was to serve as a control path which I could use to evaluate the sound of various passive components by placing them in-between the plate of the AF7 and grid of the RES964. Due to the high input impedance of the RES964 grid, various components can be installed in this location to have their sound colouring evaluated prior to installation in another circuit.

I removed the RF section and simplified the AF section as much as possible. This mainly involved putting the AF7 into triode operation with an anode resistor instead of the native choke. The choke will be recycled in another project. Further, the AF7 is operating with an 'open' grid (no grid leak or stopper resistor) and therefore receives much less than the 140v anode voltage indicated on the schematic. The anode resistor value was chosen by ear to provide sufficient gain without distortion. I settled on 100kOhm, receiving a plate voltage of around 40-45 VDC.

All the remaining resistors were tested for value and in the case of capacitors, leakage. Thankfully, no modern substitutes had to be used. A photo of the original circuit is below. Only very high quality Siemens manufactured parts.



And after 'simplification':



In the original schematic volume control was done capacitively in the RF section before the grid of the AF7. Since I have installed a RCA line input which I will only use with digital sources that already have volume controls, a fixed 1Meg resistor was placed between the grid of RES964 and ground. The signal (again, from digital sources with 0 DC offset) is fed directly into the grid of AF7. The chassis has a service stamp from 1941, but I could not identify what was replaced other than the output tube, which is a later ST shape. I have purchased a globe mesh RES964 for the sake of completeness. Though only made a few years earlier, it provided an even clearer and more expressive sound.



Despite its bashful appearance (the front glass dial broke in shipping and I decided to just do without it), the final sound exceeded all expectations. It sports a 7" electromagnet speaker which is probably the best speaker I have in house. It simply sounds more interesting than the various 10-12" Telefunkens I have from the late thirties. The speaker surround has suffered a number of tears which cause it to wheeze and rustle when excited at its resonance frequency, but I decided to just leave it as is rather than risk glueing and worsening the sound.



I have long been moving towards serious monophonic reproduction at home, though in the back of my mind I was sure the 'special effects' of stereo were still necessary for modern recordings. Now I am not so sure, and may move to listening in mono full-time after further experiments.



Two sound demos are attached to get a taste of the sound. I draw the listener's attention to the striking spatial impression and depth in Cash's voice, as well as the comfortable sharpness of Luther Perkin's Telecaster, the edge of which is somewhat blunted on YouTube compared to reality. The sound is rich in overtones with an infectious bass drive. I have listened to the radio continuously for many hours without getting tired. This is a new level of sound quality for me, and I am eager to repeat the results in a larger system.

Naim Nait 1 Revisited

Letter from Hong Kong (23-2): ELO on How GOOD is GOOD?

Naim Nait I Revisited.

https://m.youtube.com/watch?v=2a06ch6BlZw

I watched a YouTube video recently that really speaks to my heart. It is a review of a piece of vintage equipment that I was the proud owner of some 35 years ago, 1987 to be exact, and which has become legendary in the meantime - the original Naim Nait. In the review, one thing he mentioned struck me so much that I could not nod my head (and heart) enough in agreement: the music that comes out of this humble little box makes one think the performance of the musicians amply justifies their pay! This was exactly my belief! I got the same experience in my room of an apartment shared with friends when I first started to work after I graduated from college. Back then I used a Rega Planar 2, Naim Nait and Linn Kan, all first generation. Man, what a wonderful experience playing some cool jazz music (which was chic that time for a young lad trying to act like a mature person - before I actually fell in love with jazz). I then became a stereo salesman selling cheapo stereos to the mass. I often asked my customers to imagine that they were sitting in the room with a whiskey on the rocks in their hand, with lights dimmed out and with cool and smoothing jazz music playing through the stereo (what a lovely moment!) This description was simply based on my actual experience!! And as a result, I sold lots using this same storyline, LOL. Anyway, my Nait1 was given to my sister in HK and I got it back a few years ago but sadly lost it during office relocation...Luckily, recently I was offered a recapped unit for trial thanks to a generous music lover! Hopefully, I can measure how far I have gone from my 初心 [Editor: "Initial Heart", meaning one's goal or determination early on, with the connotation that they get weathered or even lost with time]!

During the search for Audio Nirvana, the road is rocky, and often I lost my 初心 or even sometimes came to a point of complete standstill, only to revive after a period of hibernation (much like what Dr John had gone through recently). Mind you, I have many different hobbies as well as personal issues to deal with - enough to be distracted.

Recently, like many music lover/hifi enthusiasts, from time to time, I have been asking myself or re-evaluating the question of what I am looking for in a stereo system. Am I contended with my current setup? Any room for further improvement? What is my ultimate goal to achieve in my system? Self-doubting is a disease, or simply a common character for a "ma fan" (troubled) hifi enthusiast. We were thought of by others as trouble seekers!

How much detail is needed for a music lover to enjoy music, or is it just the audiophile (running the mill like a Guinea pig in a cage) just endlessly chasing the last bit of irrelevant detail from the recording? There must be a point in the chase when one has to call it a stop....

Like me, other friends I know have been consistently upgrading their systems, with different speeds and each with his own holy grail (there are surely numerous trails). Some like to upgrade bit by bit and enjoy the slow burn; some try to leap to almost the end point by acquiring top gear regardless of any monetary concern. Some stripped out hifi attributes and search for pure music enjoyment by using vintage gears. While some focus on certain trees in the forest, opt for certain types of music, say, those with less dynamic requirement, in a smaller listening environment. Whereas for me, I am fascinated by 刀仔鋸大樹，i.e. using cheap equipment (not necessarily cheap sound) and cheap tweaks to achieve effect of acquiring mega buck equipment and I stand by keeping my inventory minimum by NOT collecting more equipment than I actually need. 

I think I am the greedier one, as I simply want it all but would spend only minimum amount of money! That's a tall goal and, of course, the road is even more rocky and painful, as well as fun. Perhaps deep down I don't want it to end soon and hence set this almost unreachable goal!

With each addition or subtraction of equipment, cables make a difference, but whether it is favorable or not, one need to really put his ears on to listen critically. I am all for cheap cables but somehow a well-designed but expensive cable does make a huge improvement. I don't like blanket statements, such as expensive gear are overpriced only because of audiophile demand and vanity. When I test a cable that is uber expensive to me, I won't deny that it has transformed my system's performance if that's the case! 

Do I need every musician standing in my living room to play the music? Or do I need to hear the singer exhaling the faintest air into my face? What about the deepest bass; pristine and crystal clean treble that do not pinching your ear; midrange that is lush and with intensity? How good is good? 

I had been eagerly waiting for the arrival of NAIT and hoped it can humble me and be a beacon for me in search for Audio Nirvana! Yesterday, the NAIM Nait 1 finally arrived, and I immediately hooked it up to my WEA. I used DIN adaptors with my "Studer" cable for interconnect. For the speaker cables, I used the newly acquired Viard HD12 bought at a sale. I used it in lieu of the other loaner Luna Orange cable, which I think is superior to HD12 but Nait1 does not take spades and only banana plugs...LOL

Nait 1 surprised me with its capability to drive my Dynaudio Crafft  to an acceptable level with volume knob dialed up to only 9 o'clock! I am enjoying music coming out of this setup. With adequate dynamics and intensity, and it can play music at a realistic level!

I began to test music (both Youtube and Tidal) played through my Bluetooth (TV, Laptop and Cellphone) on my Aiyima A08 and they are also very enjoyable as well; even if my laptop has a slight edge, I can live with all three devices! If I am not critical about the imaging, the depth of soundstage (by all means already quite acceptable to me), I can surely spend all day listening to music from BT!

Suddenly, I remember a scene a few years ago, when my friend, who is a committee member of HKIPF, a respectable photo organistion in HK that holds high quality photo exhibitions from abroad as well as promote local artists, asked me if I would want to hold a photo exhibition. At that time, I had only picked up photography for only slightly more than a year and I had never dreamt before that I could achieve this goal so soon. But he asked me a very interesting question: do I mind loose, out of focus and blurred images in my works? I said I don't mind as, if done well, it could add a special feel and ambience to the works. Suddenly I felt relieved and eventually held my first solo photo exhibition based on his great help!

Since I am not a "pixel peeper in raw file" type photographer, naturally I am also not the type of hifi people who must chase down the last bit of detail in the recording. As long as the music is true to the original recording (as far as practical), there's no point in chasing the perfect sound - just sit down and enjoy the music! 

Now I am more at ease. What's the point in chasing the extra detail retrieved, the clearest high's or lowest low's or truest in-your-face mids? As long as the picture is portrayed well enough and holistically, that will be more than sufficient; the others will be nice to have, once the fundamentals are achieved.  When in doubt, music always comes first!!

So much for the conundrum, and I hereby wish everyone gets closer to their own holy grail and reach their own Audio Nirvana in Year 2023! Just remember, it's the process that one should cherish and enjoy. Hifi is the means only; enjoying music is the main goal!! 

Happy New Year

Letter from Hong Kong (23-1): Happy New Year from Shawn P.

Editor: I'm happy to present our new author from HK. Below is the brief history I solicited from him. Although highly experienced, he's for now confined to a much less than ideal smaller space in HK (plight of many audiophiles there). But he soldiers on, even with his bad back. I reckon he shall have a few surprise articles for us in 2023.

"Path to being an audiophile", is only a path; and whether I have reached “audiophile” status is another matter.

How far should I go back? Things that took place in the eighties were mostly based on myths and misconceptions. My view of good sound was cassette tape (preferably metal tape) played through Sharp GF-777 or Pioneer J7, and a Hi-Fi system must have a 31-band equalizer with flashing lights.

Many of these myths and misconceptions were destructive. They do not contribute to the path to being an audiophile. Perhaps later I shall pen another discussion on teens’ myths, and misconceptions from the eighties.

That said, my path began sometime in the mid-nineties when state of the art home internet was 56kb/sec (theoretically, and only under perfect conditions), I was studying in graduate school back home (at that time) in Texas, and everything was at least 10 miles away.

All these plus others defined my path. First and foremost, there was barely any information on the internet, there were not many dealers carrying good products. Best Buy and Circuit City did not have any “audiophile” products. Hence, it was not easy for me to come into contact with any good stuff.

As there was not much on the internet, I mainly obtained my knowledge and information from Barnes & Noble and Borders Books, where I could read all Hi-Fi magazines without being disturbed. It was nice.

One magazine stood out for me, “Stereophile”. Sadly, most equipment reviewed by Stereophile was very expensive and I had no idea how I could get my hands on any of them. I would also read the small advertisements at the back pages of Stereophile and I was able to find some reasonably priced items, including items from my favourites (still are) “Moth Audio” and “Fi Audio”. Coincidentally, they both sold a 2A3 amp for under USD1,000. They are both defunct and I regret I did not purchase any of their 2A3, as I then knew I would go back to Hong Kong in a year or so, and at that time a thousand something (including shipping) was plenty. In addition, I was not sure what I could do with only 3 watts.

But still, I wanted to build a system and I purchased the only thing I could afford from Stereophile; a pair of NHT Super Zero. USD 99.99 each, not bad. I cannot recall how I came to purchase the rest of the system; perhaps, based on the marketing write up of the Crutchfield catalogue.

That was an age of lack of information and most purchases I made were based on not much information but that was the time I began to evaluate a system based on sound and not visual clues (31-band equalizer…).

I went back to Hong Kong in 1997, and the scene was completely different from Texas. I could then get in contact with plenty of equipment easily. Just one stop usually would carry many brands and models. I also found “What Hi-Fi?” which reviewed more affordable equipment, and better yet, I could test drive most of them in local stores. Great!

What was more? The internet was blooming and even though it was still mainly dialed-up connections, there was more information.

My decisions then became not as blind and, sure enough, my first system in Hong Kong (IMHO) was much better than the one in Texas. You may ask what the components were: CD and amplifier were both Cambridge Audio, speakers were Mission. They were very affordable.

So far, everything then was solid state, but I am now mainly a tube person with only one cheap Emotiva solid state amplifier for reference. So, what changed and what happened?

Hong Kong's economy was pretty bad in 1998. 1997 was a peak and not long thereafter things went off the cliff. Needless to say, Hi-Fi market also went frozen in Hong Kong. I had wanted to get my hands on a tube amp mainly because I was given to understand that it would solve my solid-state fatigue syndrome (i.e., too much odd order distortion) and I thought it would look cool in the dark with the glowing light (I found out quickly that the tubes did not glow as bright as shown in the photos).

I read the local Hi-Fi magazines and there were plenty of cut-throat sales advertisements that caught my eyes. An ad from “勁旺音響” selling Anthem Integrated 1 for HKD6,000. I found enough information on the internet and realised it was an exceptional price. So off I went to Mong Kok and got one of the two remaining Integrated 1s. It was brand freaking new! [Editor: Footnote 1].

First time with tubes: I did not know much and everything was surgically careful. Checked the numberings of the tubes 26 times and finally I got the balls to turn the Integrated 1 on and thought it could be the end of my life if things started to explode.

It turned on and nothing bad happened, as mentioned. I was disappointed to see how dim the tubes glowed. It sounded very good, no solid-state fatigue (although it was a hybrid amp, Class AB) and it was a piece of equipment from a different class. That was the end of my solid-state path.

Economy did not get any better; in fact, it got worse. Better deals appeared and there was one I could not pass on, Unison Research Simply 2 and a pair of Klipsch Heresy II for under HKD10,000 total and brand new [Editor: Footnote 2]. I was quite happy with the system and in fact, the combination of Simply 2 and Heresy II is still among the best sounding, even as I can remember now.

A few years later, circumstances changed, and I no longer had the space for any system; my path had ceased to fo forward and I went into hibernation for a decade. It went completely dead in fact.

Fast forward to 2012 - technology and the internet had advanced. When I woke up from hibernation, I discovered many new things, foobar2000, Airplay, FLAC, ALAC plus more. I thought it would be easier to start a system again. I lost my Integrated 1 and Heresy II, and my Simply 2 had some issues. Fortunately, I also found out the Chinese Hi-Fi equipment had also advanced greatly and there were some good tube amps for not much.

I could no longer afford any foreign brands and I decided to try out Line Magnetic LM-211. I could not be happier especially with the price I paid. I am still using the LM after 10 years and it has been great.

The advancement of the internet certainly helped: it became much easier to obtain information and I was able to catch up quite quickly (such as reading this blog). The improvements of Chinese manufacturers also made the ecosystem more interesting. While it is true that the foreign brands are mostly not affordable, I must say that it is quite interesting to purchase equipment from TaoBao and try them out. Should anything go wrong, it is possible that I may be able to find a solution online. If not, try something else as they are mostly affordable.

How about a 300B amp for HKD 2,500 shipped? Not perfect but it sounds good. I believe it has only been possible in recent years. At least in Hong Kong, since Taobao shipping was not as convenient a few years back.

So, ladies and gentlemen, Happy New Year and enjoy all these new developments!

Editor's Footnotes: 1) I was there when the shop opened, with a cheap offer of the AIWA Discman that has a Digital Out, the kin of which was praised in the magazine 音响之路. It was very good (I was using I think an Audio Alchemy DAC)! And it stirred a couple of my colleagues at CUHK to acquire CD-Roms with Dig Out as source. I still have the thing in HK! Mr Jiang 蒋 is a nice guy, those were the days; 2) And our footsteps overlapped again! I got then an open-box Unison Research Smart 845 monoblocks for an irresistible price - great amps!