Douk T8 Pro PJ Miaolai SA-1000

Click pics to enlarge. Douk T8 Pro. If this were a US or UK or EU Brand, even one manufactured in China, it'd cost at least multiple tens times the cost! Bottom, Knobs. Far right is the Balance (nice!), which can only be turned by a Philips screwdriver. Second from right is main Volume knob. To the left are 7 for Equalizers. Far left is on-off switch. Behind the Volume knobs and near the tube sockets are 3 JRC2068D Op Amps seated on sockets. The ones behind the Euqalizers are N5532. The Tube board is removable so one can modify the caps, but there are so many of them I have no idea what is what! Maybe time to find out. 

Letter from Shenzhen (24-2): 3 Preamps, 3 Amps and 2 Loudspeakers

Douk T8 Pro, Part I

Douk T8 Pro, Part II here; Part III (on XLR use) here.

Why should you be a long term reader of this blog? It's very simple. Aside from the fact that very very few trade or e-sites refuse monetization (think the garbage ads 6 Moons pile on you page after page, which is why I hardly read them and try never to cite them - I despise them, and shame on you if you read them regularly for free without thinking about your mental cost), very few audio sites re-visit audio equipment regularly (Stereophile commendably has some periodically and HiFi News has very good referencing to older versions too).  Very few sites even mention older equipment (Thumbs up for Stereophile to continue to upload their vintage contents, and HiFi News to have Tim Jarman's Column on vintage stuff). We do here, and we sometimes re-think our opinions. And you shall find some examples below if you read carefully. Grant you, we mostly "review" el-cheapo new stuff or re-visit older stuff, but we do it very seriously. We tell it like it is, over a long period. This article is both an update on some equipment previously covered, as well as the introduction of 2 new Preamps. Not earth shattering things, but interesting nonetheless. As for music, at least for classical aficionados, our coverage is concise but very good.

In fact, I think the best thing about our approach is to tell you how to go about it, or rather how we go about it, not what is better than what. One can learn from the most simple experiments. To achieve good sound, one must listen a lot and read less (apart from this site, since it won't empty your wallet, LOL). Especially, you should not read sites like Audioscience. The measurements are OK, but the opinions are trash. Subjective evaluation is kintergarten level. I have only contempt for them. But they sell. It's a pity Chinese manufacturers routinely send things to them, even high end stuff like Matrix.

First, some catching up, or what I'm doing.

2 Loudspeakers (Beydas/Stirling LS3/5a Redux)

I direct you to my article that describes when I just came back from the US a few months ago. My Beydas "LS3/5A" "11 ohm" (basic info in Chinese here) sounded deadly dull. And I spent a lot of time to get the "old sound" back. It came back eventually, but I never was sure of why. Such are the vagaries of HiFi sometimes (whole process described here).

BUT, I got a new angle maybe a month ago. I swapped in the "15 ohm" Beydas "LS3/5A" (basic info in Chinese here), and the initial sound was not good at all either. Yes, more open in the treble (it has always been the case) BUT seriously deficient in mid-bass and bass ("official spec" has it as 10 db less extension than the "11 ohm"). Now, this was a virtually new pair, because when I went back to NYC last time, I gave my run-in pair to Andy. As I ran them in over a month, the sound gradually became fuller and some useful bass emerged. Right now? It's marvelous! I just listened to Sibelius Symphony No. 4 (Gothenberg SO/Rouvali, Alpha). This is a heavily brooding piece. Although this version is distinctive and lighter than usual, the double bass must have impact and, when partnered right, it does. In absolute terms, with the 3/5 it's just a hint, but that is more important than anything else. A hint of deep bass is a tactile and suggestive bass, very worthy (even the real LS3/5A is like that too, just a hint). Wonderful!

Yes, right now, despite the lighter bass, the "15 ohm" sounds better than the "11 ohm" but it had on occasion been the opposite before. One thing I did think of: If you haven't used a loudspeaker for a while, it takes a while for it to re-capture its former prowess. YMMV. But, if you use flea powered amps like I do, it makes sense.

2 Amps (BRZ FU-50 and SE 6L6) and Another (APPL 300B) Redux

I had spilled much ink on these 2 BRZ amps, and they remain my daily staple. It's really astonishing how much improvement I got from "upgrading" the stock Rifa caps with USD 0.25 "Solen" (here). Both opened up considerably in soundstage as well as enhanced in tonal opulence! The FU-50 (basic info here) remains ahead in most respects (though the 6L6 [basic info here] is likely fuller in the bass). Both are just super bargains! Now that kits like Elekit (which I have long championed before but have reservations now) have gotten over-expensive (and unnecessarily big) I'd urge starters to consider these 2 very cheap amps (that come with useful tubes, not as extras). Mind you, like my favorite Sun Audio, these are simple, pure tube in the signal path (which I usually prefer, but not always), whereas Elekits now are very much solid-state-regulated in the control grids to achieve higher power and better dynamics. I actually have no qualms about things like solid-state use like constant current source (my ICL amps use that); it all depends on the resultant sound. I do think I can hear a trace of ss influence in the Elekit, but not in ICL. As for the cheap stuff here, as you can see from the links, aside from swapping in other tubes (still cheap), IF you can solder and change just a wire or two and swap a cheap cap in you can gain a lot!

Unlike Aiyima and Douk, with whom I have some kind of loose relationship (always declared) I have none with BRZ. In fact, I probably frown upon BRZ's voracious replicas of solid state FM Acoustics at super-bargain prices (though I'd not mind to hear one in my own setup if I get the chance). Price is their advantage, but I do believe they have a certain know-how: to make the best sound just above the technical safety red line (and that is why I'd NOT recommend you to plug in KT66 in the 6L6 amp; I have GEC KT66 but I'd not use it - also as US 6L6GC sounds just delightful in this amp!). Within limits, these amps run in my system hours a day for months without any problem. That's good! I've QC'ed it for you (and my samples are like yours, just randomly ordered from the net), provided you stick to rules.

But hierarchy remains. The Ultralinear 6L6 (or EL34) is still not as tactile as the FU50 run as Triode, and the FU50 still does not have the full sized presence of the APPL 300B amp (here, as yet still bone stock!). But switching between them is fun, and it reminds one that Ultralinear is not quite Triode, and running a Tetrode/Pentode as Triode is not the same thing as a Direct-Heated Triode. This has always been my long-term belief and this humble trio actually confirms it. There's no end to comparisons, and this blog compares more stuff than others. My point is you can learn a lot from even cheaper equipment (provided they are good). If you buy all 3 of these it's still way cheaper than a stock Elekit without tubes, but I wager you learn a lot more.

New Production Tubes

ALL these sellers out there say to you, this 300B is better than that one but few of them have really heard the old-stock WE300B's. I tell you ANY new one will not match up against old stock. I refer you to my recent article. That's not a sound you can get from buying an expensive replica tube today. So much nonsense out there it's really astonishing! IMHO, one should start with an honest and reasonable modern 300B tube, like the affordable Linlai that comes with my superb APPLause 300B amp, or a Russian basic tube. All so-called upgrades, like graphite or mesh plates, or gold pin this and that, sound different, but better? Not to me. YMMV. New "Western Electric"? Takatsuki? No thanks to all of them. In case you're interested, here's a 300B Shootout, from more than 20 years ago, LOL!

If someone has the dough, more power to him! Spend a lot on tubes is OK, but I'd buy only old-stock tubes (for 300B, WE before early 80's). Even if I have the dough, I'd NOT buy any of these boutique replica power tubes (be it 300B, 2A3 whatever). This is to emphasize that it's ridiculous for someone on a budget to spend more on tubes than the machine. Put the ridiculously priced current production "WE" 300B in an Angela amp and it's still an overpriced mediocrity. Better, put them in an Elekit, but it's still an Elekit. This is true for boutique components too, be it expensive caps or resistors or even transformer swaps. There is only so much improvement one can get from tweaking. Cheap mods are a lot of fun; expensive ones almost always end up in disappointment. No matter how you mod a Subaru it will not be a Ferrari; better enjoy the Subaru as it is!

Unlike most reviewers out there, I have been a tube addict for over 30 years, and I have a huge stash of very worthy old-stock tubes (and even more lesser ones, LOL!) In terms of tubes, I can max out the potential return in almost any amp. I can tell you what's a worthy upgrade and what is not. Driver tubes are worth experimenting with. As one goes down the line, the tubes become more useful. It's always good to have a few 12AX7 and 6SN7 around, for example, as they are used in so many amps.  I sympathize with beginners on a budget. They read everything on the net, and end up buying different Russian and Chinese tubes of little import, when they should take the bigger step and bid on some good used old-stock tubes on Ebay etc. Power tubes are more problematic but, as I say, I find modern boutique tubes underwhelming. As mentioned above, I'd not spend too much...Last, incidentally, personally I feel Russian and Chinese 300Bs are very good tubes because 1) they have been making these for decades; 2) perhaps Triode are easier to make than Tetrodes/Pentodes with their additional elements; 3) I bet you Chinese 300B parts are used in many other boutique 300Bs. There is a huge amount of undesirable trade secrets out there. As for other DHT like 2A3 and 45, modern ones are just basically tweaked out 300Bs.

That's a lot of digression. Now to the Main Course.

3 Preamps (Eastern Transmission Audio [ETA] 6N3, PJ Miaolai SA-1000, Douk T8 Pro)

This came by in an unusual way. As I tube rolled the BRZ A08 6L6/El34 Amp I employed some better sounding but lesser gain tubes, like the 6SN7/L7 (with adaptor). As detailed in the link above, I prefer the larger envelope tubes (as usual). Which means there's an opportunity to use higher gain tube preamps. As mentioned in the link also, I tried the ETA 6N3 Preamp, but its defective volume pot makes it impossible to get a proper volume.

So I dragged in another two candidates...both are hybrids, tube buffered IC Preamps. Both are debutants here.

https://m.tb.cn/h.5rIMhYx5izOLuU2

PJ Miaolai SA-1000

I actually still don't know why I bought this. During a previous 11.11 it was just so ridiculously cheap at barely over 200 RMB (around USD 30) that curiosity got the better of me. I actually got it before I got the ETA 6N3.SRPP Preamp. Reason? This came with a pair of Russian 6N3 so I later ordered the ETA without tubes at a savings of 50 RMB. Cheapskate, yes!

This is a Preamp, with 4 Inputs and 2 Outputs. It's based on the N5532 Opamp (not easily replaceable). It sports dual Tone Controls and Headphone Output. It runs on 12V DC (I used my own heftier SMPS PS). One Russian 6N3P in each channel serves as buffer (probably just paralleled, unlike the ETA's SRPP). More in pic at bottom. BTW, there is a new version with Bluetooth and remote control. Caveats The RCA sockets are of the most "basic" quality, which is true of many Chinese products at this price level. The outer casing of one got stripped as I pulled my MIT T3 interconnect out. Yes, this happened to my 6J4/6P6P preamp too. On both, 1 down, 3 to go. Make sure you don't use connectors that grip too tight.

When the PJM arrived, I fired it up and was assaulted by the crazy high gain and grainy sound and basically put it aside for a long long time. I never thought I'd write about it. I basically wrote it off!

Fast forward. I poached the stock Russian 6N3 for the ETA Preamp. At first, it was not so good, but after some mods and a hiatus, it was suddenly OK (chronicled here). And so I enjoyed the ETA for a while.

Fast forward to now. Since I could now use a higher gain preamp with the BRZ 6L6 Amp I decided to give this PJM Preamp a try. I put back in the 6N3 Russian tubes and was surprised. Perhaps due to the fact that I have run the tubes in thoroughly in the ETA, it had become much smoother. In fact, the run-in Russian 6N3 (and perhaps the run-in preamp) seems to be be fairly smooth. Too bad I don't have any WE396A/2C51 or even 5670 around (not even in HK).

vs ETA Comparison with the ETA (both using the same set of Russian 6N3) was fascinating. The all-tube circuit ETA (SRPP), which has had its caps and hook up cables modifed (link above), sounded not quite as fast as the also high-gain PJM. But the basic sonic signature is very similar, not surprisingly since they use the same tube. The midrange is virtually identical. The ETA has a little more top-end air and nuance, but turning up the Treble a little on the PJM brings the two closer again.

Headphone Output I tested it with my Grado SR-80E and it was decent enough!

https://m.tb.cn/h.5qKXYRImLH9oJ04

Douk T8 Pro (7-Band Equalizer Preamp)

This is a fascinating one. It stands out for having a 7-band Equalizer. Also, it has both Balanced (XLR) and RCA Inputs and Outputs (just one set each). My unit is on loan from Douk. Again, this is an Opamp based Preamp (JRC2068D and N5532; see top pic for more detail), with Russian 6N1P buffer. Runs on 12V DC. Price is around RMB 650 (USD <100)

I don't have any balanced stuff here in SZ to try it out, but keep in mind that it can serve as an XLR to RCA convertor and vice versa.

I ran it first with the stock Russian 6N1P. Sound was surprisingly decent. Even then, I noticed that the sound is faster in transient than either 6N3P Preamps above. As I use my own SMPS PS with digital display, I noticed instantly that this preamp draws a much higher current than the others. At turn on, it transiently hits even 1.5A, but very instantly normalizes to just under 1A. Not surprising, as there are a total of >10 Opamps in the signal path alone. This is double the current of the 2 preamps above. With all the Equalizers flat (12 O'clock) sound was a shade plain, perhaps even betraying its opamp origin, if just a shade. So I proceeded to:

Equalizing The Equalizers are centered at 50, 125, 315, 750, 2K 6K, 16K Hz. I'm not at all a student of equalizers, so I don't even profess any knowledge about whether these are effective points, well chosen or not. I also don't know the slopes nor the +/- db offered. Just like how I dial in subwoofers, I think these should be used judiciously and with great restraint. As my system is fairly balanced and neutral, I felt no need to equalize at either end. Instead, I almost on impulse, and randomly, bumped up the 750, 2K and 6K to around 2 O'Clock. The idea was to raise the (upper) midrange a little. Well! It worked better than I thought! First, the slight paleness filled out. Any negative effect of Opamps was diminished. These settings worked for me, but for your system it might be otherwise.

Tube Rolling Unlike 6N2, where you have to use an adaptors to roll tubes, and unlike 6N3, where there are few substitutes, 6N1 has pin compatible direct substitutes. You can directly plug in 6DJ8 (family) and 6CG7. These are tubes that many people who play with modern stuff like Schiit have in their arsenal. I just happened to have brought some of these over for my BRZ amp tube rolling using 6N2 adaptors. 6DJ8 The Amperex Holland brings about a much greater refinement than the stock Russian 6N1. 6CG7 But my heart belongs to these. The Matsushita were a shade dry, but the GE proved just about perfect. Moist, but dynamic and refined. Now, where are my RCA Clear tops? Tube rolling effect is greater than equalizing. Some people would say that, though pin-compatible, these are not exact equivalents. But, why worry? This is all about equalizing, right? After I rolled in the 6CG7 I felt absolutely no desire to roll others and proceeded to compare:

vs 6N3 Preamps The Douk sounded so right that I totally forgot it has Opamps in it (especially when equalized). The low strung PJM didn't really sound transistory but in comparison was less three-dimensional, and smeared in terms of imaging. Even the all-tube ETA fell behind. By a good margin, with the transient sharpness, airiness and good tonal control, the Douk simply sounds more present, and involving, and by a good margin.

vs Douk E6 This article took a long time to write. I compared the participants multiple times, both with Russian tubes and with tube rolling. Now, with everything going on, I haven't fired up my Douk E6 in ages. Despite its quirkiness regular readers know how much I respect this little gem. Suffice to say, equipped with the GE 6CG7 the Douk T8 Pro did not loose too much ground. Best, it conveys the drama and narrative in the music as well. The E6 is for sure a little airier and luxuriating in the treble but not by as much as you think. That translates to great praise for the T8 Pro.

Suffice to say, lately I have been largely using the T8 Pro. I periodically rolled in the ETA and the PJM but I always revert back to the T8 Pro. That says a lot. I think I'd purchase my sample.

Thoughts

• 6N1P vs 6N3P Based on this limited experiment, I'd say it's more fun with the 6N1P, more rolling old stock possibilities!

• PJ Miaolai This is a pretty good Preamp, but not in the first tier. For its ridiculously low price, it can serve as a good switchboard, with 4 in and 2 out! AND, Headphone Output!

• Douk T8 Pro This is an excellent Preamp! Its Equalizers can even out its own mild deficiencies, and maybe your system's! I'm pretty sure I've not gotten to the bottom of it! For those who run both balanced and RCA, it's even more useful! Highly recommended! A niche product, but one that I heartily endorse.

PJ Miaolai. Engineer David of UMI said this is a poor layout not designed for the best sonic outcome. No matter. I wonder if the 2 Blue Caps are for tube coupling. 1.0uF 100V only.

Aiyima A07 Max vs A08 Pro

Letter from Hong Kong (24-2): ELO asks: Aiyima A07 Max, better than my A08 Pro?

Readers know that I'm a big fan of the Aiyima A08 Pro (here). Lately my system has reached an equilibrium that I spend much time listening to music everyday instead of worrying about what I have missed on this and that. Is it perfect? Not really, but I believe my current setup can compare nicely against many setups which are many times more expensive than mine. (Every HiFi lover has this objectivity implanted in their heart~)

I have been toying with a decent LPS for my Wattson Emerson. Or upgrading a cable or two (maybe Viard? A French name with products that are amazing for their price, not cheap but really good value). Of course, the "Studer" cables that I am using now are no slouch at all (here)! 

Or perhaps I should replace my A08 with a Hypex, Purifi or GaN Fet Class D? 

While I am constantly looking for my next upgrade, I have also noticed that Fosi has released some interesting products like ZA3. Also the latest Aiyima release of A07 Max had really caught my attention. By cutting down all the bells and whistles and using higher grade parts by Wima, Elna etc, has Aiyima produced a pure amp that can compete with the elite names and claim itself as a legitimate giant killer?

When it comes to budget amps, a lot of Youtubers have reviewed them, but only to match them with inferior equipment which do not do justice to some excellent products. They seldom assess these budget products in a serious manner be examining all hifi attributes. Often, I hear  "it does has a lot of power...clean and can be the best desktop amp and for this price...it serves nicely as an entry product of hifi beginners!". Very few people are as crazy as DJ and I trying to feed all the goodies to budget equipment to get amazing results. Most reviewers always miss the point and treat them as cheap amps and often biased with "cheap amp expectation" embedded into their minds, with which I do not agree at all.

Before I have drifted too far with my conundrum, I pressed the button and ordered the A07 Max and it arrived at my door in less than a week's time. All I was worrying about was that A07 Max does not have bluetooth and I cannot connect it to my TV and WEA at the same time. I was quite convinced by the brilliant specs of A07 Max, and even hoped it can dethrone my A08 Pro. I did not buy the power supply and instead used the one that came with A08 Pro, so I could compare apple to apple.

After listening to the A07 Max for 5 days, I unhooked it and put my A08 Pro back again to hear the difference. I also realized that I needed to max out the A07 Max in order to match the A08 Pro at 11am position.

Put it this way, unlike many reviewers' view, my conclusion is that all budget Class D amp are NOT EQUAL, even under the same brand name! They do sound different and the difference is not small at all!!!

When I first hooked up the A07 Max, I sensed an improvement in the coherence and musicality of piano notes. However, the bass was so subtle that I could follow the bass line, which is not a good sign. The highs were simply missing the air surrounding and decay of instruments. This separates a high end gear from the average off the rack stuff. Yes, the A08 Pro is a special product, indeed.

I came to realize that A08 Pro is a little gem that A07 Max is not able to match! High end parts simply fail to give A07 Max the edge. With the A07 Max, highs are missing like a head being truncated, and bass is light footed. A08 Pro also does have way better separation of images. Also, harmonics are much better heard in the A08 Pro.

I have to give the A07 Max a pass this time. Or simply put, the A08 Pro far exceeded my expectation and is firmly embedded in my setup at this moment. If the A08 comes out with a Max version, I would be very curious. 

There are a lot of interesting Class D amps in the market which I am interested in, but some are out of my budget like the AGT, SPEC, AAVIK. One can buy a cheap amp to review even if it fails expectations, but one cannot do that with much more expensive stuff.  It is important to hear something and to evaluate. This is part of the reasons that my A08 Pro is still firmly embedded in my system.

Well, I have full confidence that the engineers at Aiyima will straighten things out given I already know they can design a great product like A08 Pro! 

Editor's Note: Some months ago I actually briefly heard at Aiyima headquarters a comparison of 3 amps, the original A07, the A07 Max and a Fosi amp (don't remember the model). The original A07 was coherent, warm sounding but not the last word in details. The A07 Max sounded completely different. My feelings then mirrored what ELO wrote above. Not much air in the treble. What bothered me about the bass was less the quantity than the timing; in fact, I thought rhythm and pace as a whole were suspect. On that occasion, I thought the Fosi, though as usual on the hifi side, to be the better performer. Based on my impressions then, I decided not to take home the A07 Max for further audition. But do note that the listening session was short, with rather bare bone ancillary gear (same as before, see here), much unlike what ELO used the amp with. Also, I'd like to remind readers that I've actually heard the A08 Pro in my own home; see Editor's Postscript in ELO's review (link at top).

Before I edited this article, I actually read the audioscience "review".  As usual, aside from the measurements, the "review" and "sonic assessment" are a joke. YMMV.

I don't knock all these technology. More and more very big names have embraced digital amp technology. I have heard at shows some of the amps ELO lusts after, and they can sound decent (have heard at least SPEC and Aavik). Indeed many very expensive gear now use SMPS too. Each has his own way to improve things. But in the end proof is not in the measurement, it's in the listening. The better the ear, the more discriminating. Not everything that measures well sounds good, but like ELO alluded to, there are just too many bad listeners passing as critics out there.

優美 (UMI) 1:1 音頻牛

優美 (UMI) 1:1 音頻牛 (之 一)

https://m.tb.cn/h.5SXf9su?tk=zfPQWYBSWYJ

ELO 用英文作的評述

雖然筆者已經知道這神器的存在超過壹年，也在自己系統用了超過幾個月，也構思了要怎麽報道，動筆卻是超乎意料的難。筆者是壹個英文音響博主 （系屬谷歌，國內看不到），但中文寫作沒有問題。難的是這個東西對壹般發燒友來說會有點“神”，需要解釋爲什麽要用它。很多人，包括筆者，是所謂簡約派，認爲 ”多只香爐多只鬼“。但是，西方人有壹句話，Simple but not too Simple, 即 “簡單，但不能過于簡單”，值得借鑒。如果妳是屬于相信訊源直入後級，沒有前級最好聲那壹派，可能不需要看下去。

先說自己，讓讀者有個出發點。筆者沈迷音響四五十載，因爲常年在國外，造就了我玩了非常多難得的古董和現代經典器材。雖然是個膽迷，但我也有選擇性喜歡現代器材，尤其數碼音源部分。重要的是聲音平衡。非常多古董派發燒友搞出來聲音朦胧，廣東人可以說“朦過華秀只狗”。但該有的應該有，不該有的可不可以有！壹個好的系統聽所有音樂都佳宜的。匹配得好，什麽理論都可以抛擲腦後！聲音平衡是必需的。

什麽叫匹配

筆者不是工程師，數據上懂得只是皮毛。可是對聲音肯定知道好壞的。我相信這裏的讀者大部分都是有基礎的，可能大部分都多元化，有用前後級。先說前後級配搭，最簡單的問題是後級輸入靈敏度，高的甚至可以不要前級 （如古董 Leak，現代 Audio Note 後級）；低的非常需要增益大的前級（如 古董Quad II）。但這只是最簡單的問題（雖然發燒友也忽視）。

更困難的是阻抗匹配問題。簡單地說，任何有輸出的器材都會要面對後面的阻抗，二者不匹配頻寬會受到影響，可是沒那麽簡單。理論上，石前膽後可以非常優秀，但事實上膽前石後更加討好（筆者這樣認爲）。音響的複雜性是因爲音頻在不同頻段線性不壹致。所謂阻抗是動態的，不是單理論可以概括的。也就是說，最後只能耳朵聽了算！

最簡單地說，壹個好的1:1音頻牛，用在兩件器材中間，可以幫助藕合。拿優美來說，前面的器材面對的是穩定的600歐牛初級，而後面的也是接受穩定的600 歐輸入。越不匹配的器材有可能受益最大。更可以幫助驅動長的訊號線。

牛還有壹個同樣重要的特點。它可以過濾很多不必要，甚至危險的東西。各種失真（很多耳朵聽不到，但會影響音質），以至直流。好的牛，如優美，會讓人覺得背景甯靜了，聲音純真度高了，就是這個原因。

音頻牛的運用

音頻牛有這麽多潛在的好處，爲什麽我們很少在器材上見到？原因很簡單，成本太貴了。牛的制造不容易，全世界沒有多少個用家能自家生産（優美是例外，本身主要做各種牛的）。音頻牛雖然小（優美的罩在那兩個圓罩裏) 但它的制作不會比大許多的輸出牛容易。通過的訊號非常小，品控就更加重要。牛的制造不光是科學和手藝，和任何音響産品壹樣，還是含有人耳調控的成分，人耳的取舍和決定。研發的代價不少，在國外會是非常貴的。這不只是錢的問題，設計師遇到阻礙時肯定會抓狂 （廣語“嘔血”），只有最有耐力的人才可堅持下來。

現在世界上沒有多少人生産音頻牛。它大部分功能可以用其它零件解決。可是幾十年前就不壹樣。回到西電年代，非常多的器材其實是專業（如戲院）用的。幾乎所有器材都會有音頻牛，有些有增益（麥克風放大），有些沒有。那時候專業已經用平衡端子，去到膽機要用牛轉換成非平衡RCA。牛也可以輕易倒相 （優美就可以）。

既然現代零件可以代替音頻牛的功能，它有存在價值嗎？在音響領域裏，肯定有！西電用家再清楚不過。那些拆下來的”過氣“西電音頻牛現在價值連城，有錢都買不到！爲什麽？就是因爲它們能做到就算發燒級零件都做不到的效果。比較普遍的西電 111C大家可能比較熟悉，二，三十年前發燒友壹窩蜂地把它接在CD機後面。現在，更貴更罕有的91A已被搶到價錢不斷上升。

多重用途示意圖

留意: 點擊鏈接首先看到的圖片是比較便宜的 1:3, 不是這裏說的 1:1

必須挑對的"顔色"，有銀黑二款

Overview Sun Audio VT25 300B Philips AK601

Click pics to enlarge. Top, 300B amp built using Sun Audio VT25 kit with minor mods (see text below). The WE 274B and 300Bs are worth much more than the amp!!!!

Overview: Sun Audio

Glory: Western Electric
Letter from Hong Kong (24-1): Sleepless Night in HK

These days I go to Hong Kong to run errands perhaps every one or two weeks. To avoid crowds, I’d be on the Metro by 6:30 and be in HK around 8:30. I’d go for an early dim sum breakfast, then attend to things and return to Shenzhen well before the evening rush hour. I had largely avoided the Rush Hour all my life and that won’t change.

Last Wednesday, when 17 of us old Wah Yan Kowloon boys (Class of ‘72) gathered at the Cragengower Cricket Club (CCC) for dinner. This marked the first time I had dinner in Hong Kong in three years. Food was very good but even better were the wine brought over by two of the boys. I particularly enjoyed the Talbot Saint Julien (Second Growth).

Too late to go back to Shenzhen, so I got back to my old house around 11 pm and promptly fired up my SET amps. I went back and forth between my Sun Audio VT-25, my Sun Audio 300B (“mismatched” 5K transformers, using the VT-25 kit) and the Elekit 2A3 (TU-8230). I rummaged through my many boxes and dug out some precious tubes. Source was a lowest of the low end Philips AK-601 CDP. Preamp was the Melos 222 and loudspeakers the Ruark Crusader II.

Click pics to enlarge. Above, Station B Last Time. Center, Philips AK601 CDP and Melos 222 Preamp below Sun Audio VT25 and DIY 45 amps. Left, from top, Micromega Duo transport, Micromega Solo, Elekit 8230 2A3 amp, Philips cheapo CDP, Micromega Duo Pro DAC, PS of Melos 222 and Bryston 4B. To the right, note the Ruark Crusader II in front of the B&W Matrix 801 Mk II. Note the "wall" on the right side was a partition using steel cabinets. Note the Tile Floor.

I had written a little about the great sound of this Station B when I went back to the house last time (pic above, article here). Yet on this night the sound was even better, indeed exceptionally good; in fact, better than ever probably, and that goes back more than 20 years.  Yes, only flea power was on hand; yes, it was late and I was not listening very loud. But it was simply magical. As I wallowed in the splendor of the Triode, I asked why. I don’t have answers, but let me talk more first about some of the amps and tubes.

Overview: Sun Audio

I probably know more about Sun Audio than most people out there. I thank Hong Kong's Reference Audio for that. More than 20-25 years ago, they sold tons of Sun Audio kits in HK, at irresistible prices (like 1000 USD, including tubes). Many of my friends (like Hoi and I) bought more than one. They are fantastically finished, have a small footprint, easy to build and service and, most importantly, sound just fabulous. I know about all their models, and have heard most of them, and they haven't changed at all. I have myself (and helped others) converted some of them (like to 45). I have even met the father and son (here in my Guide to Akihabara). Unjustly, Sun Audio is not well known (or available) in the US, and that's just too bad. If you ask me, their amps sound better than those of most competitors. As the price of kits like Elekit has escalated to (for me) unreasonable level, I'd think Sun Audio offers a much better bang for the money. More below. The most iconic Sun Audio Amp is the 2A3. Indeed the basic circuit is there, and everything else are variants. Here is a bit of what I wrote in my DIY article:

• Example - Sun Audio 2A3/300B amplifier Back a decade ago, through my yahoo forum, I must have played a role in the popularization of Sun Audio kits, particularly in HK. I must say I have never met a Sun user who doesn't like his amp. But in the forum, where there are a lot of DIY people, including some well known figures, the very simple design did meet with various criticisms. Some of the people built kits by another kit maker (say kit B) and made every conceivable upgrades recommended by a respected electronic guru. A friend had a fully decked out kit B that used all manners of chokes and it went up against my Sun Audio. I personally feel, despite the simplicity, the Sun more than held its own. If not for my awkward position I'd call the Sun the outright winner. I wanted to support kit maker B and so did not really fully air my opinion. And what do I know about circuits to argue with the guru, who I also happen to like? As much as I respect electronic know-how, the experience taught me to keep an open ear, to say the least! My convictions were further strengthened when, over many years, I heard many decked out and not inexpensive DIY amps went up against the Sun amps. I am sorry to tell you all of them did not sound as musical. Now, I know fully well the Sun amps are not the ultimate in anything, and they are not cost-no-object designs to begin with, but they have continued to hold up amazingly well over the years. The designer had used his ears well and balanced things deftly to make simple yet engaging statements, thereby trumping much DIY grandiosity in the process. That is something called "art", which the majority of DIY people fail to understand.

That rings even more true today. In fact the electronic guru I mentioned had gone on to design for major companies. But my position holds. I'd think Sun Audio can compete with the best of them. The Wavac's (MD-300B and higher end EC) surely have more poise and drive, and the Verdier is no slouch, but the Sun Audio keeps up. What I'd love is to size up the Chinese APPL with this Gold Standard!

2A3 This is the foundation of Sun Audio. The output transformer has 2.5 and 3.5 ohm taps. This kit can be easily converted to use SE pentodes, tetrodes (even 45, my fav), etc. The 2A3 amp has long secured its place as the best. Not much can touch it. Second hand units trade quickly and price remains firm.

300B (LE) This is just a variant of the 2A3, using some simple mods for filament of 300B. Sound is under-rated. Very good, if you ask me. I used to have one of these (not the one I have now using mismatched VT25 kit) and imho it killed most of the competitors.

VT25 This one has a transformer that has 5K and 8K taps. The 8K is used for the VT25/10, and likely can also take the VT62/801A. Power rating is meager but it actually works quite well! My friend used it well to drive his Tannoy Black (here). For my experience see below.

Push Pull Amps Despite Gizmo's enthusiasm I don't like these. Totally dismissible compared with vintage. 

Preamps They seem rather simple. Never heard them.

As you can see from the above, I vouch for their SE amps, but not the rest.

Resource It's pretty amazing that Reference Audio has continued to sell Sun Audio products after almost 30 years! In fact their bilingual official website now is very informative of Sun Audio stuff. I direct you to the Sun 2A3 and you can go on there to view all other Sun models! Mind you, I think that's all fine with HK readers, but I don't think Reference Audio is authorized to sell US 120V products.

Listening Notes 

• Sun Audio VT25 Last time I listened to the thoriated RCA VT-25 and the formidable WE 274B and it was wonderful. This time, I listened to the WE VT-25 with the (lesser)WE 422A rectifier, and I think it was even better, mesmerizingly subtle and refined. No matter how you tube it, this is a fabulous amp that belies its ultra-low wattage (rated 1.3 watts, probably lower) if your loudspeaker is sensitive enough. I note that I can probably also use (thoriated) VT62/801A, and may try it next time.

• Sun Audio 300B This time (see top pic) I gave it the royal WE treatment and, boy oh boy! The beauty is beyond words. The very subtle articulation surpasses even that of the VT-25, though the latter was a little more yang. It made Until the End of the World, an album that I have listened to umpteenth time, sound like a new album. The pulse was sheerly riveting! Paradigm of Rhythm and Pace (PRaT)!

• Elekit 2A3 (TU-8230) After all that, the Elekit could only came in a distant third, even with old-stock Single Plate 2A3. BUT, it still has that subtle articulation that I like even without WE tubes. Which leads me to...

• Philips AK601 CDP As a basic sonic signature was retained whether WE was in the chain or not, I must credit this very humble CDP for the great sound on offer! This is an ultra low end CDP using CDM4 transport and 16-bit TDA-1543 with 4x Oversampling. And it has a captured generic red-white interconnect (I will upgrade it in due time). Regular readers will know I love the sound of this type of CDP (for a start, see this article).

• vs Shenzhen In a link earlier in the article, I made no bones that my HK setup is superior in sound to my SZ setup. The room, the equipment, they all make a difference. But I still am happy with the sound of my current SZ setup, which will be updated in a coming article (some new players).

I was so intoxicated by the sound that I listened till 3 am. Sleepless night indeed!

Schematic of Sun Audio VT-25 amp (from Reference Audio)

View from the Government Education Bureau in Kowloon Tong.

The right-most hill is the symbol of HK, the Lion Rock  

Kowloon Wah Yan, a Jesuit School

肉丝炒面，深水埗 大利

HK Staple, so-called Singapore Noodles！

Happy New Year Goalbon Audio Grado SR80E

Click pics to enlarge. At Goalbon, I listened to the Zingali Bookshelves driven by the EL34 integrated amp (under the black Mimetism CDP on front rack). Flanking the Zingali's are Italian Casta Loudspeakers. Rear, EL34 monoblocks; in center top are the 2-chassis Preamp and besopke TT; beneath the latter phonoamp. Front, on the floor is a headphone amp sporting 2A3, 12AX7 and 5687.

Letter from Shenzhen (24-1): Happy New Year
A Visit to Goalbon Audio

Kudos Grado SR-80E

12/31, 4pm I started writing this on the last day of 2023. I was happily ensconced in my SZ home and was home alone! At 4 pm (remember we’re 12 hours ahead of EST USA), I opened a bottle of Bordeaux and started writing. Not even sure what to write when I picked up my pen (so to speak)! You can call this kinda train-of-thought, real-time writing, kinda in the manner of real-time filming, like in the Chantal Ackerman classic, Jeanne Dielman, 23, Quai du Commerce, 1080 Bruxelles (recently voted as best film ever here). Of course, that film took more planning than you can imagine! And it brought back my youth - I watched it in one of NYC’s then Revival Houses and, as I wrote I recalled certain scenes vividly. In case you don’t know yet, I’ve been a life-long film buff, my preference being closely observed dramas, no matter how small (which is why I have a predilection for European [including the UK], and esoteric films [from all continents], and disdain Hollywood). Perhaps, as an audiophile, I should call it Single-Ended (SE) drama, which shakes and moves only within a small but, to some, all-encompassing envelope. The world panders largely to those who watch Marvels and blockbusters; in audio terms, it’s like all those humongous and often wrongfully deployed and distasteful huge amplifiers (ss or tube) trying to blast us into submission with lousy inefficient loudspeakers (but audio is worse, usuallycompletely devoid of humor). Make no mistake, I can enjoy a Marvel film but I do know they are broad-stroke caricatures of life. The important question is, do you?

12/30 5 pm Perhaps the best way to capture some of the sentiments I feel is to recount the day before, Dec 30th. I was to attend a so-called New Year’s Concert in faraway Guangming, and Goalbon Audio 高班音响 headquarters (Official Website) sits sort of half-way, so I decided to pay them a visit. I had met them during the SZ Show earlier in the year, and even though I had notified them last-minute, they were accommodating.

The small showroom is very comfortable. The very charming Miss Gao, and the forthright Mr Ding put me at ease. A certain very nice Mr Chen was also there. I just listened to the Zingali bookshelf loudspeaker being driven by Goalbon’s “entry level” EL34 PP amp. Source was a French Mimetism CDP and sound was decent. In particular, Aaron Neville showed good detail, articulation and good bass texture.

We drank tea and time flew by. I then realized that I had to go, and scrambled towards my concert. As chronicled in my classical blog, I had some setbacks, but the transcendent performances of the Russian Orchestra made it all worthwhile.

12/31 9 pm Still typing away. All of a sudden, I discovered (via wechat) that the Chengdu Symphony Orchestra had a New Year Concert on line! I tuned in midway and it was Beethoven 9th, conducted by their director Chen Lin 音乐总监陈琳女士! I didn't even bother to have it on my regular system. Instead I plugged my trusty Grado SR-80E headphones into my iPhone 6. Yes, that old a phone, but sound was astonishingly good! I tell you, for people like me, that's all the headphone I need (I do have some high impedance cans like Sennheiser 600). The presence factor was just superb through the budget Grado. I also like chatting with friends on wechat while we watch the concert! Of course, with a drink too! It was marvelous! It made my evening!

1/1, 2024 6 pm Now I'm winding up this article. This I call as one of my best Year-End ever! In the coming year I shall revisit Goalbon to give a more detailed report.

Below New Year's Lunch at Friend's