Aiyima T9

Click all pics to enlarge. The subject of this review, Aiyima T9, stands out just as the Beautiful Lady stands out in the photo above. If anyone knows more about this photo, please let me know. I found it in a Chinese news magazine here, but there's nothing on it.

Review: Aiyima T9, Part I, Swiss Army Knife

Editor's Note 2/2/23: Readers may be interested in this Video of the Making of Aiyima T9 Pro. It shows in detail how an Aiyima product is made.

Addendum 10/16/22: Part II (including Tube Rolling and PS Upgrade) published.

Addendum 10/5/22: Visit to Aiyima Headquarters published.

Aiyima Official English Website (T9 Specs)
Aiyima Official Amazon Website (some useful user comments)

Editor: Regarding Length This article is very long (Covid Revenge Review?), as per my usual style when testing things I am interested in, especially things that can be used in multiple ways. Regular readers and experienced audiophiles will more likely find the many details along the way interesting. However, the vast majority of readers, usually referred here by a Google search, may want to skip here and there, or even just go to the end for Impressions, Comments and Thoughts. Regarding Organization In contrast to my usual ways, Music Used and my descriptions of the rights and wrongs will have a shaded box near the end, and there shall also be a little Technical Info near the end.

Preface Boys shall always be Boys (though better not be "Proud"), and we need toys. We are always itchy. But in my 1.5 years here in China, I had not bought a single item. Amazing, no? It's not surprising: I have so much good stuff both in NYC and HK that I simply could not use here, and I have always viewed my stay here as transitional. So whatever tempts me better be (relatively) cheap and cheerful.

Finally I have broken my abstinence, and I don't regret it. This review however turns out to be more difficult (in execution) than I thought (but highly worthwhile), primarily due to lack of arsenal here (I don't even have extra cables here). This is perversely interesting too, and some audiophiles may empathize ("I wish I had kept that..."; "damn, I need that gadget in my old house!"...). In fact, this review shall likely change my audio trajectory here a little. More on that later.

The Informant Although in China, I'm always in wechat contact with a few of my audio friends. Regular readers know of Icefox and ELO, our HK contributors. Unlike me, they are avid youtubers; ELO told me of this little gadget which rose to fame after a rave review on youtube (please google for yourself; I still haven't watched it, perhaps deliberately so; see also official youtube at the end of the article). There is otherwise little on the net, except on Amazon (link above), where some useful and surprisingly detailed user comments are available.

The Decision Yes, call me superficial. I immediately fell in love with the SEXY (VU) meter! But, unlike some of you, I'd not easily give in! :-) Certainly I have no need for another amp (or so I thought). While the almost universal digital connectivity appeals, what seals the deal for me was the AUX OUT. I wasn't sure whether it is Fixed or Variable, but as some users used it for subwoofer it should be a Variable out. It is, and more on this later.

The Order The company is actually in my "backyard", about an hour away by public transportation. I managed to email and call them (in Chinese), and the salesperson (I think named Ben) was very helpful. I inquired whether the units sold on Taobao here in China are the same as the ones exported (through Allied Express and their own Amazon store). Yes, they are. Mind you, in the case of Chinese products, sometimes those sold through distributors or dealers (especially in the West) can be different from those sold direct (of course in price too) even in parts (like in my case with Dared) and what's included (PS etc). But Aiyima, no matter where you buy it, is in its original form; just check whether there is a PS. The price here in Taobao China, especially around 618 (one of lesser Chinese Black Friday's) is cheaper than in HK, so I hit the button a week ago! Just shy of 24 hours, the thing was in my hand (though substantial, it is small enough so one would do). Great, typical Shenzhen efficiency! BTW, being a fan of Ridley Scott's cinematic masterpiece Blade Runner, I’d say if the upcoming sequel does not include an army of delivery people on electric vehicles running through town then it has failed in its futuristic vision.

The Package It came in a utilitarian box that is well cushioned, which should survive long distance shipping (but the tubes are just naked in slots that are too big; for long-distance I think they should be bubble-wrapped as any tube filament is delicate and prone to damage if knocked around).

The Hiccup Foolish me! Well, I was so smart as to not order the PS. Who needs another Switching PS? The official one is 24V, but I saw from the pic of the back that Power input says 18-30V, so I was sure that my 19V laptop supply would work. I asked and they said yes. But I forgot about the connector! I have 3 Laptop PS, and 2 simply would not insert. The 3rd (Dell, 19V 3.5A) would, but was loose, so I had to angle it and weigh it down to ensure it does not fall out (see pic; not exactly ideal and I don't advise you to do so). I have Linear PSs (with connector kits) in both NYC and HK, just not here in China! A bummer. Am thinking of one, though!

On-Off But hey, how do u turn this thing on? I finally remembered the remote (batteries AAA x 2, not included, but that may be a good thing as many Chinese gadgets come with lousy batteries that are short-lived and leaky) and turned it on. Actually the Volume Knob (digital; continuous 360 degrees, an anathema to us old timers) has many functions: a short push turns the unit on; more short pushes cycle through the Inputs (it remembers the last Input you used); a longer push turns the unit off. I didn't find that out until later; it's in the manual but I didn't read it - the print was painfully small. Right after Turn On, there is a Relay Kick; a little later, a second one, with a small bump in the meter (the second one is for the amp section, which has to wait for the tube to warm up to ensure there is no DC Offset)

The Supporting Players Now, this is important. What I have here in China are very humble (by my standards), based on a set of more than 15 years old Chinese Sansui AV system (yes, the Japanese sold the name to the Chinese company, which is now a home appliance company) which I parceled out for 2 systems (main one, System 1, in my study, where I write for you; and the much less used auxiliary System 2 in the LR) There are a few extras that I had brought over from HK long ago, the most important being Revox and Sony. The stuff I use are detailed in my previous articles (Current iteration here, with links to earlier config). After some work they sounded pretty good. After listening to the systems for years I thought I knew them well, but what happened told me it was not quite so.

Source As I'm a classical fan I mainly use my low-end Chromebook to stream Naxos Music Library (courtesy of NYPL; described here). Here in China, especially with Jazz and Pop, I augment with Kuwo (here) and sometimes Spotify (which requires VPN), streamed using my HP laptop running Windows (now 11). I never use my smartphones to stream. Let me remind you that I mostly stream now, but I do have some good CDs and a very good CDP (Sony), but that will not feature in Part I.

I had really thought the review will be quick and to-the-point, so I didn't really want to uproot my systems unduly. Events proved me wrong. And so, I have decided to tell you my journey in a compulsively chronological manner (I do this only with the best gears). I hope you don't lose patience.

ROUND 1 As Integrated Amp into Sansui Bookshelves (actually Rear AV loudspeakers)

I poached these from my System 2. This short session is basically just to check functions and wellness. Due to several comments about the relay kicking in and even strange noise etc, I played safe and hooked up the Aiyima to these expendables. No catastrophe. Aside from the 2 Safety Relay Kicks at Turn ON, cycling through the Inputs you'll hear 1 kick for each Input. Another when signal plays through the selected Input. This seems quite normal to me. To clarify, the relay kicks are soft, and within the device, not through the speakers. For me, it's nothing; mind you, when I use my laptops on my desk (hours a day) I actually sit between the loudspeakers and listen to them like large earphones and the T9 is right at my elbow. More on the Relay later.

For connection (see right pic), as I didn't want to break my main system connections, the only loudspeaker spare cable I had was the Mogami 3082. As the strands are too thick for the tiny binding posts, I had to build adapters using short and thin strips of generic loudspeaker cable and screw them and the Mogami's onto terminal blocks (see my article on this here). BTW, please note the satiny finish of the chassis - very classy!

Out of the box, everything was well. Sound was pretty good. I was impressed. I briefly determined that everything worked properly. As there seemed to be no issues, I was eager to move on from this ad hoc solution.

ROUND 2 As DAC/Preamp Out Through my Regular Floorstander System (System 1) 

THIS is a BIG JUMP. I used the exact same 3.5mm to RCA adaptor and MIT cable I use for my Meridian Explorer, through T9's AUX OUT. Of course, I removed the loudspeaker cables from T9's binding posts.

• The VU Meter The regular System goes through the Revox Preamp, which has its own volume control. What I usually do is set the Revox Preamp to a ballpark area, and set the laptop volume to around 70-80%. For classical music I usually don't have to do much adjustments. If I need to I just do it on the laptop. Now, how do I adjust the volume pot of the T9? Well, I am not sure what's the "right" way, but I did it this way. I maxed out the output on my laptops and used the T9 volume pot. I made sure the loudest passage did not go beyond +3 in the red. For classical albums, this is easily established. But if you listen to podcasts of songs with widely different recording levels you'd be busier. Note that this meter is like a McIntosh power amp's meter, as it assesses the amp's output as a whole. It is different from that on a professional preamp (or mixing console), such as the incomparable EAR 912 that I had previously (here). With the EAR, the meter gauges the incoming signal and would go into the red on those horrible over-hot CDs even when the volume knob is at zero. Not so here. You may be curious why I don't just connect the T9 to the Revox amp directly. Well, two reasons: this way, I can match it against the Meridian; and the Revox amp is harder to get to (may do that in Part II or even III).

• vs Meridian Explorer Now I am a great fan of Meridian and think highly of this musical little device (here). The difference is instantly audible. The Meridian seemed a little livelier and airier. The T9 seemed (the italics are deliberate because of a later finding; hang on) slightly darker and slightly slower, especially on pop material. It was highly listenable and I began listening to many familiar recordings. It became clear that the T9 is better in one respect. The T9 somehow brings out more of the background players. Whether it is the double bass or violins or amplified electronic keyboard, there is more texture and harmonics - the instrumental envelope just seems larger and better defined. I find myself repeatedly caught up by these little “background” details and sometimes they seem to steal the limelight from the soloist (vocalist or pianist or violinist). For an experienced audiophile, this is something that cannot necessarily be bought by money (too much garbage high end out there - the majority I’d say).
  

• USB vs Bluetooth For the USB connection, I used the supplied USB A to B cable. The difference is also instantly audible. They sounded more similar than different, but the BT seemed to have a little more air. I started to wonder about the supplied USB A-to-B cable (in Chinese they also call it the Printer Cable, as USB B is what many Printers employ) but, hey, the thing is not burned-in (more later). BTW, the T9 Bluetooth only pairs when you select it, which imho is a good thing (I usually turn off BT on all my devices and only turn on when I need to use it - there's already too much interference in our environment), but that means you have to select it before you pair with the device. Once selected it seems to be memorized - if you switch to another input and then switch back to BT, it will automatically reconnect (provided you haven't turned off the BT at the source).
  

• Tone Control In this configuration, particularly with the USB input, I dialed up the treble a couple of notches (it is indented and the feel is good) to give a little more air on top. It is very effective. No need for bass adjustment as my Floorstander has excellent bass (in both extension, weight and definition). Remember the tone controls are in the digital domain and are “in circuit”, so there is no reason not to use them. Think of them as kind of like dithering, but this is more effective imho (I don't usually like the Filter manipulations and actually harbor at least a little contempt for high end digital products that offer a few to choose from).
  

I got the feeling that this configuration sounds a bit like a tube system (including the feeling of being slighty slower), and I am a tube man! I was satisfied.

ROUND 3 Back to Integrated amp and Bookshelf (as in Round 1) 

In contrast to Round 1, this time I listened seriously for much longer, in the hope to find out more about the amp section.

• Bookshelf vs Floorstander As they are part of the same AV system with the same tweeter, you would expect them to sound similar, and I thought they did (see also Round 4). Of course, the bookshelf is not as extended on either end of the frequency spectrum.
  

• vs Round 2 There are at least two major differences. The First is that the feeling of mild darkness or slowness or a tube-like aura completely vanished. Yes, the T9 has normal dynamics and Rhythmic Finesse. Those perceptions are therefore at least partly attributable to the Revox system, but also partly possibly due to the complicated Gain Structure of Round 2 (more on Impressions, Comments and Thoughts). The Second nagged at me a little: as I played more tracks, some albums just did not meet my requirements (like the Piazzolla described in Music Used near the end), especially with the USB, even if the difference between USB and BT had narrowed a little. The gain in speed and sharpness was not enough to compensate for the loss in musicality. So, again, I had some doubts about the USB cable, and so I ordered two adapters (more below).
  

• Chromebook vs Windows I started to play some Jazz and Pop music, using the Kuwo App on my Windows laptop (many Apps do not have Chromebook versions; I am probably the only person in China using one; most Chinese don't even know about Chromebook). The sound was often a little disappointing, and not quite as good as the Chromebook (I confirmed this by playing some classical tracks that I had played before on the Chromebook). I thought I had noted this and remarked on it before, but I cannot find it.
  

Suffice to say the results were not perfect but using the whole amp was encouraging enough for me to push on to the next and important step. I could say more in this section but the thoughts are better spelled out in the next round below.

Note the "Triple Threat" Unitek USB cable (brown). Below it is an improvised folded paper spring clip to secure the loose fitting PS plug. To the right generic cable for hooking up to the electronic keyboard. To the left of the T9, the diminutive Meridian Explorer. Far left is the MIT cable and 3.5mm adaptor used in Round 2.

ROUND 4 As Integrated amp with Floorstander 

Finally I capitulated and connected the amp to the larger loudspeakers (still with the Mogami cables).

• vs Bookshelf Unlike in Round 3, I was shocked by how different they were! The Floorstander of course has more extension at both ends and dynamics, but I only then realized that the balance of the Bookshelf (AV Rear) is darker. In fact the system sounded just too sharp now and even gritty in the treble. After a few tracks, I decided something had to change.
  

• Loudspeaker Cable Swap (Sansui vs Mogami) I know from previous use that the Mogami 6802 can be lean in certain systems (as when it was tested in my System 2 in the Living Room; this is why it is a spare cable). My Revox amp is still wired to the Audioquest CV8 but I didn't want to dismantle it yet if other ways could be found. In desperation, I appropriated for use the generic Sansui Loudspeaker Cables from System 2, as I know they are warmer sounding. These have bananas which can insert into the T9. No more Terminal Block. YES! A success but not quite a Bull's Eye. It took a little time to settle in (haven't been used in a long time) and now at least I could sit down and enjoy music.
  

• vs Revox System Although the tonal balance was now restored to near normal, music played still lacked that last once of magic that the Revox system had provided in Round 2. I knew the Piazzolla could sound better still, but I was at least pretty satisfied. I went to the library to continue to write this article. Home is too distracting (ELO and I went back and forth on wechat with each finding). And the library has free air-conditioning). :-) I periodically checked my smartphone. Goodness, the USB adaptors had arrived in less than 24 hours! I couldn't wait to test my theory.
  

• Menage a Trois Unitek vs Stock I have long used Unitek USB cables (in China 优越者) and had written about them (here they beat the well regarded Belkin Gold and others). I still have a Unitek USB A-to-B in NYC, but here I only have the Unitek A-to-Mini (for the Meridian). Here on Taobao there are almost 20 kinds of USB adaptors, but not Mini Female-to B Male. So I ordered 2 hemaphrodites to make one: Mini Female-to-A Male, and A Female-to-B Male. The copulation is positively pornographic. But as soon as I switched to the Triple Threat Unitek, I knew my work was done! Yes, it's that incredible. Things just opened up and background instruments re-acquired their larger envelopes. More sweetness and subtle inflections. And yes, Piazzolla is back too! Now, it sounds very close to the Revox system in Round 2, but with faster transients and just a tad less "tubiness". Later, I found out the B version of my particular cable can be found on Tabao but in undesirable longer lengths (for printer use); I'm sure with more work I can find a 1 m one, but, unlike many of you, I hate scrolling on my Cell. I'm not even sure that's needed. Despite the Menage a Trois, the musicality seems intact. USB vs BT Finally, with the cable change, USB performance surpasses the BT (a little more detailed and textured), but it's commendable that the BT is very good. All of you probably have your own favorite USB cable, so I'm not worried here. Next round maybe I'll match it against ELO's Kyoeon H-9 (I have a feeling the Aiyima is better). In fact, I feel the Aiyima is worth the price even if it just has the BT.
  

• Line (RCA) In I tested this briefly with the Electronic Keyboard on my desk. Sound is good, but quite different than through the Revox system (cabling are different), more like a Bosendorfer to Revox's Steinway. Shall test it more usefully with my CDP in Part II or III (which can also test the Coaxial and Optical Digital Inputs with Red Book CD 16/44.1).
  

I am now completely satisfied with the Aiyima in my modified System 1 and am streaming with a smile. Everything is good and that little bit of tube sheen is highly desirable. I shall conclude Part I. In Part II I shall likely be using the T9 as Preamp in my Living Room System 2 (which is why I bought the T9 in the first place). For that I shall restore my original System 1, which would be a real test. The last A in ABA is always more important than the AB. Now for some tidying up:

Comments, Impressions and Thoughts

• Relays IMHO this issue is way over-blown. I stopped and restarted tracks (even counting to 10) to test this and the Relay never kicked. But, after a longer period, yes, the Relay will kick in periodically. Why is that a problem, I don't understand. Also, when the laptop (or your cell) crashes or needs to restart, the relay may kick in a few times as the USB or BT outputs stop and start. That's fair enough. For the great sound on offer, don't let this be a deal breaker. It's your loss.

• Tube (and Noise?) The tube is actually part of the good sound, as is most often the case. My own feeling is, this 6K4 tube, a new one to me, seems like a great sounding tube on its own (likely sweeter than the Chinese 6J1, 6N1 and 6N3). I may get some JAN 5654 for fun later (too bad my NOS 6AK5, including WE 403, are in NYC!) Mind you, none of these are exact equivalents, just pin compatible and similar. Electrically, they are a little different but used as a buffer the differences are likely unimportant. Think of tube swapping as potential fun, but with something like the T9, even the stock tube sounds mighty good, and quiet. Noise? There are worries about so-called noise. My unit is quiet as a mouse. From the description, I am pretty sure these were caused by faulty tubes. Most of the people who buy the T9 are not really seasoned audiophiles, and many probably encounter tubes for the first time. Now, one must make sure the pins are straight and orientation perfect before attempting insertion (2 of the pins are farther from each other on both the tube and tube socket, and perfect alignment and smooth insertion are a must. Even a little forcing can harm the pins (and crack the vacuum). Also, for these tubes that are small in diameter, the pins are more slender than usual, and they may rock a little even in socket. One of mine is a little looser. That's par for the course. Now, there are probably at least hundreds of T9s around (lots of them in inexperienced hands), and only occasional tube failures - that's a rate that is likely better than astronomically priced hi-end gears. If you read Stereophile (or TAS etc) you would have encountered quite a few reviews of hi-end stuff delayed or even marred by tube failures (and they don't sell that many). See, even with a tube tester (lower voltage than actual operation) and normal results, faults can still develop in use. Happened to every serious tube user. Don't let this deter you.

• Volume Control I must say I am not a fan of this kind of continuous rotation digital controls but they are part of the norm today. You never know where you are. The unit at first starts at rather low volume and sometimes you cannot even hear the music initially, but it then remembers your last volume choice if you are using the same Input.
  

• Comparisons with Similar Gears If I were in NYC, I'd have even more fun comparing the T9 to both my FX TUBE-01 (here) and SMSL Amp (here). And I'd have more tubes to play with. But, based on what I hear here, I am more than confident the Aiyima is at least comparable (if not better). I actually think the Aiyima is sweeter than both, especially the Preamp Out compared to the FX (even with better tubes).
  

• Comparisons with Other Integrated Amps Actually, this is in response to ELO's question. He asked me how does the T9 measure up to bigger and more expensive higher end products. A good question, as it can put the casual reader into perspective. Well, first, I am not impressed with the modern "hi-end" integrated amps. Those I have personally heard were from before the digital input age, before digital amps. I have heard plenty then, including Audionet, Burmester, Copland etc, and there was NONE that would make me trade in my NAD 3030 and Nait I or II (or 47 Labs; or MF A1, not that I still have most of them). In fact one of this blog's perennially most-read article is my integrated amp survey (here). And now, many hi-end makers are taking the digital route. Yes, I have unfortunately heard not so long ago the Goldmund digital amps and I think they are awful. My own feeling is, for a T-amp, Class D, digital whatever, I'd NEVER consider an expensive product. Cheap and cheerful is where I'd stay. Now, would I replace my NAD 3020 (large number of entries in this blog) with the T9? No, but I'd gladly use the T9 in lieu of the later 315BEE (here) or Micromega IA-60 (here) etc. Would I use the T9 instead of Nait I/II? No, but I'd gladly use it in lieu of Nait III (here) and beyond, and probably Cyrus I/II (I have not experienced the earliest plastic I). For many readers not into buying second-hand equipment, the ridiculously cheap T9 with its full connectivity is a no-brainer. Mind you, for the last 2 days (since the USB cable change) I have streamed many albums and I have no complaints at all - everything is in its right place.
  

• Comparisons with DACs and Preamps I think this is actually an even more relevant question. All these digital amps (including so-called high-end ones) probably sound more similar than different in their amp section (the more expensive deliver more and perhaps "cleaner" power, but that certainly does not necessarily mean better sound, especially if you are using more efficient loudspeakers). In truth, digital input probably also has advanced so much (on a broad basis) that it's likely equally difficult to tell the difference between high and low end. A single chip can do so much now it's really astonishing, and I think the T9 proves the case. In this Part I, I have basically assessed the Digital Performance against the humble but excellent (and more expensive) Meridian Explorer and mostly I think the digital decoding in T9 outperforms it. But I hesitate, because I shall later revert back to the original system, and that is often the truest test. Mind you, I hold my Revox combo high in esteem. Regardless, the T9 is astonishingly fine in its digital abilities.
  

• LoFi? Files Yes, I am streaming low-res files here through laptops. How does that justify the high end pretense (I have none; just in case that's your feeling)? Regarding low-res files I tell you: everyone is using it on their cellphones, including all reviewers, especially when they visit setups of others. And if the user has the same files in high-res at home, he would develop a correlation between the two and adjust mentally. In my case I have listened to many albums that I have on LP and CD through NML. In most cases, with a good system (such as my regular streaming systems in NYC and here in China) I don't feel short-changed and often hear things I have never heard before. The Gulda album is a case in point. I knew immediately if something didn't sound right (see below) and its beauties never stops to astound me. Devices Whether you stream on Smartphones or Laptops, the device has a sound and each is different. You should try them all and see which ones you like better. More below.

• The Gain Structure Most devices don't give out spec's on the sound output, or at least I have no idea what they are on my 2 laptops. Add to this that the Apps have their own Volumes (and EQ), and it's kind of complicated. You should always experiment with the Device Volume, App Volume and the Volume Control(s) of your equipment. This is why in Round 2 I'd not entirely attribute what I heard to the difference between the Revox and Aiyima. There are too many Gain Controls that one should be cautious. This is akin to some older preamps or integrated amps that have separate Gain and Volume Controls (ARC and MFA come to mind), and many experienced audiophile swear by using both. I assure you, for any final volume, the sonic difference between 1) maxing out the source and attenuating the amp; and 2) maxing out the amp and attenuating the source; is HUGE and beyond pale! Sonic advantages can be had by paying attention to these parameters. In Part I, I am not doing that.
  

• Power Input Aside from the less than snug fit, by using my 19V PS instead of the stock 24V, the Power Output is less. I asked Aiyima and they said maybe 10 Watts less. It is fine as is, but I think I'll get their 24V PS (or an LPS) in due time to bring it up to spec to complete the picture. As it is, the unit is quite warm to touch, but not very hot. Effect on the digital sections and tube should be small to minimal.
  

• Chips, Parts and Build Quality As an Amazon customer remarked, the Chassis is positively luxurious. The surface has a satiny and textured feel - classy! Parts used are good. The Chips are common and ubiquitous. A little on the heart of the machine, the Chinese 杰理 JL AC6926C chip - I suspect it's a great sounding chip (despite its relay quirks). On this, let me remind you that some of us think the big (and more complicated) brands (audio or chips) are not necessarily better sounding (remember ELO preferred his cheap Chinese device to iFi; rereading it I still want to salute him for his reporting integrity!). In any case, we only care about the result (mind you, we care about the sound and whether it is involving, as opposed to sites that basically just tests equipment on the bench and claim scientific ground, forgetting that the best science serves human needs, not vice versa). The T9 is simply damn good.

• HiFi Basics - Keep Trying, Keep Learning I think my journey illustrates that one should try out everything one has. In my case, I didn't have much choice. I probably think the Mogami 6802 is a better loudspeaker cable than the Sansui, but it is not suitable here. And if I were one of those "objectivists" I'd certainly frown upon using 2 USB adapters. But proof is in the pudding. We have too many preconceptions in audio and would do well to be more flexible. The experience also let me learn more about my equipment: I learned more about the difference between the 2 Sansui Loudspeaker siblings; I confirmed again my impressions of my Chromebook vs Windows Laptop; I likely have learned more about my Meridian and Revox (to be investigated further in the next round). The Transparency and versatility of the T9 enables all of that - for that it is a Swiss Army Knife of audio.
  

Music Used There were a lot. Some are old favorites, like La Spagna (BIS), La Folia (Harmonia Mundi). Some are albums that I have recently listened repeatedly to, like Bach Brandenburg Concertos by Il Gusto Barocco/Halubek (Berlin Classics), Beethoven Symphony No. 6 by Pittsburgh/Honeck (Reference Recordings). But for this round several other staples are particularly used by me for testing purposes.

• Astor Piazzolla The American Clave Recordings (Nonesuch) I used the first 2 tracks of this 3 disc set, where the Master's incomparable Quintet play. Tanguedia III has a sonically flawed and forceful opening that can easily sound congested and heavy footed. Only when the system is at its best (as with the original System I or the final setup of the Aiyima) does it sound more open and lighter on its feet. The Milonga del Angel is a slower piece that should sound sinuous.
  

• Mozart Piano Concerto No. 20 and 21 by Gulda and VPO/Abbado (DG). Now, NML has both: the one with the original cover and a a later twofer re-issue. Its shocking how much better the former sounds. The VPO should of course sound splendid with sweet strings. Gulda too is at his finest and the piano playing tests well a systems microdynamics. Tonally the piano should sound more like a Bosendorfer than Steinway.
  

• 
  Ruth Slenczynska My Life in Music (Decca) Amazingly beautiful music making by a 97 year-old. Track 2, Rachmaninov's Prelude, Op 32/5 is full of very subtle color shading. The track should sound mellow but not too mellow (lack of microdynamics). And then Track 5, Chopin Grand Valse Brilliante, is even more revealing. The slower tempo brings out much more color and rhythmic felicities - a tutorial on how to play and not rush the piano.
  

• In For One to Love, Cecile McClorin .Salvant sings an absolutely ravishing Le Mal de Vivre (original Barbara). She gives a completely new dimension to the song. The subtle use of inflections in her perfect French tests microdynamics.

• 中文歌我用几个专辑 陈慧娴 秋色 和 千千阙歌；罗大佑 爱人同志；陈永淘 阿淘的歌。都耳熟能详，差一点都不收货的。

Aiyima T9 Design At the heart of the T9 is the AC6926C Bluetooth chip, which besides BT conversion performs all control functions (volume, tone controls, selector and relay). Digital Inputs go through the MS8412. The 6K4 tube is basically a buffer (the Aux Out does go through it). Amplification functions are carried out by first the NE5532 and, of course TPA3221 chips.

Specs:
Replaceable tubes: 6J1, 6J2, GE5654, 6J3, 6J4, 6J5, 6Ж1п, 6AK5, etc.
Support: MP3/WMA/APE/FLAC/WAV
pc-usb sampling rate: 24bit96khz
Optical fiber/coaxial sampling rate: 24bit 192khz
Bluetooth sampling rate: 24bit 48khz
pc-usb support system: XP/W7/W8/W10/MAC/Linux (add my W11)
Total harmonic distortion: 0.07%
Signal to noise ratio: ≥98db
Frequency response: 20-20Khz (±1db)
Treble/bass adjustment range: ±6db
Speaker impedance: 3-8Ω
Output power: 100W*2 4Ω load

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