In practice, the A30 has one input less than the T9/T9 Pro, as the RCA analogue input and the coax cannot be used simultaneously. One of the RCA inputs is used for either coax or the analogue right channel. Never seen such an implementation before. Now I see what you mean. OK. The Aux Out on the T9 and the T9 speaker output are synchronously controlled by the T9 VOLUME: you turn up the volume and both the volume of your main loudspeaker and subwoofer output will go up accordingly. This has NOTHING to do with the subwoofer CROSSOVER. Or, put it this way. the Subwoofer Crossover ONLY adjusts the sub and has NO effect on the main loudpspeaker. You hear a difference but that is ALL from the subwoofer and your main loudspeaker is NOT changed at all under any circumstances. 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: Overall I love the retro look of the device (especially in a dark room) the tubes 'glow' and VU meter is great (though the meter isn't very sensitive - you have to play loud to see it moving).

The reason for this is: without the antenna, the BT will have a poor reception distance, likely 3 ft at most. This will cut off other connected devices. By holding your device close you can achieve re-connection. Strong output power and low frequency output: use amp IC TPA3250, each channel can output 100W(4Ω), match perfectly and easily to drive all 3-8Ω passive speakers, adds a low frequency output easy to connect active speakers and build 2.1 channel system, the bass effects is greatly enhanced.Finally I capitulated and connected the amp to the larger loudspeakers (still with the Mogami cables). I still don't understand the hate for EQs. I have few of them and it is hard to beat dialing in things the way I want to listen to them. In contrast to Round 1, this time I listened seriously for much longer, in the hope to find out more about the amp section. I think these amplifiers are great - they have allowed me to try and experiment with things - while leave my main system alone - and though I am going to sell my T9 (though I do like it) - I have an A07 which is fantastic paired with a reasonable DAC!!

Revised 10/6/22: some more design process, including meters, added. Even if you have read it, you may want to re-read. You can only in- or decrease bass and treble in the TONE mode (+/- 10db in 1db steps). If you do, the unit automatically switches to the TONE mode. Sadly, there is no full EQ to manipulate different frequencies. Up close, the menu display is clear, the layout simple and streamlined. While I agree there are usually much better dedicated DACS out there I would want some good improvements to the T9 pro in exchange for the sacrifice of a built-in DAC. I personally run the T9 PRO through Aux/RCA, through my Schiit Magni Heresy which serves as a preamp, which is plugged into my Focusrite Solo audio interface. Works flawlessly.

HiFi For Sale (Hong Kong only)

I have been building hifi systems since the sixties, and I fine it remarkable that this little amp performs so well. Strong output power and low frequency output: each channel can output 160W(4Ω), match perfectly and easily to drive all 3-8Ω passive speakers, adds a low frequency output easy to connect active speakers and build 2.1 channel system, the bass effects is greatly enhanced.

When I connect the carousel to a Sony STR-DH790, there were no issues. The DH790 shows the connectivity info on the readout of C20C2./OC44.1kHz. Sony read the following optical output specs to me: The very same amp can be found under a different brand (Douk Audio/Nobsound) with model name ST-01 or ST-01 Pro. This is not unusual with Chinese HiFi components and, frankly, it is something I don't really understand. Most of the time, when you try to ask for “who does what?”, you don't get precise answers. Perhaps the real manufacturer and designer isn't Aiyima nor Douk/Nobsound, but a third company, and then the unit is re-branded under different names. I've seen a Douk ST-01 inside and, apart from minor differences on the chipsets used, it is the same as the T9. A closer look at one of the motherboards (see pic) unveals the writing “SMART 01”, which reminds me of the model name ST-01. Hence, is Douk the real maker? We'll never know. It seems related to a high output level limitation as it hasn't happened on most optical feeds. An xbox 360 optical played smoothly without any "skips" Bookshelf vs Floorstander As they are part of the same AV system with the same tweeter, youwould 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. A: If you use a power supply other than the original standard, please replace the power supply before testing. Many power sources on the market have large interference coefficient of the text wave, which will cause a large current sound.Globally, this amp is surprising, since it offers many features at a ridiculously low price. The other two amps sound better, in my opinion, but cost much more and in one case (the Io), offer far less. The best sounding amp of this trio is the Rega Io, while the SA1 and the T9 are almost on a par. The SA1 is more precise, controlled and transparent, but the T9 is more forgiving on lesser recordings. Hence, it could be a better partner for low cost set-ups that play even lo-fi recordings or compressed music. 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. Because the BT antenna is mounted at a right angle and cannot be swung out, it's imperative that you mount the antenna first, before plugging in any other connections.

The VU meter and green dotted meter that responds to your music seems a bit insensitive. At first I wasn't sure if it was working properly, but they certainly do -- you just have to crank it up. Unfortunately at those volume levels I would probably piss off all my neighbors so at my normal listening levels they don't move a ton. This might not be Aiyima's problem though, since I do wonder if I used more high-quality, demanding speakers if it would then be more responsive at reasonable volumes. I also might be misunderstanding how they work, since it seems they respond to your overall volume and not just your input signal volume or volume on the amp itself. I'm unfamiliar with VU meters so I do wonder if this is just how VU meters work in general. Here's the list of TOS optical outputs I have so far. Xbox 360, ASUS z690 Apex Maximus, TCL Roku Television 2 Sony CD carosels, Android TV with HDMI and Optical output. While I was in HK, I had 2 locations. The "older location" was where my reference was. The "newer location" was where I spent most of my time from late 2012 to late 2018 (Last revised Nov 15, 2019). After being vastly criticized by several online reviewers/YouTubers, Aiyima has released a new version of the T9, called T9 Pro, which has solved this annoying issue. And while the designer was there, he completely changed the internal circuits as well: new input tubes (now JAN5725) and new chipsets. Have a look at the officially supplied chart below to detect all the differences. Even the power supply is different, since the T9 accepts also 32V now. Actually, it's a completely new amp.

Dexler Poppe's Choice: Lucrecia Dalt - ¡Ay!

The Aiyima had no problem driving both pair of speakers to a more than adequate listening level from my seating position (6 feet from the speakers) 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. 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). Though I don't feel like it's a "tubey" sounding amp, even for Chi-fi pre-stage/buffer only tube amp category.