I used to be listening by way of probably the most compelling sound system I had assembled since I began writing for Stereophile. The dCS Bartók DAC/streamer was funneling the harmonic purity and hypnomagik of Odile Renault on flute and Elodie Reibaud on harp into HoloAudio’s appropriately named Serene preamp, which was feeding Elekit’s TU-8900 300B/2A3 package amplifier, which was sending a couple of of its triode-tube watts to the TAD’s $32,500/pair Compact Evolution One screens, extra compactly generally known as the TAD CE1TX. I reviewed these three-way standmount audio system final month, discovering them to be probably the most thrilling, accurate-sounding, well-engineered audio system I’ve encountered.
What was distinctive about this technique was not the way it sounded however how simply it enabled various types of music to summon reverie and have an effect on my mind-setthe way it made rhythms linger in my head after the music stopped.
My overview was completed, and I knew the TADs had been leaving tomorrow, so I figured that day can be greatest spent bathing within the utterly loopy fantasticness of an 8W, comparatively cheap, made-in-Japan package amp (!) driving a 4 ohm, 85dB-sensitive, also-made-in-Japan field speaker of the best pedigree.
Effectively-recorded compositions for flute and harp depart no place for dry-sounding suggestions amps or dull-sounding field audio system to cover. Each devices’ harmonics should be absolutely uncovered. For these high-energy devices to have a touchable vibratory presence, a system’s higher octaves should be information-rich, pure, prolonged, and harmonically full. One way or the other, on that day, that Elekit-TAD combo was doing what felt like an ideal job of being pure and harmonically full.
The above-described pleasures weren’t, I imagine, only a fortunate consequence of an opportunity pairing of Elekit’s new (in 2022) TU-8900 300B/2A3 amplifier with an costly three-way field speaker. There was extra occurring. What really occurred, I imagine, was that the CE1TX’s easy-to-drive, extremely descriptive nature responded very properly to the flood of small knowledge issued by an amplifier pumped up on three sources of information-preserving steroids: Lundahl’s made-in-Sweden LL2785C AM amorphous-core output transformers and Audio Be aware UK’s tantalum resistors and silver-foil coupling capacitors.
The North American model of the TU-8900 package has been closely parts-curated by the frugal, artistic thoughts of Elekit’s Vancouver-based distributor, Victor Kung of VK Music (footnote 2). The result’s a package amp with the identical high quality of elements as most of the world’s best and most costly triode amplifiers. I’ve a globally revered Euro-friend who builds customized 300B amplifiers on fee, price no object, deep into 5 figures, and he is utilizing the identical stage of Lundahl output transformers because the $1945 TU-8900 (beneath). The $15,000 Shindo Laboratories Cortese 300B amplifier makes use of them, too.
My TU-8900 package got here preassembled (a $375 possibility) with a transparent acrylic prime plate that enables me to admire the conspicuous legion of Kemet stable polymer aluminum capacitors (footnote 2) and the 2 giant, symmetrically positioned Audio Be aware 0.1µF silver-foil coupling capacitors. These are Audio Be aware UK’s highest-quality capacitors, a step up from the superb copper-foil caps used within the $19,300 Audio Be aware Meishu reviewed by Ken Micallef in January’s Stereophile. VK Music sells Audio Be aware’s silver-foil coupling caps for $355 every. The Audio Be aware tantalum-resistor possibility replaces all 46 resistors within the sign path, two Amtrans AMRG resistors, and 4 Takman carbon resistors for $265. My TU-8900 got here with the complete Audio Be aware Silver improve, which prices $960 and contains all of that plus two acrylic brackets for securing the big silver capacitors.
The clear prime plate, which is included in the price of meeting (and a $35 possibility with the package), turns an atypical, classically styled tube amplifier right into a dramatically visible, sci-fiwanting little bit of audio structure, one which manages to look futuristic and understated on the similar time.
Along with the Chernobyl-red LED gentle flooding out from the ability provide modules stationed beneath the transformers and the orange glow of the Venus tubes protruding from the clear deck, vivid twin LEDs flank and backlight the amount management at heart entrance. These comparatively giant, symmetrically positioned bulbs glow inexperienced on startup as sensors measure heater present to find out whether or not the ability tubes put in are 2A3s, during which case the LEDs keep vivid inexperienced, or 300Bs, during which case they flip blue.
With the abovementioned choices, my TU-8900 prices $3280 with out tubes. Selecting a start-up tube set is the place many Elekit prospects start their tube-rolling journey.
The Elekit’s 4 tube-set choices start at $365, for 2 Cossor/LinLai Delux 2A3s and two Sylvania 12BH7As, and prime out at $1525 with a matched pair of Western Electrical WE300Bs (with a 5-year guarantee) and two US-manufactured Sylvania 12BH7As. My overview pattern got here with one of many center choices: two Cossor/LinLai WE300Bs and two made-in-England Brimar 6087/12BH7s for $625.
Altogether, this makes my TU-8900 a $3905 stereo built-in amplifier specified to output 8Wpc with 300Bs. With 2A3 tubes, it’s specified to output 3.5Wpc. Each specs are at 10% THD.
Each single-ended tube amplifier, irrespective of how a lot it prices, begins with a easy one- or two-stage voltage-amplifier/driver circuit, which is normally one among a number of outdated warhorse circuits executed anew, with possibly a rectifying or tube-biasing twist and a few modern upmarket elements. Or it may be an outdated warhorse with premium bits tweaked as much as one thing much more lucid and authoritative by the addition of premium-quality transformers, just like the TU-8900 I am describing right here.
The 2-tube, three-stage circuit within the TU-8900, which was designed by Yoshitsugu Fujita, is a variation on a time-honored traditional that each DIY tube individual has encountered in schematic type. The TU-8900’s circuit differs from that of the TU-8600, which I reviewed in Gramophone Desires #27, in that the ‘8900 eliminates the high-gain 12AX7 voltage-amplifier stage. Within the TU-8600, one part of a 12AX7 dual-triode is capacitor-coupled to a paralleled 12AU7 twin triode, which in flip is capacitor-coupled to the grid of the 300B. As a result of the TU-8600 applies cathode suggestions to the 300B circuit, it requires the extra drive of a paralleled 12AU7 and the extra acquire of the 12AX7.
As a result of the TU-8900 doesn’t use cathode suggestions, it makes use of a distinct traditional circuit, during which one part of a 12AU7 medium-mu triode is direct-coupled to the opposite part, which in flip is capacitor coupled to the grid of the 300B. That becoming a member of is the place the costly Audio Be aware silver-foil cap is used.
On the primary circuit board, beside the left channel’s blue-green LED, is a jumper that enables customers so as to add or take away the TU-8900’s 8dB of detrimental suggestions to be able to add or subtract acquire and adjusting the sound character of the amplifier.
Additionally hidden behind the simply removeable entrance panel are two rectangular jumper-equipped bays that let customers to regulate the amplifier’s acquire and output impedance of the ¼” headphone output to match a variety of headphones.
Listening
For some time after the TADs left, I used to be disturbed by how compressed and clock-radio small my Falcon Gold Badges appeared compared. The Falcons put out an expansive soundspace however with no weighty presence or crisp particulars within the shadows as there was with the TADs. To their eternal credit score, the Falcons remained unsurpassed in tone truthfulness.
I would been fortunately utilizing the Elekit TU-8900 for not less than 5 months and by no means as soon as thought to disconnect that 8dB of suggestionstill the TADs left. It is possible that the CE1TXs labored in addition to they did with this amplifier as a result of the suggestions barely raised the damping issue. However after two days again with my LS3/5as, I bought the discontented urge to vary one thing, so I disabled the Elekit’s suggestions.
I assumed that the impact of eliminating the Elekit’s world suggestions can be delicate; as a substitute it was apparent: A tense haze of grain and texture disappeared, changed by a darker however extra relaxed and vibrant presentation. I instantly bought the sense that I used to be listening to a rawer, much less filtered model of recordings.
Ever since I met Victor Kong and found the Elekit model, at AXPONA 2018, I have been utilizing a model of the TU-8600, first the TU-8600R, then the TU-8600S (with higher-nickel Lundahl outputs). Each of these amps delivered an interesting SET sound that emphasised what I thought-about the correct quantity of 300B tube readability and illumination. Whereas I not often paused to note it, the TU-8600’s naturally vivid demeanor was accompanied by a faint, misty grain I assumed was attributable to the electromagnetic impression of its stable state rectifiers.
I seen a few of this grain within the TU-8900 with suggestions, nevertheless it was overwhelmed by the dramatic 3D vibrancy generated by the ‘8900’s amorphous-core outputs. This enhanced vitality was so pronounced that I generally felt it was an excessive amount ofthat the amp was bamboozling me, making recordings sound higher than they really do, or ought to.
Then it hit me: What I used to be experiencingthe factor that was so dramatically completely different than the sound I had gotten used to with the TU-8600swas most likely the impact of the TU-8900’s new circuit with no cathode suggestions. Effectively, partly that. Extra doubtless, it was that mixed with these amorphous cores, the silver-foil capacitors, and the top-quality resistors.
It is vital to notice that these amplifier-circuit components, which aren’t free, don’t improve the TU-8900’s character. Greatest I can inform, what they do is remove materials contaminants and time-domain disturbances that stop the weaker elements of the uncooked sign from getting by way of.
After listening for months with Victor Kung’s parts-curated TU-8900, I can state with conviction that this package delivered the nuance, depth, and dramatic transparency of big-name 300B amplifiers costing many instances its worth. My long-serving, much-beloved TU-8600S doesn’t attain these heights.
Footnote 1: EleKit, EK Japan Co., Ltd., Tofuro-minami 2-19-30, Dazaifu-city, Fukuoka, 818-0105, Japan. Tel: (81) 92-923-8235. Internet: elekit.co.jp. North American importer: VK Music, Vancouver, British Columbia, Canada. Tel: (604) 931-8844. Internet: vkmusic.ca.
Footnote 2: See content material.kemet.com/datasheets/KEM_A4072_A759.pdf.
