Tube Kingdom, Vol. 97【Tube Kingdom, Vol. 97】

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Tube Kingdom, Vol. 97

211 Single Monaural
Refurbished after an interval of 20 years, high-wattage 211 single amplifier,ATM-2211J.
Sounds are full of energy and have outstanding presence.
Reproduction of sounds is faithful to reality and leaves exquisite impressions.
Experiencing the crystal clear world of vacuum tube amplifiers through alistening trial of one among 18 of this kind of single amplifiers.

Iori Yoshida: After launching its 15th anniversary model, the ATM-211, ATM
refurbished the model about 20 years later and released the ATM-2211J, asingle monaural amplifier incorporating the transmitting tubes of the ATM-211.
The 211 tube is a large-size direct heated triode with superb linearity, requiring ahigh plate voltage of 1000 V. The upper stage consists of a 12AX7 tube and a
12BH7 tube. The output tubes utilize a direct coupled cathode follower/driver.
The application of NFB from the output tube plate to the 12AX7 tube on the firststage is a characteristic of the model. For its output transformer, ATM has newly
employed one made by Hashimoto Electric Co., Ltd. As for the powertransformers, the model utilizes two separate ones: one for the B power supply
and another for the rest. Its bias current check meter swings vertically and is2 / 7

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easy to read, and it is easy to replace the output tubes. The standard output tube
is a 211 tube by PSVANE, which has an output of 32 W.
Osamu Takatsu: Its sounds are full of energy and powerful with outstanding
presence. Listening to the vocals of jazz singer Sinne Eeg, it gave me a large
sound image, allowing me to truly get a sense of a vocalist with a great breathing
capacity. As for the band’s performance, you can enjoy the exceptionalheaviness of the bass sounds. The sounds of the piano are also stable, with afocus on the bass range, which bolsters its presence.
Yoshida: It is full of energy. Its dynamic range is huge. From the bass range tothe treble range, each sound clearly stands out, pops out. Listening to theperformance of Sinne Eeg and band, the powerful bass sounds pour forth
reminiscent of the Big Band sound. The bass range has resilience and is supple.
The good quality of the 211 tube is fully utilized by material superiority and thisshows in its sounds. The vocal is stately and strong and sings through to the end
on a grand scale. Though it does not capture Scandinavian lyricism and does
not push monolog singing to the front, it certainly expresses the melancholy andgloomy quality of the vocals.
Takatsu: When listening to Astor Piazzolla, it was totally different from otheramplifiers, as panoramic views were made manifest on a grand scale. It’s apleasure to see a story being shaped by sounds evolving along a timeline andthe experience is totally different from that of small-scale amplifiers. Its
representation is so powerful that I was drawn into it.

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Yoshida: The sounds produced by the bow on the contrabass are fully
developed, and I could feel its depth. The echoes of the sounds act in concertand I could fully enjoy the beauty of the live performance. Improvised sounds allcome together to the rhythm created by the cello and contrabass, and it wasboth clear and thrilling. The long downward portamento of the violin is vivid andthe notes of the bandonion are high-pitched but at ease, resonating throughoutwith dignity like a heavy tank. It gives the highest level of presentation, leaving astrong and realistic image.

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Takatsu: Listening to the Dumky trio by Antonín Dvořák, the expression isgentle yet full of energy, like that produced by a high-power amplifier. The
chords of the piano are rich. Though the touch is too strong, and the fade out isslightly monotonous, the crispness and the depth of its sounds are sufficiently
attractive, and play to its characteristics as a single amplifier.
Yoshida: Its scale is stately and it represents the high-tension tones of strings
well as they reverberate with each other. The notes of the piano are gentle, andthe harmonic overtone structure and texture are sufficiently presented. The
characteristics of the high vacuum direct heat 211 tube are expressed out front.
However, sometimes I felt that the distinction between slight changes in thetimbre and touch needed to be a bit more defined.
Takatsu: Listening to Mozart, you can feel the scale of the orchestra and it ismost attractive. In the chase by the duo, the violin sounded bright and easygoing.
Conversely, the viola sounded slightly somber. As a reference for the listening
trial, we changed the output tube to a vintage tube, the GE 211. This totallychanged the atmosphere. This is something that is very interesting with a single
amplifier. At first I thought that the sound of this amplifier was rather strong andhad a great presence. However, with the GE 211, a smooth and flexible touch
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was added to the sound. The sense of color produced by the violin and the viola
became well balanced and I was surprised that I was able to experience aprofound expression.
Yoshida: The introduction of the orchestra is stately and propelled to theforefront. Due to the integration of the whole tone, when the sounds of two horns
overlap the sounds are clear, proving that the amplifier has excellent analyticalqualities. The difference between the sounds of the violin and the viola is also
well presented. Since it uses direct heated triodes, the amount of flexibility in thetone quality could be better, but the sound is relaxing and I could feel its scale. I
enjoyed a pleasant sensation, feeling the elegance of the rococo music
throughout my body. When listening with the GE 211, I could feel thegracefulness and pliability of the sounds. The chase of the duo is glamorous andrelaxing. The slightly slow-tempo sounds of the viola are stylish and its execution
is superb. If you have various 211 tubes, you should be able to enjoy thedifferences in the characteristics of these tubes.
【Explanation of the circuit】
Airtight’s ultimate 211 amplifier might be the ATM3211; however, it uses apush-pull configuration. To replace its conventional single output amplifier, theATM211, the company released the ATM-2211J as a new top-level amplifier,fully renewed. With a high-voltage operation of 1000 V, its output is 32 W. Its
design is powerful, returning a strong NFB from the output tube plate to the firststage through multi-staged direct circuits. With a large power supply, like amuscle car, the ATM-2211J is a distinctive product that has dignified,satisfactory sounds. (Takatsu)
211 PSVANE, AIRTIGHT logo
211/VT4C GE
InsideRear panel:Speaker output terminals are 4 Ω (low) and 8 Ω (high). Input switch for RCA/XLR(unbalanced) on the rear panel.

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Power Amplifier Air Tight ATM2211J, 2,200,000 yen (pair)●Output: 32 W ●Input terminal: two lines (RCA unbalanced, XLR) ●Input
sensitivity/impedance: 500 mV/100 kΩ ●Speaker output terminal: 4 Ω (low), 8 Ω(high) ●Vacuum tubes: 12AX7 (Electro Harmonix, AIRTIGHT logo) × 1, 12BH7(Electro Harmonix, AIRTIGHT logo) × 1, 211 (PSVANE, AIRTIGHT logo) × 1●Dimension/weight: W 400 × H 255 × D 355 mm / approx. 25.5 kg ●Contact:A&M Limited; Phone: 072 (678) 0064
【Credit】
Tube Kingdom, Vol. 97, Summer 2020, published by Stereo Sound PublishingInc.

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