ATM-1

‘ATM-1 2024 Edition’ - Stereo Power Amplifier

ATM-1 embodies the culmination of AirTight's 38 years of challenges.

The ATM-1 2024 edition, (ATM-1E for short), is a model that carries on the name of AirTight's first product, the ATM-1, released 38 years ago. Utilizing a push-pull configuration of the classic EL-34, 38 years of experience and today's engineering technologies, Air Tight has created a completely new model.

After launch of the original “ATM-1” in 1986 and “ATM-1s” in 2006, the EL-34 push-pull amplifier” has been updated for the first time in 18 years as “ATM-1 (2024 edition)”. While following the orthodox yet sophisticated design of the original model and the concept of “a tool for listening to music”, we selected the best parts currently available and designed an amplifier that allows the EL-34 to provide more table performance.

Authentically designed to bring out the best of EL-34
The circuit configuration is a typical Leak-Mullard type. We choose to use UL connection from the balance between quality and output prospective to draw stably outputs of 35W+35W. We focused on authenticity over novelty, balance over uniqueness, and focused on bringing out the wonderful characteristics of the EL-34. The output transformer and choke coil are made by reliable Tamura. The bias circuit has a fixed bias, and a custom-made precision vertical edgewise meter has been adopted for ease of adjustment and ease of viewing and matching.

The input terminal is a single RCA system. The terminal can be changed to XLR Unbalanced Input (2nd pin HOT) by request. Speaker Terminals are sent to 4Ω/8Ω. The terminal can also be changed to have 16ohm by request. All components are carefully selected through sound checking, and carefully mounted and wired on pure copper sub-chassis by our experienced amp craftsmen. Traditional AirTight Chassis design
The appearance of “ATM-1 2024 edition” resembles the original ATM-1 design, but we have made modern updates and paid attention to every details throughout. The main chassis is a monocoque construction that combines strength and acoustic benefits. The exterior has been designed to prevent screw heads exposure, and a thick aluminum front panel is mounted as the face of the amplifier. The bottom plate is made of bright copper plated steel.

The amplifier is made to compact in size to appeal the slim modern EL-34 shape while feeling sense of weight and has a dignified sharpness, inheriting the "AirTightness" that has existed since the company's
founding..

Features:

• Stereo Power Amplifier
• Push Pull Design
• Input Selector (2-ch)
• Output Capability 60W handling
• Bias Adjustment Facilities
• CD-Direct Input

Specifications:

• Valves: 1/12AT7(ECC81), 2/6CG7 (6FQ7), 4/EL34
• Rated Output: 35W+35W (1kHz/THD<5%)
• Frequency Response: 20Hz~30kHz(-1dB/30W)
• Input Impedance: 100kΩ
• Input Sensitivity: 700mV(35W)
• Damping Factor: 6.7(1kHz/1W)
• Power Consumption: 250VA
• Dimensions: 365mm(W) x 305mm(D) x 225mm (H)
• Weight: 21.5kg

Air Tight's Reference Line

ATM 3211 - Reference Mono Power Amplifier

Airtight's dream came true in 2017 with their 120W output from exquisite 211 Triode push-pull circuitry.

The circuit configuration is as follow:
- 1st stage: differential circuit of 12AX7
- 2nd stage: 12BH7
- Cathode-follower 12BH7 parallel
- A-class operation up to 30W
- AB-class operation for more than 30W
- Wide frequency range is obtained by NFB circuit (Frequency response 10Hz～50ｋHz　±１ｄB)
- Massive Tamura’s output transformer is employed
- High and low 2-compositions transformer ensure instantaneous power supply and prevent power interference.
- High grade capacitors and resistors are employed in key locations.
- The 15mm thick aluminum front panel is carved by hand.
- WBT input and speaker terminals are employed.
- Wiring and soldering are all done by hand.

Specifications:

Valves employed: 12AX7 x 1, 12BH7 x 3, 211 x 2
Rated output: 120W (6Ω/THD2%)
Frequency response: 10Hz~50kHz (±1dB/THD0.06%)(at 1kHZ/30W)
Damping factor: 6(1kHz/1W)
Input sensitivity: 1V/Input impedance 100kΩ
Power consumption: 550VA
Load impedance: 6Ω/16Ω(Interchangeable, 6Ωstandard)
Dimensions: 400(W) x 450(D) x 405(H) mm
Weight: 44kgs

AWARDS

2025 Golden Ear Award
The Absolute Sound Printed Magazine

Downloads

Airtight's PDF specification

ATM-2001/ATM-2001S

Superdreadnought Mono Power Amplifier / Stereo Power Amplifier

Features

- Comfortable high power thanks to colossal output stage featuring 12 pieces of 6550 beam valve
- Individually direct-coupled cathode-follower to ensure an optimum operation of each output valve
- Massive power supply employing huge EI power transformer
- 2 independent amps thus composed in UL configuration afford rich high power without load on each component
- Lavish employment of strictly select components of high performance & long durability

Specifications

Valves employed: 6550 × 12, 12BH7× 6, 12AX7× 2, 12AU7 × 2
Rated output: 338W(8 ohms, mono) / 180W(8 ohms,stereo)
THD: less than 1% at rated output
Frequency response: 20 - 20,000Hz( 1dB)
Input impedance: 100k ohms
S/N ratio: 100dB
Dimensions:
power supply: 430(W) ×185(H) ×500(D)mm
amplifier: 430(W) ×380(H) ×520(D)mm
Weight:
power supply: 65kgs
amplifier: 50kgs

AirTight's Single-Ended Triode Power Amplifiers

ATM-2211 - Monaural Power Amplifier

About 20 years have passed since the launch of the ATM-211 single-monaural power amplifier using 211 tube, which has been well received since its launch in 2001. Since then, AIR TIGHT launched 211 push-pull monaural power amplifier ATM-3211, which has become a turning point for the Airtight brand as well as SET ATM-300R. For their 35 year anniversary, AIR TIGHT will launch the new 211 single monaural power amplifier ATM-2211.

Specifications/Features:

Valves employed: 1/12AX7, 1/12BH7, 1/211
Rated output: 32W(THD<5%)
Input impedance: 100kΩ(RCA/XLR)
Input: RCAx1, XLRx1(No.2 pin=HOT)
Input sensitivity: 500mV(32W)
Frequency response: 20Hz~20kHz(-1dB) @3.5W
Power consumption: 250VA
Dimensions: 400(W)x350(D)x225(H)mm
Weight: 25.5Kg

Downloads

Airtight's PDF specification

Air Tight Power Amplification

ATM-300R

Stereo Power Amplifier

ATM-300R was developed as a reference model to show off the &lquo;Warm and Soft&rquo; sound of conventional 300B amplifiers and applauded enthusiastically, the ATM-300 was supported by many audiophiles in the world. In order to reflect the individuality of a wide variety of 300B , AIRTIGHT built a sound stage full of musicality that allows the sphere to fully demonstrate its potential while suppressing the colouring of the sound as much as possible. As a result, while making full use of the individuality of the sphere, they have realized the freshness that the music permeates, the vast and deep sound field, and the dynamics that makes one forget the specifications of a 9W output.

Specifications

Power Output : 9W＋9W (THD<10%) THD below : 1% (1kHz / 1W / 8Ω) Input Sensitivity : 290mV (9W) Damping Factor : 7 (1kHz / 1W / 8Ω) Frequency Response : 30Hz～40kHz (−1dB / 1W) Dimensions : 430(W)×275(D)×245(H)mm Weight : 24.5kg

Downloads

Airtight's PDF specification

ATM-2Plus

Stereo Power Amplifier

“Rediscovery of the legends”
Air Tight released the original ATM-2 in 1988. This KT-88 based Push-Pull power amplifier received honor of many awards and has became our longest running power amplifier model for over 30 years. Today, we are renovating this celebrated model to redefine KT-88 push-pull amplifier with AirTight`s30 years of technical expertise.

The new ATM-2Plus is a completely new design while keeping the legendary AirTight style & outlooks. All circuity including 1st& 2nd amplification and internal constructions are renovated. Unlike a time when we released the original ATM-2, vintage KT-88 tubes are almost impossible to obtain, and quality of modern tubes are different. Our focus was to lower plate voltage of the tube while keeping output power for longer tube life as well as stable operation of the amplifier.

For the optimum operation point of KT-88/6550 tubes, we incorporated 6CG7/6FQ7 tubes which is more powerful than the original 12AU7 for wider amplitude and lower distortion. AirTight also redesigned Negative Feedback to optimize damping factors to match with today`s speaker. Output transformer is a major components for Power Amplifier. ATM-2Plus is unsparingly mounting new Tamura`s 100W class large output transformers to allow surplus at lows. For critical power transformer, we decided to custom made hand-winded/paper wrapped transformer made by Japanese craftsman for clearer and bigger sound stage.

Exterior design of ATM-2Plus is adhere to its predecessor, but the new chassis design hides fasteners by using stud boss and ensuring firm frame grounding. Another new features would be fast breaking fuses to protect the amplifier from output tube failures.

Keeping traditions, not printed circuit boards are used in ATM-2Plus, and all assemblies and wirings of ATM-2Plus are done by our craftsmen at AirTight factory in Takatsuki, Osaka.

Specifications

Design: Push Pull
Valves Employed: KT-88/6550 (Fixed Bias) 12AX7 x2, 6CG7/6FQ7 x4, KT-88/6550 x4
Rated Power Output: 70W+70W (1kHz/THD>5%)
Input Impedance 100 kohms Input: 2 Channels (1 x Back, 1 x Front, both RCA)
Load Impedance: Low 4Ω / High 8Ω (16Ω option)
Features: Input Selector Switch, Bias Adjustments
Frequency Response : 10Hz~60kHz(@-1dB/1W), 20Hz~50kHz(@-1dB/50W)
Dimensions : 415mm(W) × 380mm(D) × 230mm(H)
Weight : 33kg

Downloads

Airtight's PDF specification

ATM-1 2024 Edition

Stereo Power Amplifier

After launch of the original “ATM-1” in 1986 and “ATM-1s” in 2006, the EL-34 push-pull amplifier” has been updated for the first time in 18 years as “ATM-1 (2024 edition)”. While following the orthodox yet sophisticated design of the original model and the concept of “a tool for listening to music”, we selected the best parts currently available and designed an amplifier that allows the EL-34 to provide more stable performance.

Authentically designed to bring out the best of EL-34
The circuit configuration is a typical Leak-Mullard type. We choose to use UL connection from the balance between quality and output prospective to draw stably outputs of 35W+35W. We focused on authenticity over novelty, balance over uniqueness, and focused on bringing out the wonderful characteristics of the EL-34. The output transformer and choke coil are made by reliable Tamura. The bias circuit has a fixed bias, and a custom-made precision vertical edgewise meter has been adopted for ease of adjustment and ease of viewing and matching.

The input terminal is a single RCA system. The terminal can be changed to XLR Unbalanced Input (2nd pin HOT) by request. Speaker Terminals are sent to 4Ω/8Ω. The terminal can also be changed to have 16ohm by request. All components are carefully selected through sound checking, and carefully mounted and wired on pure copper sub-chassis by our experienced amp craftsmen.

Traditional AirTight Chassis design
The appearance of “ATM-1 2024 edition” resembles the original ATM-1 design, but we have made modern updates and paid attention to every details throughout. The main chassis is a monocoque construction that combines strength and acoustic benefits. The exterior has been designed to prevent screw heads exposure, and a thick aluminum front panel is mounted as the face of the amplifier. The bottom plate is made of bright copper plated steel.

The amplifier is made to compact in size to appeal the slim modern EL-34 shape while feeling sense of weight and has a dignified sharpness, inheriting the "AirTightness" that has existed since the company's founding.

Specifications

Valves Employed: 1/12AT7(ECC81), 2/6CG7 (6FQ7), 4/EL34
Rated output: 35W+35W (1kHz/THD<5%) Frequency response: 20Hz~30kHz(-1dB/30W) Input impedance: 100kΩ Input sensitivity: 700mV(35W) Dumping factor: 6.7(1kHz/1W) Power consumption: 250VA Dimensions: 365mm(W) x 305mm(D) x 225mm (H) Weight: 21.5kg

Downloads

Airtight's PDF specification

ATM-1S stereo power amplifier

ULTIMATE DESIGN FOR SONIC IMMACULACY
- Dependable orthodox configuration composed of highly acclaimed 6CA7 valves under Mullard phase inversion
- Hefty output headroom achieved by newly developed Hashimoto transformers boasting of 60W power handling capability
- Bias adjustment facilities for easy service accessibility
- No PCB in favour of point-to-point manual soldering with full OFC wires and copper-plated chassis

Specifications

Valves employed: 6CA7 × 4, 12AU7 × 2, 12AX7 × 1
Rated output: 36W + 36W (8 ohms)
Input sensitivity: 1V
Input impedance: 100kohms
Load Impedance: ４Ω/８Ω/16Ω　Interchangeable by inner wiring.
Set at 8Ωload when shipped from the factory.

Features

Input selector (2-ch), bias adjuster
Dimensions: 368(W) × 293(D) × 231(H)mm
Weight: 22kgs

Downloads

Airtight's PDF specification

AirTight Pre Amplifiers

ATC-7

Specifications
Valves Employed: 12AX7 x 2, 12AU7 x 2
Inputs 5: RCA x 3, XLR x 2
Input Impedance: 100kΩ (19dB gain)
Output: RCA x 2
Output impedance/ (recommended Load: Total>47 kΩ)
THD: 0.02% (1V/1kHz)
Output Voltage: 20V (Load 100 kΩ/1% THD)
Frequency Response: 10Hz~100kHz (-1dB)
Power Consumption: 50VA
Dimensions: 400mm(W), 350mm(D), 145mm(H)
Weight : 13.5k

ATC-5S

Specifications
Valves employed: 12AX7 × 3, 12AT7 × 2
Phono equalizer input: RCA/MM × 2
Input impedance: 47kΩ（Gain 40dB）
Phono equalizer output: RCA × 1
Output impedance: Recommended load more than 47kΩ
Line input: RCA × 3
Input impedance: 47kΩ (Gain 18dB)
Line output: RCA × 2
Output impedance: Recommended load more than 47kΩ
Output voltage: 20V(Load 100kΩ/1% distortion)
Line amplifier distortion: THD 0.02%(1V/1kHz)
Frequency response Phono equalizer: 50Hz~20kHz(±0.2dB) /20Hz-2.5dB
Frequency response Line amplifier: 20Hz~100kHz-1dB
Power consumption: 50VA
Dimensions: 400(W) × 260(D) × 90(H)(tentative)
Weight: 9kgs(tentative)

ATC-3

Stereo Line-Control Amplifier

Features
- SRPP line amp with reinforced buffer stage to assure good noise rejection, low output impedance and extended linearity
- Rich power supply featuring quick recovery diode for high operational speed and low pulse noise
- Single-steel sheet with multi-layer enamel for high rigidity and low noise
- High-quality input/output jacks with detachable mains cord
- Optional ‘Alps’ high-precision pot RK-501

Specifications
Valves employed: 12AX7(ECC83) × 1, 12AU7(ECC82) × 2
Output voltage: rated 2V, max. 15V
Output impedance: 200 ohms
THD: less than 0.01%
Input sensitivity: 110mV (ouput 1V)
S/N ratio: less than 90dB (IHF-A weighted)
Dimensions: 430(W) × 325(D) × 90(H)mm
Weight: 8kgs

AirTight Phono Equalizer

ATE-3011

BUILD TO ORDER - Reference Phonostage

ATE-3011 is Airtight's latest phonostage, born for music lovers who thoroughly enjoys the profound world of record reproduction. The ATE-3011 is equipped with 5 equalizing curves (RIAA, NAB, AES, FFRR, & FLAT) for Turnover and Roll-Off, and can independently select turnover and roll-off to create various curves to optimize for your vinyl collections.

Large-size self-illuminating display and equalize curve selector switch offers easy change over between the equalizing curves which often requires intricate settings on other equalizer, and now music lovers can focus on appreciation of recorded music.

Features

- Genuine valve configuration for whole amp stages even at power supply
- Latest sonic-oriented high-quality attenuator for matchless sonic transparency and silky smoothness
- EQ circuitry composed of 2-stage NF & SRPP to insure wide-band spectrum and minimum distortion
- Elaborate power supply for high stability and low noise
- Direct-accessible EQ output bypassing volume pot
- High-mass, vibration-proof chassis for high rigidity

Specifications

Valves employed: 12AX7 x 3
Phono equalizer input: RCA/MM × 3
Input impedance: 47kΩ（Gain 40dB）
Phono equalizer output: RCA × 2 + 1(mono only)
Output impedance: Recommended load more than 47kΩ
THD: 0.02%(1V/1kHz)
Frequency response: 50Hz~20kHz(±0.2dB) /20Hz-2.5dB
Power consumption: 50VA
Dimensions: 400(W) × 375(D) × 151(H)mm
Weight: 12.2kg

Downloads

Airtight's PDF specification

Step-Up Transformers

ATH-3S

MC Step-Up Transformer

Airtight is renewing MC Step-Up Transformer ATH-3 to a new model “ATH-3s”.
The new ATH-3s is equipped with Ground Lift Switches, which enable to select grounded and floated grounding individually for input and output. This feature makes it possible to handle from floating balanced transmission to normal transmission.

Along with that, the housing and insulator are also changed to aluminum to improve the sound quality. We chose a ground lift switch that was particular about the feeling. It has been well received by ATE-3011,
We also incorporates a Hexagon Nut Binding Post MIL-P-55149 / 8 (MIL Standard), the same GND terminal we use for our flagship Phonostage ATE-3011.

Specifications
Step-up ratio: 1:40 (32dB gain) at low impedance mode
Adaptable impedance of cartridges: 1Ω〜7Ω (Recommended)
＊ High Impedance model for 7Ω〜40Ω available (factory set)
Dimensions: 144 (W) × 207 (D) × 80 (H) mm
Weight: 1.5kgs

ATH-3

Step-up transformer for MC cartridge

Specifications

Step-up ratio: 1:40 (32dB gain) at low impedance mode
Adaptable impedance of cartridges: 1Ω〜7Ω (Recommended)
> > >The adaptable impedance range can be converted to 7Ω〜40Ω.

Dimensions: 144 (W) × 207 (D) × 80 (H) mm
Weight: 1.5kgs

ATH-2 REFERENCE

Step-up transformer for MC cartridge

The ATH-2 REFERENCE is Air Tights top version of the ATH-2A. The ATH-2 REFERENCE has three selectable inputs, i.e., "Bypass", "2Ohm" and "40Ohhm". Thanks to the employment of the new winding material (oxygen-free copper) and careful review on its winding method, the dynamics-range, sonic powerfulness and quality have been remarkably improved, thus achieving an unparalleled musicality of your analogue discs.

Features

- frequency rage being fully procured, the upper-end is extend up to 80kHz (-1dB) and 120kHz (-2.2dB).
- S/N ratio especially at the low output level totally surpassing the competitors' performance, you may enjoy the higher quality in the different dimension in combination with the Hi-End amplifiers
- 2 Ohm position complies with the latest ultra-low impedance below 1 Ohm

The ATH-2 REFERENCE derives the full potentials of the existing MC cartridges, starting from the Ortofon SPU down to the latest

Specifications

Input Selector - ３ position
・Bypass: without gain, for MM cartridges
・2Ω　(0.6Ω～7Ωapplicable)　gain 29ｄB　
・40Ω　(7Ω～40Ω applicable)　gain 23ｄB
Frequency response: 10Hz～80ｋHz　(-1dB)
Dimensions: 240(W)×180(D)×70(H)mm
Weight: 2.8kgs

Reviews

RK-501

High-precision volume

Features

A unique polished solid brass enclosure resistant to vibration and resonance with a newly developed carbon resistor offers unsurpassed sonic transparency and silky-smooth touch to level control. Available at option for the ATC-1, ATC-2, ATC3

Images from Angie's Trip to Air Tight

Cartridges from AirTight

Opus-1

Exclusive SH-uX core sealed in ultra-hard duralumin housing fortified by nickel plating

Specifications
Type: Ultra Low Impedance MC phono cartridge
Frequency range: 10-50,000Hz
Internal impedance: 1.4 ohms (DCR)
Output voltage: 0.45mV/1kHz
Magnet: Neodymium#50
Tracking force: 2.0-2.2g
Dynamic Compliance: 8x10⁻⁶Cm/Dyne
Cantilever: Boron Cantilever
Stylus Tip Type: Semi-line contact (3μmm×30μmm)
Channel balance: Less than 0.5dB/1kHz
Cross talk: More than 30dB/1kHz
Cartridge base: A7075(DLC plating)
Housing: A5056(Rhodium plating)
Terminal: Rhodium plating
Weight: 12.5g

PC-1 Coda

It’s been over a decade since the first AirTight MC cartridge PC-1 made its debut.The PC-1 was well received and soon after became a reference cartridge model among audiophile for its dynamic sound, surprising low impedance, and high voltage output that beats common wisdom to MC cartridge. AirTight continued to PC-1 Supreme, and in 2016, released Opus-1, a cartridge with totally renovated mechanical constructions and power train as our 30 years anniversary and a flagship model. Today, we are pleased to announce debut of PC-1 coda, a new MC Cartridge pouring technologies and knowledges from our years of designing Cartridge.

Phono Cartridges pick up sensitive musical information from sub-micron grooves, and body of cartridge that holds power generator/coils and magnets tremendously influences sound reproducing quality. From our very first PC-1 cartridge, AirTight has been using precisely machined metal cartridge base for deeper lows and higher sound resolution, and as the compilation of techniques, at Opus-1 we reached to Super Aluminum alloy A7075 which has one of the highest strength in Aluminum alloys. Over the course of development, we tested with many different types of alloys with higher strength, frequency responses, and/or having unique sound but we decided not to use such alloys as we believe that sound shall not be affected by the materials and should be selected purely from true reproduction of music. The A7075 was selected as the alloy of the choice for less sound coloration. We added Chrome coating in addition to thick 50 μ Nickel base coating to the alloy for deeper sound resolution.

We are retrofitting this technology on PC-1 coda, and using the A7075 as a cartridge base alloy, giving sharper and speedy lows and clearer sound stage compared with its predecessor PC-1/PC-1s. We also finetuned suspension mechanism from raw material for firm and high resolution sound images in atmosphere. As the same to PC-1/PC-1s, "Boron" an alloy with good physical characteristics has been used for Cantilever material.

Specifications
Internal impedance: 1.7 ohms (DCR)
Output voltage: 0.5mV/1kHz
Stylus pressure: 2.0 - 2.2g
Channel balance: within 0.5dB/1kHz
Cantilever: boron
Stylus Tip Type: Semi-line contact (3 μ mm × 30 μ mm)
Cartridge base: A7075 (Extra Super Duralumin)
Housing: A6063
Terminal: Rhodium plating
Weight: 12.7g

PC-1 Supreme

Epoch-making Hi-µ core material SH-µX recently developed offers high µ amount to realise high-efficiency magnetic circuitry. Thick wires help reduce winding Nos. in coil, thus achieving astounding low internal impedance. Expanded bandwidth & extended dynamic range present clearer life-like soundstage, whilst improvement in transient & phase characteristics reproduces ultra-heavy bass with highest resolutions.

Specifications
Internal impedance: 1 ohm (DCR)
Output voltage: 0.4mV/1kHz
Stylus pressure: 1.9 - 2.2g
Channel balance: within 0.5dB/1kHz
Dynamic Compliance: 8x10⁻⁶Cm/Dyne
Cantilever: boron
Weight: 12g