Air Tight ATC-7
Statement Stereo Preamplifier
These days modern design dictates that most basic functions of an amplifier are integrated into a remote control or a touch screen or a mobile phone/tablet via Wi-Fi or Bluetooth. This is certainly convenient however an important aspect of audio pleasure has been lost. One aspect of operating an Air Tight amplifier is the sensation of turning a knob and experiencing the tactile sensation of a physical interaction between the human being and the equipment. Great care has been taken to design the knobs with a texture that feels right to the touch, with the ideal knurling feel and rotation inertia. There is something deeply satisfying about this process!
Another Air Tight defining characteristic is the physical solidity, weight and quality of the piece. There is a real presence or gravitas about these meticulously hand made objects of desire. They look like a piece of equipment that doesn’t age and will look just as good in thirty years as it does today, a real heirloom piece that once created, will be passed own to future generations.
Perhaps the most important aspect of Air Tight ownership is the enjoyable, fulfilling sound quality. When these amplifiers are conceived, developed and perfected, no deadlines are set. They simply take as long as they need to. Every possible idea is explored and a long process of refinement and evolution is undertaken to eventually arrive at the Air Tight sound. The ATM-7 is a preamplifier of the highest calibre and incorporates a number of technologies that are unique to it. The power supply circuit contains a rare regulation topology with a choke coil. The housing is a combination of new and traditional Bakelite & Steel. It takes the Air Tight philosophy and design priorities and expresses them to their full potential. Air Tight have said “this is the preamplifier that we’ve always wanted to make”.
The sound has that sophistication that can only come with decades of experience. There’s a vividness, depth and dignity to the sound that emerges from the speakers. The music is balanced with a sense of naturalism and vividness as we have come to expect from these artisans of the Japanese tradition. In our opinion, this preamplifier has a charm that celebrates the joy of listening to music. Strip away the remote controls, the screens, flashing lights and all the gimmicks. Keep it simple, elegant and understated, then make it the best it can possibly be. Perfect.
The key to the purity of the sound is the unique hand-made toroidal transformers with low leakage flux that are used in the power supply. Two transformers, one for high-voltage power supply and the other for low-voltage power supply, are installed and rigidly mounted on the main chassis by thick pure copper substrates. A new high-performance fully regulated power supply designed exclusively for the ATC-7 reduces the effects from flickers from commercial power supplies and provides clean and stable power via a high-performance audio signal range choke coil. In addition, a large capacity film capacitor in the decoupling circuit is incorporated. Electrolytic capacitors are eliminated from both the signal and the decoupling circuits which contributes to the transparency of the sound.
A mechanical rotary selector switch which resists degradation over time is used for the input selector. The ATC-7 is equipped with 3 x RCA inputs and 2 x XLR inputs. PTFE insulated high-density, high-quality shielded wires are used for the cables from each input terminal, minimising the loss of audio signals and suppressing crosstalk between the left and right channels. “Presence control”, “Bass Compensator”, and “Gain Trim” are equipped with mechanical rotary switches that provide a nimble operational feel, providing joys of adjusting the sound quality. The Left and Right channels are configured back-to-back inside an inner chassis which is suspended from the top of the main chassis and a pure copper shielding plate is arranged in between to prevent interference. For the critical role of main volume adjustment, the ALPS RK-501 high quality volume mechanism is incorporated.
This is a 2-stage NF type SRPP (shunt regulated push-pull) consisting of a twin triode 12AX7 and a 12AU7 for each channel. A mirror configuration in which the L/R channel amplifiers are arranged vertically symmetrically. The amplification section is housed in a black chrome-plated inner chassis, and printed circuit boards are fixed on a thick pure copper bathtub-shaped substrate inside. The inner chassis is firmly fixed from the ceiling of the monocoque chassis via a specially made Bakelite bar. This Bakelite bar provides electrical isolation of the amplification unit from the main chassis while mitigating resonance. The front panel is made of 15mm thick aluminium cut with an NC lathe, and the surface is anodized. Equipped with a timer relay circuit when the power is turned on, even when combined with a solid-state power amplifier, noise is not generated when the power is turned on.
|Type||Stereo line-control amplifier (Preamplifier)|
|Tubes||12AX7 x 2, 12AU7 x 2|
|Inputs||RCA x 3, XLR x 2 (Input Impedance 100kΩ – 19dB gain)|
|Outputs||RCA x 2|
|Output Impedance||More than 47kΩ in total|
|THD||0.02% (1V / 1kHz)|
|Output Voltage||20V (Load 100kΩ / 1% THD)|
|Frequency Response||10Hz – 100kHz (-1dB)|
|Dimensions||400mm (W) x 350mm (D) x 145mm (H)|
Features & Specifications
Stereo Line Preamplifier
1 x 12AX7(ECC83), 2 x 12AU7(ECC82)
Rated 2V, max 15V
Less than 0.01%
110mV (output 1V)
Signal to Noise Ratio
Less than 90dB (IHF-A weighted)
430mm(W) × 325mm(D) × 90mm(H)