On the eve of the 35th anniversary of the Japanese brand Air Tight, the new ATM-2211 monaural power amplifier with the 211 valve is officially introduced. Due to this launch, the ATM-211 is now discontinued.

Air Tight says: "This time, we decided not to use general negative feedback (NFB) from the secondary part of the output transformer, but to apply a large amount of NFB from the 211 output valve plate to the first stage. This is because it emphasises the power of sound penetration and energy sensation rather than the so-called characteristic correction. The operating point of each circuit component was designed more strictly and increased the output to 32W. The ATM-2211 uses a fixed bias method and DC ignition for the filament".

Transformers

Air Tight has used separate transformers for high and low voltage which used to be integral type in earlier models. In addition, the choke coil, which can be said to be the heart of the stage, is made of layers that do not use traditional coils and are specially made to withstand high voltage. These choke coils are individually handmade by Japanese craftsmen. For the output transformer, they have installed a high performance transformer manufactured by Hashimoto Electric Co.

Monocoque chassis

The main chassis is the traditional Air Tight monocoque construction that controls resonance and maintains the mechanical strength of the amplifier. A thick pure copper chassis is suspended from the main chassis to support the main amplifier board and the power supply section in which the big block capacitor is placed. The main chassis has a structure using a threaded bolt where the bolt head is externally invisible. The thick front panel is machined from a solid aluminium block.

WBT terminals

The speaker terminals manufactured by WBT in Germany are separately equipped for high (8Ω) and low (4Ω) output (16Ω can be selected as a factory-set option). The input terminal is equipped with selectable RCA and XLR options. When the power is turned on, a built-in timer relay is activated and the board voltage is applied with a time difference. This contributes to the protection of the output valve when the power is turned on and a longer lifetime of the snubber capacitors in the power supply section. As the 211 valve operates at very high voltage, Air Tight has carefully selected parts to withstand the high voltage and long term use.

Features:

Valves: 1 x 12AX7, 1 x 12BH7, 1 x 211

Rated output: 32 W (THD <5%)

Input impedance: 100kΩ (RCA / XLR)

Input: 1 x RCA, 1 x XLR (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: 25.5 kg