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Threshold Audio 400A

Class-A Stereo Power Amplifier (1979)

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Threshold Audio 400A


The Threshold model 400A embodies Threshold's direct solutions for those basic anomalies to which the human ear is most sensitive.

The 400A achieves virtually perfect program signal processing insofar as aural perception is concerned through the use of an ingeniously simple circuit path and the operation of all gain devices in the class A mode at all times and under all signal conditions short of actual amplifier clipping.


Power output: 100 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 20kHz

Total harmonic distortion: 0.1%

Damping factor: 100

Gain: 23 dB

Dimensions: 19 x 7 x 11 inches

Weight: 51.5lbs


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This website is not affiliated with or sponsored by Threshold Audio. To purchase 400A spares or accessories, please contact the company via their website or visit an authorised retailer.