CSPort Monaural Power Amplifier 212PA

The 212E is a transmitter and modulation tube with a plate loss of 275W, developed by Western Electric in the 1910s. Class-A single tube amplifier has difficulty driving a low efficiency speaker, but this unit has a plate voltage of 1,400V and an output of 40W. The damping factor of 5 or more is achieved by reducing the output power, so it can drive the low frequency range reliably.

*Two models are available: STC’s 4212E (1960-70s production) and Jinzhou Electronics’s 212E.

It is equipped with the ultra-reliable C3g, developed by Deutsche Telekom for telephone repeaters. The thin grid lines and large distance between electrodes enable high linearity amplification. By using only two tubes of amplification with the 212E, harmonics and mixed-modulation distortions are suppressed though no-feedback.

The input transformer makes up for the lack of gain in the two-stage amplification. It is received by a high linearity transformer with a high permeability super permalloy core and does not add anything extra.

* The input impedance is 1.5kΩ, and should be driven by equipment with an output impedance of 300Ω or less.

The rectifiers and contacts used in general power supplies are a source of noise, and the quality of the power supply is also the quality of sound. An after-analog regulator is installed at the rear of the unit to completely clear the noise level. The use of a switching regulator has made it possible to stabilize a high voltage of 1,400 V and to reduce the weight of the unit by 24.5 kg.

Specification