Vacuum tube type monaural power amplifier with large triode 212E. Plate voltage 1,400V, output 40W. No-feedback technology creates a three-dimensional and spontaneous sound.
Large triode 212E
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.
Two-stage configuration with C3g
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.
High fidelity input transformer
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.
Original design and development of dual regulated power supply
It employs a dual regulated power supply with a switching regulator in the first stage and an after-analog regulator in the second stage, which has been optimized for audio based on many years of knowledge in power supply development.