212E ClassA Monaural Power Amplifier


A vacuum tube type mono power amplifier equipped with the large triode "212E". For low distortion rate operation, a plate voltage of 1,400V is applied. The plate current is 130mA, and the output is 40W. Using a switching power supply even at a high voltage of 1,400V realizes safety, lightweight and compact design. In addition, nonfeedback fills the sound with a three-dimensional elongation and faithfully reproduces the original sound. Miniaturization with a switching power supply increases the flexibility of the design, and the casing with a rosewood projecting plate creates an elegant presence in the listening room.


Large 3-electrode tube 212E mounted

This is a large triode with a plate loss of 275W in a transmitting tube and a modulating tube. A class-A single tube amplifier has a small output and is difficult to drive low-efficiency speakers, but this unit is a full-fledged amplifier that operates at a plate voltage of 1,400V and drives at a 40W output. It also suppresses the output to gain a damping factor of 5 or more and reliably drives the low frequencies as well.

* Western licensed STC4212E from the 1960s to the 70s and equipped with Nishikyushu photoelectron tube 212E


Two-step configuration with an ultra-high confidence tube C3g

Equipped with ultra-reliable pentode C3g developed by Deutsche Telekom for telephone repeaters. Since the grid line is thin and the distance between electrodes is large, voltage amplification with high linearity is possible. This unit is composed of only two amplifier tubes with 212E, which suppresses harmonic and mixed modulation distortion while providing no feedback.


High fidelity input transformer

In the two-stage amplification, the insufficient gain is produced by the input transformer. A high-linearity transformer using a high-permeability super-malloy core that passes through micro-signals without adding any extra material.

* Because the input impedance is as low as 1.5kΩ, drive with a device with an output impedance of 300 Ω or less.


Noise suppression at the contact point

Many contact points in the amplifier are the source of noise due to the rectifying action at the micro level. (The rectifying action of the metal oxide film is especially large.) The internal signal path is designed without using a connector to prevent noise generation, and the direct current flow section uses a gold-plated connector.


Model 212PA
Method Input transformer built-in Class A operating vacuum tube type mono power amplifier
Configuration )Input Transformer-C3g3 Connection-FET Driver-212E-Output Transformer
Output 40w (Load impedance 4Ω · 8Ω)
Frequency characteristic 20 - 40kHz -3dB / 20W
Total harmonic distortion 1% / 40W 1kHz, 0.2% / 10W 1kHz
NFB None
Signal-to-noise ratio 90dB / 10W(8Ω)
Input sensitivity 1V / 40W
GAIN 25dB(8Ω)
Input impedance 1.5kΩ
Volume adjustment By the front volume
Dumping factor 5 or more
Speaker connection 4 Ω/8 Ω terminal
Power supply AC 100 / 120 / 200 / 240V 50,60Hz
Power consumption 400w
Size 188W × 385H × 563D knob/terminal not included
Weight 24.5kg
Finish Silver alumite and rosewood thrust plate
Accessories Rhodium-plated AC power cable
Warranty period Registration is required for 5 years (excluding consumables).

  • Two models: 212PA-ST with 4212E (vintage) manufactured by STC, and 212PA-JH with 212E (new) manufactured by Nishikyushu Kodenshi
  • STC 4212E is a rare product, so please contact us before purchasing it.
  • Do not touch the tubes as they are hot and may cause burns.
  • The input impedance of this unit is 1.5kΩ. Drive with an output impedance of 300 Ω or less.
  • Changes in specifications, design, design, price, etc. may be made without prior notice.