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50 watts of Class A power from a single 212E triode.
Two amplification stages. No negative feedback.
About the 212PAM2
The 212PAM2 amplifier brings together large-triode amplification and CS Port’s specialist power-supply engineering.
A single 212E output tube forms the centrepiece of each amplifier, matched by an architecture focused on a short amplification chain, carefully designed transformers and stable operating conditions.
The narrow chassis combines anodised aluminium with rosewood detailing, giving each monoblock a distinctive appearance alongside its exposed output triode.
The 212E Output Triode
Originally developed for transmission and modulation applications, the 212E offers the linear characteristics required for audio amplification.
The tube at a plate voltage of 1,400 V, producing 50 watts in Class A. The operating point balances output capability with a specified damping factor of at least five.
Separate 4- and 8-ohm loudspeaker connections are available to accommodate a wide range of loudspeakers.
Two-Stage Amplification with C3g
The driver stage uses a C3g connected as a triode, feeding the 212E output stage. Only two valves perform the amplification in each monoblock.
This arrangement relies on the linearity of the individual stages rather than negative feedback to correct their combined behaviour. CS Port’s design seeks to control harmonic and intermodulation distortion through the circuit itself.
Custom Input Transformer
A high-permeability Super Permalloy input transformer supplies additional voltage gain, allowing the amplifier to retain its two-stage valve architecture.
Its core material, winding geometry and turns ratio are developed as part of the complete circuit. Balanced XLR and unbalanced RCA inputs provide a choice of connection.
Doubly Regulated Power Supply
The 212PAM2 combines a switching regulator with a subsequent analogue regulation stage to stabilise the high-voltage supply.
This approach draws on CS Port’s experience in power-supply development, addressing regulation and noise within the supply architecture.
Controlled start-up limits output-tube filament inrush current and delays application of the high voltage, allowing the filament to warm before normal operation begins.
Type
Class-A monaural valve power amplifier
Valve Complement, per Monoblock
1 × C3g driver, triode-connected
1 × 212E-family output triode
Output Power
50 W into 4 Ω or 8 Ω
Frequency Response
20 Hz–40 kHz, −3 dB at 20 W
Total Harmonic Distortion
5% at 50 W, 1 kHz
Negative Feedback
None
Signal-to-Noise Ratio
90 dB, referenced to 10 W into 8 Ω
Input Sensitivity
1.2 V for 50 W output
Gain
25 dB into 8 Ω
Inputs, per Monoblock
1 × balanced XLR
1 × unbalanced RCA
Input Impedance
1.5 kΩ
Recommended Source Output Impedance
300 Ω or less
Damping Factor
5 or greater
Mains Supply
100/120/200/240 V AC, 50/60 Hz
Voltage configuration to be confirmed when ordering
Power Consumption
400 W per monoblock
Dimensions, W × H × D
188 × 370 × 563 mm
Excluding feet, knobs and terminals
Weight
24.5 kg per monoblock
Finish
Anodised aluminium with rosewood detailing
Manufacturer’s Warranty
Five years, excluding consumables such as valves