CS Port GM70 ClassA Stereo Power Amplifier

Another addition to the CS Port impressive portfolio is CS Port GM70 ClassA Stereo Power Amplifier, based on the GM70 tube. "This is a full-fledged product with a plate voltage of 1,050V applied for low distortion rate operation and output of 30W+30W drive. In addition, using a switching power supply even at a high voltage of 1,050V realizes safety, light weight, and compact size. Non-feedback creates a three-dimensional and realistic feeling and creates a clear sound."

Installation of the former Soviet triode GM70

It is bigger than Pp=125W and 845 (Pp=100W) in one cycle, and is equipped with a low-impedance, direct-heat triode GM70, with outputs of 30W+30W (4Ω) and 20W+20W (8Ω), and it can also drive mainstream low-efficiency speakers in recent years.

Equipped with ultra-high reliability tube C3g

To Deutsche Telekom's telephone relay Developed Equipped with ultra-high reliability 5-electrode tube C3g. High linearity voltage amplification is possible because the grid line is thin and the distance between electrodes is large. This unit does not use a socket, but solders directly to the board to suppress noise generation at the contact point.

Large output transformer with sufficient margin

Equipped with a large-output transformer developed for GM70PA. Multi-layer sandwich winding drives a wide band from minute to large signals. The low winding resistance and drive capability provide a large damping factor of 5 or more as a feedback-free amplifier, securely driving the low frequencies.

Normal, Dual, Bridge Mode Switching

You can use it as a stereo amplifier with a NormalMode, and as a bi-amp with an additional unit that drives the high and low frequencies with a DualMonoMode. The BridgeMode also allows outputs to be doubled from 1.5.

* Other than NormalMode, it is enabled when Lch/XLR is inputted.

  • Model GM70PA
  • Method Input transformer built-in Class A operation vacuum tube type stereo power amplifier
  • Configuration Input transformer-C3g 3connection-FET driver-GM70-output transformer
  • Output
  • Normal, DualMonoMode...30W+30W(4Ω, THD 5%)
  • Normal, DualMonoMode...20W+20W(8Ω, THD 5%)
  • BridgeMode...60W(8Ω, THD 5%)
  • BridgeMode...40W(4Ω, THD 5%)
  • Frequency Response 20 - 30kHz -2dB / 10W
  • Total harmonics distortion
  • Normal, DualMonoMode...0.7% / 10W
  • Normal, DualMonoMode...0.2% / 1W
  • BridgeMode...0.5% / 10W
  • BridgeMode...0.1% / 1W
  • NFB None
  • Signal-to-noise ratio 90dB / 1W(20-20kHz)
  • Crosstalk 40dB / 1W(20-20kHz)
  • Input sensitivity
  • Normal, DualMonoMode...1V / 30W(4Ω)
  • Normal, DualMonoMode...1V / 20W(8Ω)
  • BridgeMode...1V / 60W(8Ω)
  • BridgeMode...1V / 40W(4Ω)
  • GAIN 21dB
  • Input connection One RCA and one XLR system
  • Input impedance 2.5kΩ 1kHz
  • Mode switching By the rear rotary switch
  • Volume adjustment None
  • Damping factor
  • Normal, DualMonoMode...2.8(4Ω), 5.6(8Ω)
  • Power supply AC100 / 120 / 200 / 240V, 50 / 60Hz
  • Power consumption 400W
  • Size 470W × 201H × 430D Knob,terminal not included
  • Weight 27kg

Finish: Silver alumite and bake coating

*The input impedance of this unit is 2.5kΩ. Drive with a device with an output impedance of 500Ω or less.

*Carbon plate GM70 is mounted for normal products, but metal plates are also available as an option. Please inquire about the price.

*Changes in specifications, design, design, price, etc. may be made without prior notice.