Note: Not sold seperately * Used in Coolback 800 and custom solutions

NEW Product

Power Amplifier Module - 1kW+

HPA1K is an extremely powerful bipolar amplifier of classical front end design and a class H output stage with exceptional good current gain and low loss rail switch.

HPA1K consists of a differential cascode coupled input stage controlled by a current generator. The input stage is totally discreet to optimize for linearity and bandwidth. The voltage gain stage is also cascode coupled, which is differentially symmetric in class A, to achieve low distortion at high frequencies. The step driver is totally discret build and further iliminates spikes when switching rails. This power amplifier module is very powerful and yet it features low losses and very moderate idle power consumption.

HPA1K are decoupled at positive and negative supplies with polypropylene capacitors.

HPA1K has short circuit protection, thermal protection and rail fuses to prevent output device break down.

HPA1K features sonic excellence, constant low output impedance, low noise, low distortion and high reliability.

The maximum power output depends on voltage supply, heat sink and load conditions. Recommendations: Voltage supply of + / - 45V & + / - 90V, heat sink less than 0,4 K / W and minimum load of 2Ω.


  • Maximum power output: 350W (8 Ω), 600W (4 Ω), 1kW+ (2 Ω)
  • 4 high speed output power transistors
  • Low Loss MOSFET rail switch
  • Supply voltage +/-45V & +/-90V
  • Distortion : <0.08%
  • Frequency response: 5-20kHz (-1dB)
  • Slew rate : >40V/µs
  • S/N: >120dB
  • Gain: 23,5dB
  • Input impedance : 10kΩ
  • Input impedance : 10kΩ
  • Output impedance : <0.07Ω
  • Thermal protection above 80°Celcius
  • Mute control
  • Weight: app. 360g
  • Overall dimensions: 210mm x 85mm x 32mm

This is how Class H amplifier output stage switches: © Ground Sound * Products of Denmark