The brand new QUANTUM QL amplifiers in the ESX Portfolio are technically the small siblings of the QE models. Ideally, they can be used where the installation space is very tight. They are also emission-free and, like the large QE models, have the finest Class-D technology on board, which leaves nothing to be desired in terms of performance, sound quality and setting options. The optical appearance and dimensions the QL models share with the XE-DSP amps and the X-DSP processor, so that the combination of these devices enable high-quality DSP systems with a lot of power. The QUANTUM QL models are also coming with the space-saving remote control.


  • Advanced Class D technology with very high efficiency
  • Selected and audiophile tuned components
  • Massive aluminum heat sink
  • Heavy lateral die-cast parts
  • High Level Inputs with Error Protection System
  • Auto Turn-On, Start/Stop Ready
  • MOSFET PWM-Power Supply, 3-way Protection Circuit
  • Compact Bass Remote


  • 4 x 100/170 Watts RMS @ 4/2 Ω
  • 2 x 340 Watts RMS @ 4 Ω bridged
  • HP 50-5000 Hz (CH1/2), HP 10-500 Hz (CH3/4)
  • LP 50-5000 Hz (CH3/4), Copy-Mode CH3/4 > CH1/2
  • Bass-Boost 0-12 dB, Bandpass Modus, Input Mode
  • High Level Inputs, Auto Turn-On Function
  • Compact Bass Remote
  • Dimensions: 226 x 43 x 120 mm
  • Efficiency up to 86%


This item can be back-ordered.

ESX Audio QL600.4 Four Channel