RAAL Requisite HSA-1b Headphone & Speaker Amplifier


Stefan says: This is bound to be the perfect amplifier for your SR1a. No conversion box, tailor-made by the makers of the SR1a – you get the idea!

Plus in the final version you will also be able to drive your regular dynamic, planar magnetic headphone and speakers.

I can wait to hear it. Per-orders can be placed now.

This is the updated HSA-1b! It is expected to ship with CE Certification beginning of July 2020! It will drive both Ribbon and regular headphone and speakers!

Available on backorder


HSA-1b (b for even better!)
& Speaker Amplifier

Direct Drive Amplifier For RAAL-requisite True-Ribbon Earfield Headphones and Regular Dynamic and Planar Magnetic Headphones!

  • Uncompromised Fidelity
  • Superbly Synergistic to the SR1a
  • Can Drive SR1a AND regular dynamic and planar magnetic Headphone (not as pictured below)
  • Output Switchable between Headphones or Speakers
  • 120V or 240V Voltage Select
  • Unbalanced, Single-Ended RCA Inputs
  • True-Balanced, XLR Inputs
  • Direct Drive for True-Ribbon Headphones and Conventional Speakers
FRONT Attention: this picture is not entirely correct: On the actual model you will find both a male and female XLR4 plugs for both the SR1a and a regular headphone.
Load Impedance:
0.3 Ohm – infinity
Output Power (one chanel driven) :
10W /8Ω, 20W/4Ω, 40W/2Ω, 55W/1Ω @ 1khz/sine
Ribbon Headphones Drive
2 x RAAL-requisite SR-1a
Freq. Response:
100mv/ in/sin. 15hz – 500kHz
Power Bandwidth:
10Hz(-1dB) – 100kHz (-2dB)
< 0,5% at 1khz
Signal to Noise Ratio:
Better than 90dB
Input Impedance:
40 kOhm
0,5V /40kOhm
IN1- 2 RCA, IN2 – 2 XLR
Max Power Consumption:
150W , without signal 25W
H 90, W 218, D 320mm (3.54 x 8.58 x 12.60 inches)
5,3kg (11.68 pounds)


RAAL Requisite