Power Amplifiers

Mystere pa21 Stereo Tube Power Amplifier



Durob Audio is a company in the Netherlands that markets PrimaLuna tubed audio components, including integrated amplifiers, power amplifiers, and a CD player that has a tube-based clock. It also has a discrete output stage with triodes running in pure Class A. Conventional CD players use op-amps in the output stage. Although the tube output stage and op-amp output stage sound different, one doesn't necessarily sound "better" than the other, although tubeophiles would all opt for the "better". We reviewed the PrimaLuna DiaLogue Two integrated amplifier in December, 2009.

With the introduction of Durob Audio's Mysterè line, we now review the Mysterè pa21, which is a 55 watt per channel stereo tube power amplifier. The Mysterè line goes beyond the PrimaLuna line with larger transformers, more power supply capacitance, and an auto-bias circuit that lets the consumer choose between using KT88's or EL34's as the output tubes. Trying different tubes is one of the things that makes tube products fun, and those who participate in this activity are called "tube rollers".


  • Design: Stereo Tube Power Amplifier, Push-Pull, Class AB
  • Power Output: 55 Watts x 2 into 8 Ohms
  • Tube Compliment: Four 6SN7, Four KT88
  • MFR: 9 Hz - 52 kHz, ± 1 dB at 40 Watts Output
  • THD+N: 1% at 55 Watts Output
  • Input Impedance: 100 kOhms
  • Inputs: RCA
  • Outputs: Five-way Speaker Binding Posts
  • Dimensions: 8" H x 16.75" W x 17" D
  • Weight: 60 Pounds
  • MSRP: $2,995 USA
  • Mystere USA