SW1X Audio Design Logo Circle Transparent
MPA IV Mono Power Amplifier Monoblock

SW1X Audio Design™ MPA IV “Aurora”

Performance Level 3/4/5
2A3 DHT Valve Mono Power Amplifier


MPA IV is a Pure Class A, Zero Negative Feedback, Directly Heated Triode, Fully Valve Rectified, Single Ended, 3 Gain Stage, Interstage Transformer coupled, Mono Power Amplifier.

The 2A3 Triodes in combination with 6V6 triode connected driver tubes provide a perfect balance between grunty power delivery & refined sound signature.

The output valves are de-coupled by Interstage transformers and driven by 6V6 power valves to enhance the sophisticated sound of the 2A3 triodes with powerful & grungy character of the 6V6.

Combined with the finest Materials & Components, MPA IV is refined & musical sounding, especially when combined with high sensitivity speakers (96dB/W/1m sensitivty is recommended).

MPA IV Mono Power Amplifier Monoblock

SW1X MPA IV Monoblock

SW1X Audio Design™ MPA IV Mono Power Amplifier Features:

  • Specially Selected and Harmonically Matched Component & Material Quality
  • Single Ended, absolutely Zero NFB, Class A, Directly Heated Triode Valve Power Amplifier
  • 6V6 Valve Driver/6J5 input Stage driving the 2A3 DHT Valves
  • Interstage Transformer de-coupled, 3 Gain Stage Design
  • Hybrid Point 2 Point Hardwiring Technique for the most consistent production results
  • Internally wired exclusively with our SW1X Magnum, Genesis and Opus conductors
  • SW1X Audio DesignCustom Designed Copper wound Super HiB DC Core (50 Watt) Signal Output Transformers
  • Mono, Directly Heated Double Diode Valve Rectified B+ Power Supply
  • Orient grain M6 EI core mains Transformers & Chokes
  • Valve rectified Fixed Bias Power Supply


Tube Compliment:  2 x 6J5, 2 x 6V6, 2 x 2A3, 2 x 5U4G, 2 x 5Y3


MPA IV Aurora is avaiable in 4 Versions with following output transformer (OPTs) specifications:

  • Standard : SW1X Audio Design all Copper wound, orient grain M6 EI Core OPTs
  • Special :  SW1X Audio Designall Copper wound Super HiB DC Core OPTs
  • Classic : SW1X Audio DesignCopper/Silver Windings, Super HiB DC Core OPTs
  • Signature : SW1X Audio Design™ Silver/Silver Windings, Super HiB DC Core OPTs

MPA IV Monoblock Versions


SW1X Audio Transformers

Optional Extras

  • Fully Hardwired Tube Output Stage on the Bakelite Board
  • Fine Silver Hardwiring of the Bakelite Board




Single Ended, Class A, Zero NFB, Output Power (W): 4, which sound at least like 30 Watts and the dynamic delivery feel like 300 W

when paired with with High Sensitivity Speakers (min 96dB/W/1m is recommended)

Input Sensitivity (V): 1

Input Impedance (Ohms): 100K

Output Impedance (Ohms): 4 & 8

Max Power Consumption (W): 200

Output Noise, Unweighted (mVrms): < 0.5

Dimensions (without tubes and feet): Height (mm) 200 x Width (mm) 250 x Depth (mm) 440

Weight (kg): 46 (pair)

SW1X Integrated Amplifier Products Overview

Note: Due to SW1X Audio Design’s ongoing research and development process, specifications are subject to change without notice

Products Price List


Related Products

Translate »