EWA M-50 class A power amplifier, Colin Wonfor. front

EWA M-50 Power Amplifiers: Stereo / monoblock pair


M50 power amplifier: 


The M-50 is a power amplifier for all occasions, with plenty of class A heft and control but a delicate musical touch. Extremely capable, even with tough loads (ribbon speakers etc), but equally at home driving something extremely sensitive.

  • M-50 Power:

    Input: 22KΩ

    Full power @1V = 50W RMS into 8Ω

    Power Output:​

    • 55W/8Ω

    • 100W/4Ω

    Peak current >64A

    DC offset < 5mV

    Open input noise < 2mV

    Bandwidth: 5Hz to 200KHz ±1db

    DF: >500 (dynamic)

    Standby: under 1W

    Maximum: 40W


    The output stage is run in A/B and has a SECA drive stage. Four complementary pairs of transistors rated at 25A 125W, driven by 15W 140MHz transistors. The SECA driver is running at 3W. Extremely fast RF transistors are used to increase stability in the amp under non- normal loads i.e. no resistive a speaker with a wicked load line character. 


    Power supplies can be made for most countries of the world except those on DC.


    IEC power inlet fitted as standard.


    BUILD TIME: Approximately two - four weeks.

  • Taking the incredible EWA M-50 circuit and bridging it, running two mono amplifiers instead of a stereo unit; we introduce to you the EWA M-50 monoblock pair. Another mad creation by Dr Wonfor!

    Recognizable as the same classic design as the M-50, but built as a true dual differential balanced amplifier with incredible power reserves. Rated (conservatively) at the same basic output as the stereo M-50, the monoblock versions have a much stiffer power supply and will merrily double their power output as impedence haves - all the way down to one ohm.

    What you are getting here is almost M-100 performance in a much more compact package.

    Available as standard with true balanced input.


    IEC power inlets.


    Build time: Approximately four-six weeks.

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