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Review of EWA M-50 Power Amp

Discussion in 'audio' started by Mark D, Apr 2, 2021.

  1. Mark D

    Mark D Member


    I recently inserted some EWA components into my system and thought a review would be useful to some.

    System prior to changes:
    PS Audio P12 PowerPlant AC regenerator
    Linn LP12 / Karousel / Radikal (Akurate) / Rubikon subchassis / Khan top plate / Chris Harban plinth
    (Makore wood) / Naim ARO (with sKale counterweight) / DV XV-1s cartridge
    Ryan Sound Lab phono stage (
    Mogami 2549 interconnects (1m)
    Ryan Sound Lab preamp
    Flashback RCA phono to XLR cable (1m)
    Naim NAP250 power amp (olive, fully serviced)
    NACA5 speaker cable (5m per side)
    Dynaudio Excite X38 speakers on DIY plinths
    All power cords are AV Options Cryo Tibia (Naim cords that have been cryoed)

    The listening room is 20' x 13.5" and the speakers are set up firing down the long axis using the golden ratio method. The room is acoustically treated and also has a dedicated radial power supply with separate ground

    1. NAP 250 replaced by EWA M-50
    2. Flashback RCA phono to XLR cable replaced by EWA IC-25 interconnect (1.2m)
    3. NACA5 speaker cable (5m per side) replaced by EWA LS-25 (4m per side)

    First of all, I must say that the service from Colin Wonfor and Alan Brown at EWA has been exemplary. I was able to talk to Alan and Colin by phone, and e-mails were answered promptly. I was initially deciding between the M-50 and M-100 amps, but Alan convinced me that in my room and with my system the M-50 would be all the amp I’d need. Also, Alan and Colin bent over backwards, forwards and sideways to solve a slight mains hum (through the speakers) from the M-50.

    Compared to the NAP250 the EWA M-50 is a revelation.
    From a Hi-Fi perspective:
    a. Perceived extended frequency response at both ends of the spectrum.
    b. In my system and room, the amp is easily the most neutral I’ve heard.
    c. Extremely open sound stage (width, depth and height) with precise imaging.
    d. More natural mid and high frequencies.
    e. Incredibly tight and deep bass, - and I do mean incredibly tight.
    f. Increased detail, attack and decay of notes, dynamics and timbre of instruments.
    g. The M-50 makes even poor pressings sound very listenable, - and believe me, I have some stinkers.

    From a musical perspective:
    a. Easier to separate musical strands and juxtaposition of tunes and melodies.
    b. Connection between listener and performers is increased.
    c. Many more moments that give me goosebumps.
    d. Simply a thoroughly enjoyable listen.

    I won’t go into the effects of the LS-25 and IC-25 as that has been covered in other posts, but I will say that I agree with almost everything written.

    Concluding comments:
    1. All of the EWA products mentioned are well built and well finished.
    2. Spurred by the improvements wrought by the items described above, a couple of days ago I replacedIC-25. In another thread Alan Brown commented that he thought the IC-25 were the cherry on thecake and not as big an improvement as changing to the LS series speaker cables. In my system I’d saythat’s a very large cherry.
    3. I have no affiliation with EWA apart from being a very satisfied customer.
    4. I’ve listened to many amplifiers from the cheap to the outrageously expensive. From what I can recall, some of the better ones sounded as neutral as the M-50 but somehow they didn’t inspire, - they sounded insipid and/or bland. The M-50 doesn’t fall into that trap, - it’s a toe-tapper.
    5. The threads on the LS-40 and LS-80 speaker cables have me wondering how much better they might be. I may be upgrading the LS-25 soon if money isn’t tight.
    6. If I had to sum up in one word what the EWA products have brought to my listening experience I’d say ‘Joy’. Lots and lots of extra joy from the music.

    Best regards,
    Mark Dunn
    Bettisdad, Billsie, nostromo and 8 others like this.
  2. hifinutt

    hifinutt hifinutt

    Thanks for write up , did you find a cause for the slight hum ?
  3. matfff

    matfff pfm Member

    Thanks Mark, very interesting.
  4. CJ14

    CJ14 Retired

    Yes I did it was caused as far as can I tell, remote from Texas, by mains borne noise, so I fitted a nice filter on the mains IEC . Here in London I had no problem the M50 was shhh silent.
    We are now on all product fitting filters, and on the Sib M50 a twin filter, because it has auto switch on and time out, and I thought clicks of fridges etc. might trigger it.
    Thanks you Mark for a truthful and plain write up.

    Best Col
    hifinutt likes this.
  5. iansr

    iansr pfm Member

    As the very happy owner of a M-100TS I’m not in the least surprised by this review.
    CJ14 likes this.
  6. ex brickie

    ex brickie pfm Member

    Thanks for the review @Mark D
    If you are upgrading from LS25 both @steveinspain and I found the improvement in the 80s over the 40s very worthwhile. Good luck!
  7. the caretaker

    the caretaker pfm Member

    What did you think caused the biggest change in your system ? The amp or the different cables? And did you try the new cables with your old amp?
  8. quickie

    quickie SE 'A' Class

    Many moons ago I remember comparing an olive Nap 250 to one of Colins amps (think it was an ID25 or 75)

    Enjoy :)
  9. Mike Reed

    Mike Reed pfm Member

    I'm a bit baffled here, as with a fully dedicated radial system, there should be no domestic interference or hum, esp. if put through a decent regenerator. Fitting a filter, to my mind, detracts from the benefits of a dedicated supply. Maybe sth I've misunderstood here but to me, improving the supply and filtering it seem to be at odds.
  10. Mark D

    Mark D Member

    Definitely the amp.
    The cables did improve the system with NAP250 but the amp was easil the biggest improvement.

    Mark D.
    CJ14 and the caretaker like this.
  11. Mark D

    Mark D Member

    Hi Mike,

    The cause of the hum was very difficult to pin down. It did not increase with volume, was present whether or not the amp's inputs were connected, and was present when the amp was plugged into different circuits in various rooms of the house (I tested with a small speaker in several locations). The house has no dimmers or fluorescent lights (all incandescent) and there are no wallwarts on the circuit. I have wi-fi but the nearest transceiver is over 25 feet away in a different room.

    Colin had to brutally abuse the amp with weird mains AC waveforms on his bench before getting even the slightest amount of 120Hz hum. It's an anomaly that I have to put down to an unknown local environmental oddity. The main thing is that it's no longer an issue.

    Mark D.
    CJ14 and Mike Reed like this.
  12. CJ14

    CJ14 Retired

    Watch out for new M50A with auto trigger. 18W Class A 50WRMS.
    quickie and Cereal Killer like this.
  13. 29mile

    29mile pfm Member

    As a fellow M50 owner I can only fully endorse Mark’s comments. It is a superb amp and when used with EWA cables ( I use LS40) it only gets better.
    Hats off to Colin and Alan at EWA for giving us the opportunity to simply enjoy our music in such a rewarding and pleasurable way !
    CJ14 likes this.

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