MU-4 EVO is stereo integrated amplifier supporting KT-120 or KT-88 in the output stage. Output tubes work in Push-Pull and fixed bias mode with moderate 8dB negative feedback. It yields up to 70 Watts of power per channel and vivid, very dynamic sound. Biases of output tubes pair in each channel are maintained in exact symmetry by specialized servo. As a result harmonic distortion, noise and hum are effectively eliminated. Output transformers work in ultra linear mode for harmonic distortion reduction. Huge 400W toroidal transformer guarantees high margin of spare power supply for amplifier.
Easy power tubes bias regulation. Tiny switch on the rear side changes volume bar into precise miliammeter. Bias is setup only for one tube in pair. The second is adjusted automatucaly by specialized servo
Power frequency response +0dB/-0.25dB: 20Hz-20kHz @70W
Frequency response +0dB/-3dB: 10Hz-70kHz
Nominal Power at THD=1%: 2x70W (KT120) 2x60W (KT88)
Voltage gain @4/8Ω: 31/35dB
RMS Noise A-weighted, max power: -75dBV
THD+N @1W : <0.05%
Damping factor : 2.5
Speaker outputs: 4Ω, 8Ω
Tubes: 4xKT120 (or KT88 or 6550), 2x6N1P, 2x12BH7
Dimensions (W/L/H): 43,5/43,5/23,5 cm
MU-2 phono stage uses J-FET transistor in parallel with 6922 tube in input stage. Together with 6922 tube second stage and MOSFET as source follower 56dB amplification factor was achieved. In practice it fits 0,2mV and higher voltage MC carts and all Moving Magnet (MM) carts. Thanks to advanced 240V stabilized power supply the sound of MU-2 is really good: low hum and noise much lower than generated by vinyl record itself. Side to side comparison to transistor preamps was positive for MU-2. MU-2 is more dynamic and neutral. When additionally pure “analogue” design will be taken into account then vinyl record listening satisfaction is guaranteed. Front panel was made of polished glass. MU-2 chassis was made of polished acid-resistant stainless steel. Power supply module together with toroidal transformer were separated from the rest of electronics by additional metal shield.
Frequency response: +0,15dB/-3dB: 10Hz-70kHz
RIAA curve accuracy in band 20Hz-20kHz: +/- 0,25dB
MC/MM gain: 56/43dB
RMS Noise A-weighted (MC, Input shorted): -80dBV
THD, Output=0dBV: <0.05%
IMD, Output=0dBV: <0.03%
Crosstalk MC: <-73dB
MM input impedance: 47kΩ/120pF
MC input impedance: 50,100,200,500,1000Ω
Input/Output: Unbalanced 2xRCA
Tubes: 2x6922EH (or 6DJ8, ECC88, E88CC)
Dimensions (W/L/H): 21/35/11 cm
“I thought about luxury when I saw Muarah products for the first time. Design, finish, materials used, or discreet reference to the luxurious Maserati brand, leave no doubt that we are dealing with the highest quality products (…) The sound of the MU-2 is big, it is saturated with chocolate brownie, which reminds me rather well, which is why I allow myself this comparison. His interpretation, like a good conductor, allows you to easily track the music, because the equipment does not lose its thread even for a moment and each instrument has its place here…”
Hi-Fi Choice issue 11/2016: MU-4 amplifier review verdict:
LIKE: Vivid and saturated presentation. Musicality and effortless rhythm control. Contour bass – detailed and accurate as in solid state constructions. Beautiful design.
DISLIKE: Neutrality not ideal but that's not a point here.
OVERALL: Against other tube amplifiers unusual industrial design is outstanding as well as unlimited sound. Muarah has it's unique character able to show sound beauty from incandescing tubes.
Hi-Fi Choice issue 7-8/2016: Mr.White turntable & MU-2 phono review verdict:
LIKE: Excellent highs and well arranged sound stage, full bodied, contour bass, very high resolution in mids
DISLIKE: preamp tubes LED backlight, sound performance limited by accompanied MM cart
OVERALL: very well thought out product set in two available colour versions. Vinyl collection listening pleasure guaranteed for advanced audiophiles.Value for money 4Build quality 5Features 4+Overall