MB-125 Monoblock


Years of refinement have produced an amplifier of unparalleled clarity and musicality at its price. These space efficient monoblocks, sold in single monoblocks or in pairs, are an excellent choice for the two-channel as well as home theater systems. Using EL34 tubes that are known for their sweet top end and rich midrange, these monoblocks are best suited for planar and electrostatic speakers as well as highly efficient floor standing dynamic speakers.
MB-125 top view
MB-125 back view

Functionality features

  • High energy storage power supply >200 joules.
  • VTL proprietary output transformer
  • Tetrode/Triode Switchable
    • 100 watts per channel in tetrode
    • 50 watts per channel in triode
  • 4 EL34 tubes per channel with individual bias setting for each tube
  • Extruded aluminum front panel with luxurious, modern look – black and silver options available
  • Front panel comes with a window of thick smoked glass where you can see the glow of tubes


pdficon_smallMB-125 Data Sheet

Technical Specifications

Vacuum Tube Complement 4 x EL34, 2 x 12AT7
Output power
20Hz – 20kHz <3%
Tetrode: 100W, Triode: 50W
Into 5Ω
Input sensitivity 700mV
Input impedance 145kΩ
Optimum load range 2Ω – 8Ω
S/N Ratio -95dB, 120Hz @ 100W Tetrode or 50W Triode
Power consumption Idle = 100W, Full power = 300W
Primary mains fuse ratings 100/120V = 6A Ceramic Slo Blo, 220/240V = 3A Ceramic Slo Blo
B+ fuse ratings 0.75A Fast Acting Ceramic
Dimensions W x D x H 16 x 12 x 7 inches (40 x 30 x 18 cm)
Weight per monoblock
42lbs (22Kg) unpacked, 45lbs (25Kg) packed

VTL MB-125 Monobloc Amplifiers

…Few amplifiers have had the impact or had our reference system singing to the triumphant levels that the visually unassuming MB-125s have. Call it synergy, within the microcosm of my reference system, or call it all-round potential excellence in the audio world at large. One thing’s for sure – shopping at this price point and not trying the MB-125s is totally at your peril because, in the world of the high-end, the VTL MB-125 little monos are one hell of a bargain.

Read the full review here…

- Edgar Kramer, AudioEsoterica (Australia,) June 2013