Established 1968   01603 627010

Available at Martins Hi-Fi


Our price
Image of VTL MB450



Music lovers have long admired the VTL MB-450 Signature monoblock amplifier for outstanding performance at a fair value. The new Series III version of the long-standing MB-450 platform features a complete re-working of the entire signal path. Upgrades include a fully balanced differential input stage driving a differential phase splitter and a lower impedance push-pull output stage with a dramatically improved, fully balanced and enhanced interleaved and coupled output transformer. VTL's innovative engineering brings the legendary sonic performance of the venerable 450 Signature platform to even greater heights.

The new MB-450 Signature monoblocks gain further sonic benefits with a shorter, faster and fully balanced negative feedback loop, with zero global negative feedback. The negative feedback loop completely eliminates ringing and requires no capacitor compensation to maintain critical phase integrity and information. The result is an amplifier that remains stable even under the most demanding loads.


Feature List:

  1. Fully balanced differential circuit – even single-ended signal produces balanced signal at output.
  2. Re-designed fully balanced differential input and driver stages for increased signal swing, bandwidth and stability.
  3. Zero global Negative Feedback.
  4. Shorter, faster feedback loop for greater tonal control without phase shift.
  5. Improved handling of loudspeaker loads for greater signal stability.
  6. The amplifier is unconditionally stable, without the need for capacitor compensation.
  7. Tube like JFET-type current source for lower sonic impact in single-ended mode.
  8. Lower impedance output stage for improved loudspeaker control.
  9. Dramatically increased interleaving and coupling in the balanced VTL proprietary Signature output transformer, for wider bandwidth and zero ringing.
  10. Variable user-adjustable DF feedback control to vary output impedance and damping factor for optimal matching to speaker load.
  11. Software microprocessor controlled
    · Tetrode/Triode Switchable
    · Auto Bias, Fault Sensing
    · Current in-rush limiting
    · Standby Mute function; with reduced tube current for increased tube life.
  1. 450 watts per channel in tetrode; 200 watts per channel in triode.
  2. Uses eight 6550C or KT-88 tubes per monoblock.
  3. Adjustable regulated screen supply for stable operating point; discrete regulated input and driver supply for greater signal resolution and tonality.
  4. Adjustable precision-regulated bias supply for greater signal resolution and noise rejection and improved isolation from mains supply variations; output operating point does not change with AC power fluctuations.
  5. Improved Autobias and fault sensing system to operate in fully balanced differential mode; amplifier is fully protected against output tube failure; no need for precision matching of output tubes.
  6. All premium Mundorf silver oil caps in signal path
    Film bypass of power supply caps for greater HF resolution.
  7. Extruded aluminum front panel with luxurious, modern look – black and silver options available
    Rack mountable.
  8. Rigid construction and improved ventilation for lower operating temperature.
  9. Factory upgradeable from Series II.

MB-450 Series III Signature Monoblock Data Specification

Vacuum Tube Complement

8 x 6550C or KT-88, 1 x 12AT7, 1x 12BH7

Output Power
20 Hz – 20 kHz into 5 ohm load

Tetrode = 425W
Triode = 225W

THD 20Hz - 20kHz @ 450W Tetrode
THD 20Hz - 20kHz @ 200W Triode


Input Sensitivity

Variable between 1-2V, depending upon DF setting

Input Impedance

45K Ohms

Optimum Load Range

5 Ohms

S/N Ratio @ 450W Tetrode
S/N Ratio @ 200W Triode

-110dB, 120Hz

Power Consumption

Idle = 300W
Full Power =1000W

Primary Main Fuse Rating

110/120V = 15A Ceramic Slo Blo
220/240V = 8A Ceramic Slo Blo

Input Fuse

110/120V = 1A Ceramic Slo Blo
220/240V = 1A Ceramic Slo Blo

Logic Fuse

110/120V = 1A Ceramic Slo Blo
220/240V = 1A Ceramic Slo Blo

B+ Fuse Rating

Plate Fuse - 2.5A Fast Acting 600V
Screen Fuse - 0.75A Fast Acting 600V


W = 18.5 Inches (47 cm)
D = 18 Inches (46 cm)
H = 9 Inches (23 cm)


93 lbs (42 Kg) unpacked
110 lbs (50 Kg) packed


Search by:

Martins HiFi

Terms & Conditions

Address & contact

Shop address:
85-91 Ber Street, Norwich, Norfolk, NR1 3EY
Opening Hours:
Monday to Saturday, 9am to 5.30pm
01603 627010

Get in touch

Stay connected

Sign up for the latest news and exclusive offers from Martins Hi-fi.


Please read our Privacy Policy