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.
Adjustable precision-regulated bias and screen supplies hold the output tube operating point constant even under AC and main power supply fluctuations, and stabilizes the critical power supplies yielding tonal stability and sonic integrity especially during complex, dynamic signal conditions.
Another new feature is a user adjustable Damping Factor feedback control that allows the user to adjust the amplifier’s output impedance by varying the amount of negative feedback. Impedance can now be precisely set to suit the listener’s taste, and to improve control of the loudspeaker loads to deliver best performance.
Specifications and Features:
- Vacuum Tube Complement: 8 x 6550 or KT-88, 1 x 12AT7, 1 x 12BH7
- Output Power:
- Tetrode = 425 watts
- Triode = 225 Watts
- 20Hz ‐ 20kHz <2.5% THD: Into 5 ohms
- Input Sensitivity: Variable between 1-2V, depending upon DF setting
- Input Impedance: 45K Ohms
- Load setting: 5 ohms
- Optimum Load Range: 4 - 8 ohms
- S/N Ratio: 450W Tetrode & 200W Triode: -110dB, 120Hz
- Power Consumption:
- Idle = 300 W
- Full Power = 1000 W
- Primary mains fuse rating: 100/120V = 15A Ceramic Slo Blo, 220/240V = 8A Ceramic Slo Blo
- Logic fuse: 100/120V = 1A Ceramic Slo Blo, 220/240V = 1A Ceramic Slo Blo
- Input fuse: 100/120V = 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
- Dimensions W x D x H: 18.5 x 18 x 9 inches (47 x 45.7 x 23 cm)
- Weight: 93lbs (42kg) per monoblock unpacked, 110lbs (50kg) packed