VTL MB-300

The amplifier features a large capacitor bank in the power supply, suggesting a need for a variac for safe startup. The MB-300 has test points and a trimmer for bias adjustment, with some models potentially offering internal biasing procedures. Early versions of the MB-300 had a switch and meter on the front panel for bias adjustment, while later Signature models might have an internal adjustment. The MB-300 was later updated to the MB-450 Signature model, with cosmetic changes and an additional power supply for the driver stage, while maintaining the same power output.

ype: Tube Monoblock Power Amplifier Power Output: 300W (no load specified) Tube Complement: 12AT7, 12BH7, and 6550 (x8) Bias: Fixed-biased at class-A1 Power Supply: 550V with 1650uF of storage capacitance Input Sensitivity: 775mV RMS Source Impedance: 0.1 ohm Dimensions: 19" W x 10" H x 22" D (estimated from similar models) Weight: 75 lbs each