ST-150

This stereo amplifier delivers over 150 watts per channel (300 watts total stereo output), combining exceptional musical clarity with abundant power within a compact chassis. Hand-built by skilled artisans using premium components, the ST-150 is VTL’s high-value, high-power stereo tube amplifier. Its signature sound—fast, clean, and musical, with powerful bass—is driven by 6550 vacuum tubes. These tubes excel in both triode and tetrode modes, offering wide dynamic range and rapid transient response, making the amplifier an ideal match for compact electrostatic speakers and dynamic speakers with moderate current demands. VTL is a standout performer when it comes to midrange quality and high-frequency clarity. In triode mode, this amplifier is best suited for speakers with a sensitivity of 92dB/1W/1m or higher.
High-energy storage power supply >200 Joules
VTL proprietary output transformers
Ultra-low noise, utilizing a specially designed grounding scheme.
Switchable between tetrode and triode modes
150 watts per channel in tetrode mode
70 watts per channel in triode mode
Uses four 6550 tubes per channel, with individually adjustable bias for each tube.
Uses audiophile-grade film and foil capacitors in the signal path.
Features an extruded aluminum front panel with a luxurious, modern aesthetic—available in black or silver.

Vacuum Tube Complement 8 x 6550, 2 x 12AT7, 2 x 12BH7
Output power
Tetrode: 120W, Triode: 60W
20Hz – 20kHz <3% THD Into 5Ω
Input sensitivity @ 150W 100V = 0.880V; 120/240 = 1.0V
input impedance 130KΩ
Output Load Range 2Ω – 8Ω
S/N Ratio -95dB, 120Hz
Power Consumption Idle = 240W, Full Power = 800W
Primary Mains Fuse Rating 100V = 15A Ceramic Slo Blo, 120V = 15A Ceramic Slo Blo, 220/240V = 8A Ceramic Slo Blo
B+ Fuse Rating 1A fast acting ceramic 600V
Dimensions W x D x H 19 x 12 x 9 inches (48 x 30 x 23 cm)
Weight 85lbs (38.6Kg), 110lb (50Kg) packed