Audio Research VT200
Price unknown (around 1998)
Commentary
This tube type stereo power amplifier was developed as the highest model of the VT series.
The unique output transformer also supports ultra-linear connection and cathode feedback to ensure extremely low drive impedance and highly efficient and stable operation.
A highly reliable large beam tube 6550C is carefully selected for the power stage. The 6550C has a 4-parallel push-pull configuration with 8 left and right channels for a total of 16 channels. Therefore, the output impedance is sufficiently low, and by reducing the number of turns of the transformer, an excellent wide range and constant loss are simultaneously realized.
The signal system has a balanced configuration for all stages. It is equipped in the input stage with a constant current source, the shortest signal path, and the LR independent dual monaural configuration to enhance the total perfection.
A 3-speed -speed silent fan in the center of the chassis to properly cool the vacuum tubes and assist in stable operation when needed.
There is no change in load condition or input sensitivity when either one balanced or one unbalanced input is used.
The impedance of this input circuit is set so that it can be used with either a tube type or a semiconductor type amplifier, so that there is no mismatch when a semiconductor type channel divider is connected.
Model Rating
Type | Stereo power amplifier |
Rated output | 200W + 200W (continuous, 20 Hz to 20 kHz) |
Output bandwidth | 12 Hz to 120 kHz -3dB |
Total harmonic distortion factor | 1% (1 kHz, 200W) 0.01% or Less (1W) |
Frequency characteristic | 0.5 Hz ~ 200 kHz -3dB (1W) |
Input sensitivity | 2.5 Vrms (balanced / unbalanced) |
Input impedance | Balance : 200k Ω Unbalanced : 100k Ω |
Output terminal | 1 Ω, 2 Ω, 4 Ω, 8 Ω, 16 Ω |
Damping factor | About 11 |
Signal-to-noise ratio | 109 dB (at IHF, input short, rated sy passing power) |
Slew rate | 25V/ms |
Rise time | 1.5ms |
Vacuum tube used | 6550C : matched pair 8 pieces 6922 : 10 pieces |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption | 680W (No Signal) 1,200W maximum |
External dimensions | Width 483x Height 276x Depth 638 mm (Including Handle) |
Weight | 46.5 kg (Body) 58.3 kg (when packed) |