The 737 SP combines a tube pre, optic compressor, and a 4 band EQ. Looking at the front panel starting from the left, there is a preamp gain, instrument input and input control knobs that give an option of line, instrument, or mic.
The VT-737sp's opto-compressor features a minimum signal path design with twin Class A vacuum tube triodes for gain matching. The optical attenuator acts as a simple passive level controller. Full dynamic control from soft compression to hard- knee limiting can be achieved with threshold, ratio-compression, attack and release controls plus gain reduction selection on the large VU meter. Special spectral control including de-ess is available with the dual sweep mid EQ to side-chain switch. The VT-737sp's EQ section can be flipped pre or post the opto-compressor via a front-panel switch for alternate effects and tone shaping. Two VT-737sps can be linked via a rear panel link cable for stereo tracking. The compressor bypass is a sealed silver relay for the most direct signal path.
