Features WINNER - 1999 EM Editors Choice Best Preamp The VT-737SP features a higher-performance microphone input transformer with +48v phantom selection. Instrument DI high source input with jack located on front panel. Balanced line input, discrete high-level Class A. The opto-compressor features a minimum signal path design with twin Class A vacuum tube triodes for gain matching. Description Product Description acuum tube triode signal path, transformer balanced microphone input, high-voltage circuits for maximum headroom to +30dB, low noise -92dB, internal discrete power supply with toroidal transformer, soft-start tube life extender, stereo link for compressors, all discrete Class A equalizer with musical passive filter design, sealed silver relays for signal routing, large control knobs with professional conductive plastic potentiometers, VU meter for output level monitoring and compressor gain reduction.