SFX-03 - Twin Tube Classic Specifications Description – The SFX-03 is a two channel guitar preamp employing premium subminiature type 6021 vacuum tubes. The 6021 is manufactured to meet the stringent MIL-E-1 specification for reliability and is optimized to provide long service life under conditions of severe shock, vibration, high temperature and high altitude. The tubes are configured with a high voltage power supply for maximum dynamic range. True bypass capabilities are provided to allow uncolored feed-through. External dimensions: 7.50 X 6.62 X 1.96 in. (190 X 168 X 50 mm) Weight: 3.15 lbs. (1.43KG) Gain: Before level compensation Rhythm channel – 74dB Lead channel – 98dB After level compensation Rhythm channel – 52dB Lead channel – 76dB *Gain measured at 500Hz Nominal output level: Rhythm channel – 0.4 Vrms (-5dBu) Lead channel – 0.5 Vrms (-4dBu) *Nom. output level measured with 100mV 500Hz input signal and all controls set to 12 o’clock. Max. output level before clipping: 2 Vrms (+8dBu) *Max. output measured with all controls set fully up. THD @ 1 Volt RMS output: 3% Harmonic spectrum @ 1Vo: predominantly 2nd harmonic with minor amounts of 3rd harmonic @ > 20dB below. Noise @ output: Rhythm channel - < 1mV (< 3 dB hum content) Lead channel - < 8mV (< 3 dB hum content) *Noise measured with all controls set fully up and input shorted. Power consumption: 10.4 W