Amp Type: Tube Chassis Material: Aluminum Rectifier Type: Silicon Diodes Rectifier Tubes: n/a Variac Power Switch: n/a Preamp Tubes: 5x Mesa 12AX7 Power Amp Tubes: 2x Mesa 6L6 Bias Switch for Alternate Power Tubes Types: n/a Maintenance Free Fixed Bias: Yes Wattage(s): Quick Reference 5, 25 or 50 Watts - Channel Assignable - See Power Amp Details for more information Built-In Power Amp Attenuation: n/a Power Amp Details (Class & Wattage): Mesa's Patented Multi-Watt (Patent 7,602,927) Power Amp, featuring Duo-Class (Patent 7,173,488) technology, provides three power and two operating-class options that are channel assignable via two 5/25/50 Watt Power Switches: Choose 1 power tube operating in pure vintage Class A (single-ended), producing 5 Watts - 2 tubes running in pure Class A, Push-Pull, producing 25 Watts or 2 tubes operating in time honored Class A/B power, producing 50 Watts Convection or Fan Cooling Convection Number of Footswitchable Channels (or Modes): Two Channels Number of Style Modes: Four Number of Style Modes Per Channel: Two Types of Style Modes Per Channel: Ch. 1 = Clean or Crunch Ch. 2 = Blues or Burn Channel Controls: Each Channel features Independent 2-Position Style Mode Switch, 5/25/50 Watt Multi-Watt Switch, Gain, Treble, Mid, Bass, Footswitchable Reverb, Master and Footswitchable or Auto-Assignable Contour Depth Control Graphic EQ and/or Contour Selectable 5-Band Graphic EQ and Contour (Footswitchable, Channel Assignable or Off) Reverb / Effects & Bypass Options Footswitchable, All-Tube, Long Spring Reverb with Independent Channel Controls Effects Loop & Bypass Options: Fully Buffered FX Loop Global Output Level Control: n/a Global Solo Level Control & Bypassable Options: Yes (Over each channel when activated) True-Bypass Options: n/a Tuner Output: n/a External Switching: Jack Options and/or Midi External Switching Jacks for Channel 1/2, Reverb, EQ & Solo Speaker Outputs: One 8 Ohm and Two 4 Ohm Cabinet Simulation: Direct Live/Recording Output Slave Output: n/a