The Seymour Duncan SFX-04 Twin Tube Mayhem is a distortion pedal with a high-quality guitar preamp that includes a built-in boost. Using a duo of premium, mil-spec, subminiature, USA-made Phillips-Sylvania 62051 pentode tubes, the Seymour Duncan Mayhem is a great effect pedal for old-school metal, new metal, thrash, death, and doom.

The Twin Tube Mayhem pedal has a high plate voltage and 100% vacuum tube signal path that allow the tubes to operate at their full potential and provide maximum dynamic range. The SFX-04 Mayhem pedal achieves additional gain with a high-voltage, low-noise, and discrete Class A input stage. The solid state input stage increases the resistance of the Mayhem stompbox to microphonic feedback, resulting in maximum dynamic range, the most gain, and the heavy tone you'd expect from a great tube preamp voiced for metal.

The Seymour Duncan Twin Tube Mayhem distortion pedal also features user-selectable 4dB or 8dB boost for pre-setting rhythm and lead levels. The Mayhem distortion pedal uses true bypass switching and has a fully encapsulated toroidal transformer for quiet operation. Its rugged, heavy-duty steel chassis provides exceptional durability.

Seymour Duncan SFX-04 Twin Tube Mayhem Distortion Guitar Effects Pedal Specifications:

• Gain:
• Before Level Compensation 97 dB
• After Level Compensation 71 dB
• (Measured at 1 KHz)
  
  Nominal Output Level 0.25 Vrms (-10dBu)
• (Measured with 100mV 1 KHz input signal and all controls set to 12 o'clock)
  
  Max. output level before clipping 5 Vrms (16dBu)
• (Measured with gain set at 50% and all other controls set full up and boost footswitch set to 8dB)
  
  Input Impedance: 100K ohms
• THD @ 100mV RMS output .5%
• Noise @ Output 4mV (< 3dB hum content)
  
  Boost Footswitch Gain:
• Two selectable boosts, 4dB and 8dB.
• No effect on tone, just increased level.
  
  Active Equalization Section:
• Bass Control: 126 Hz, Q = 1.5, Gain = ±12dB
• Midrange Control: 596 Hz / 1389 Hz, Q = 1.5, Gain = ±12dB
• Treble Control: 2.93 KHz, Q = 1.4, Gain = ±12dB
  
  Power Consumption 11W