Controls

• Drive and Gain - These controls set the gain of the CMOS distortion stage. On the original amp, a single, dual-gang potentiometer was used for this control, but we decided to split it into two independent controls for extra versatility. With so many different sounds available, it's impossible to give a description of their behaviour. Experiment and see what you like!
• Bass, Mid and Treble - 3-band active tone control with a very large +-15dB sweep range. Don't be afraid to visit the extremes, as the circuit drastically changes its behaviour at the top and bottom range of motion of these controls.
• Volume - Controls the output signal amplitude.
• Tight - Tames the bass frequencies for a slightly grittier but brighter sound.
• Bass/Lead - Switch between "Beta Lead" and "Beta Bass" mode. A handful of components are switched in and out, but these have a huge impact on the sound, resulting in a bassier, beefier sound (Bass), or a thinner, brighter and more aggressive sound (Lead).
• Active Switch - Engages or bypasses the pedal with a relay (true bypass).

The original

The Sunn Beta Lead is known for two things. First, its incredible deep bass and fuzzy sound that made it so popular. Second; it's ridiculously loud.

Utilizing an integrated circuit chip designed for digital logic circuits, the engineers at Sunn Amplification designed an amplifier based on the concept of abusing a CMOS logic inverter and contorting it into a guitar amplifier. The front panel stated the phrase "Digital C-MOS Technology", and while the chips used to generate the disortion were in fact designed for digital logic circuits, they were being used to process an analog input signal, something they were never intended for.

The result was surprisingly pleasant, and the Beta Lead became one of the most iconic solid state amps ever built. Used by Kurt Cobain and The Melvins, among many others, it has an extremely wide sonic palette. This means that for those unfamiliar with the amp, it can sound straight up awful, if you don't know how to set the controls. Thankfully, it has numerous sweet spots, which range from bluesy edge-of-breakup, to rock and roll, to heavy metal and fuzzy doom.

Features

• True Bypass with Relay switching.
• Soft-touch footswitches.
• Internal voltage-boost mechanism ensures circuit runs at same voltage as the original amp.
• Rugged 16 gauge (1.6mm) steel enclosure with textured powder coat finish.
• Solid aluminium knobs.

Technical Specs

• Power Requirement: 9V DC, 180mA
• Power connector: 2.1mm center-negative barrel jack
• Dimensions: 145mm (W) 108mm (D) 61mm (H)
• Dimensions (with packaging): 185mm (W) 130mm (D) 70mm (H)