Bright Switch

Selects two levels (or none) of high-end emphasis, pre-tone stack.

Grind Switch

Input sensitivity boost. Adds "grind" or tames hot pickups. Great for single-coil types.

Tremolo, Frequency and Intensity

From slow, fat and throbbing, to a faint flutter.


The reverb tank is an Accutronics long-spring unit for deep, lush reverb, controlled with a Hi-Lo drive switch, plus the Mix control to best suit the music and volume level.

Clean Switch

Preamplifier output control. Two levels of attenuation. Controls the amount of signal hitting the phase inverter tube. Used mostly to control levels in the signal path, the Dynamic 2040 allows the player to adjust the input sensitivity, preamp gain, preamp output level, power amp gain and power amp output. Using three positions toggle switches makes this degree of control easy and more repeatable.

Voicing Switch

Selects three midrange points, bypass of voicing circuit, and bypass of entire tone stack.

Tone Control

Rotates from thin (counter-clockwise) to fat (full clockwise). This knob is engaged in positions 1 through 4 of the Voicing Switch, and disengages in position 5 (full right).


Post-Phase Inverter type master control, sounds best in the last 1/3rd rotation. For more attenuation, use the PowerStep switch on rear panel.



This feature is a very useful and novel way to reduce power in such a way as to maintain tone quality at lower power levels by reducing plate voltage, while maintaining bias settings which a Variac cannot do. The three levels are 100%, 50% and 10%. A perfect feature to set up your amp for venues ranging from home to the large club. Extremely effective when used in conjunction with the front panel gain stage controls.

Parallel and Series

Sometimes combining speaker cabs can be difficult to match to the amp because the impedance (resistance) of the cab has to be matched to the impedance of the output transformer. Two 16 Ohm speaker cabs can be plugged into the Main and Parallel output jacks to create a 8 Ohm match to the output switch. Similarly, Two 4 Ohm cabs can be plugged into the Main and Series jacks to create an 8 Ohm match to the output switch, and two 8 Ohm cabs can be plugged into the Main and Parallel jacks to create a 4 Ohm match to the output switch.

Effects Jacks

Reverb, Tremolo and Boost. These are RCA type jacks, as in vintage blackface and silverface amps. Any cable with male RCA plugs, such as hi-fi audio connector cables will work. Optional footswitch boxes with two or three switches will allow controlling Boost, tremolo and/or reverb.