With optical circuitry based on the classic amp tremolo circuits of yesteryear, the Ultrem Optical Tremolo takes the tone of those legendary units and adds a variety of new and useful control features that set it apart from any other stompbox on the market.

With the Ultrem several types of tremolo and volume effects are available including oscillator-controlled Tremolo and manually-controlled Volume. Rate of the Tremolo can be controlled via tap tempo, the unit's front-mounted Speed control, or an optional expression pedal. Dual outputs allow panning of the Tremolo effect between two amps or for use as an amp selector/blender in manual Volume Mode. Depth and Saturation controls allow for precise control of the degree and tonality of the effect as well as for use as a great-sounding Overdrive unit when the oscillator is disengaged.

At the heart of the Ultrem is Guyatone's proprietary CPU controller which allows for quick selection of the Ultrem's primary effect function. Six Effect Modes are easily accessible from the unit's front panel, and each Effect Mode features a Sub-Mode that can be accessed with a quick press of the Control Footswitch. If that wasn't enough, the last two Modes also feature Bonus Modes that allow for manual selection of the oscillator Waveform via an external expression pedal.

MPN: GST-C04
UPC: 838120001832

- WAVE TAP – Functions as an oscillator-controlled Tremolo with rate determined by tap tempo function of Control Footswitch.
- MOMENTARY WAVE – Functions as an oscillator-controlled Tremolo when Control Switch is depressed and held – releasing switch disengages the effect. Rate is determined by unit's Speed control.
- PEDAL VOLUME/WAVE - Main Mode varies output Volume using the optional Expression pedal or functions as an oscillator-controlled Tremolo in Sub-Mode. If set to Pan On, Ultrem can function as an amp selector/blender in Main Mode.
- PEDAL DEPTH & WAVE TAP - Allows user to vary the Depth of the effect by using an optional Expression pedal, and also to adjust speed of Wave Tremolo by tapping tempo, instead of using pre-set controls.
- PEDAL SPEED1/TOUCH – Main Mode varies the speed of the Wave Form oscillation with the optional Expression Pedal over a range of 70-1000 mS. In Sub Mode the unit functions as standard Tremolo.
- PEDAL SPEED2/TOUCH – Main Mode varies the speed of the Wave Form oscillation with the optional Expression Pedal over a range of 70-4000 mS. In Sub Mode the unit functions as standard Tremolo.