The GP-100 is a guitar preamp/processor that emulates the characteristics of tube amplifiers. The GP-100 is a single rack space unit that delivers 20-bit A/D conversion and 18-bit D/A at a sampling rate of 44.1kHz. It can retain up to 400 memorized programs including 200 factory presets and another 200 user customizable presets. The rear panel offers input and phones connections in addition to a pair of send and return loops and two sets of stereo/mono outputs.
All of the preamp parameters can be edited with the front panel knobs, just like an analog unit. There are a variety of available algorithms used to create effects like intelligent pitch shifting, slow gear, and feedbacker. Up to 16 simultaneous effects can be used at once. One can even control the "order" in which the effects are chained together.
The unit is MIDI accessible. The send, return, input, and output levels can be configured and stored in any of the patches for instant retrieval. There are also control jacks for switching external effects units on or off. These settings can be stored within patches as well.
The GP-100 was introduced by The Roland Corporation in the 1990's.