Shopping Cart


Your shopping bag is empty

Go to the shop

Boss GT-100 COSM Amp Effects Processor Multi Effects Unit w/ Power Supply


+ shipping

Up for sale, a Boss GT-100 COSM Amp Effects Processor in excellent condition and in perfect working order, complete with the original power supply. Recreating the meticulous details of vintage tube amp behavior, the GT-100 not only excels at cloning classic amps, but it opens up a whole new world of unimagined tones via the Amp Customize function.

The GT-100’s unique dual-LCD and eight-knob user interface provides fast access and intuitive control. There are no menus to navigate, and every function is instantly available. The tone-customizing functionality has been improved as well over previous models, with all patches, amps, and overdrive/distortions fully tweakable with the friendly graphical Tone Grid.

The Accel pedal offers a new dimension of expression, enabling control of multiple parameters simultaneously, as well as time-variant effects such as Feedbacker, S-Bend, Twist, and more. Another notable feature is the versatile A/B Channel Divider. This lets you assign different amps and effects to each channel, either for blending together, or switching back and forth with a footswitch. Going even deeper, you also have the ability to switch channels via playing strength or frequency range. With each channel capable of driving its own effects and amps settings, the range of tones is vast.

Available as a free download for Mac or Windows, Boss Tone Studio gives you an intuitive graphical interface for creating and editing effects patches from your computer via USB. The software also makes it easy to organize and archive patches, and to load them as needed for different gigs and recording sessions.

Cosmetic wear is limited to a few light scuffs and scratches on the enclosure. The graphics are pristine, and the original knobs are intact. The original power supply is included.

Features include:
  • Advanced COSM amps that model vintage classics and deliver highly expressive tones
  • Dual LCDs and panel knobs offer simple and intuitive operation, with direct access to every parameter
  • EZ Tone feature with graphical Tone Grid for constructing new patches, plus Amp Customize and OD/DS Customize functions for easily creating original sounds
  • Unique Accel pedal provides simultaneous control of multiple parameters
  • Powerful A/B Channel Divider for creating dual amp and effects chains that can be blended together or toggled by footswitch, frequency, or picking strength
  • Monophonic guitar-to-MIDI conversion from normal 1/4-inch guitar input
  • Enhanced USB audio/MIDI interface with multi-channel operation for flexible recording and efficient re-amping
  • Support for Boss Tone Studio editor/librarian for Mac/Windows and new GT-100 Version 2.0 patches, available for free at
  • Version 2.0 software available as a free download for all GT-100 owners