Bass Effects Processor


The GT-6B Bass Effects Processor is BOSS' first new bass multi-effects processor in over five years. This fully professional floor-based unit offers new COSM Bass Amp Modeling with new modeled compression, plus other "must-have" effects like COSM overdrive/distortion, COSM wah and reverb/delay. There's also a true analog bypass, plus XLR and digital outputs for recording applications—making the GT-6B the leader in high-quality multi-effects for bass.

Unrivaled Sound Quality

When designing the GT-6B, BOSS’ primary focus was quality—quality you can hear in every component from its 24-bit converters to its true analog bypass, allowing bass players to switch to the pure tone of their bass guitar when desired. A balanced XLR output and coaxial digital output ensure the highest sound quality when recording, giving the GT-6B a decisive advantage over other bass multi-effects.

COSM Modeling for Bass

Thanks to proprietary COSM technology, the GT-6B can model the sound of six classic bass amps including “Concert 810,” “Session,” “Trace,” “Bass 360,” “B Man,” and “Flip Top.” But amps are only half the story, so the GT-6B also includes several speaker cabinet models like 8 x 10, 4 x 10, 2 x 15 and others. Now you can get great tone direct!

Killer Effects with COSM

The GT-6B features BOSS’ finest “bread-and-butter” effects—including chorus, reverb, delay, flanger and more—all tuned for bass guitar. And with COSM Overdrive/Distortion Modeling and Wah Modeling, bass players can get some of their favorite tones and effects without using amps or noisy stompboxes. The GT-6B also features new COSM Compression, which offers models of several well-known compressors. With all of these amazing COSM effects, bassists can literally just plug in and play.

Auto Slap, Looping and More

New performance effects include an Auto Slap feature, which creates automatic slap patterns using Preset or User templates, plus sound-on-sound looping for creating loops “on the fly”—even fat synth bass sounds with killer tracking. There’s nothing else like it!

AD Conversion
24-bit + AF method*
DA Conversion
Sampling Frequency
44.1 kHz
Program Memories
120: 80 (User) + 40 (Preset)
Nominal Input Level
INPUT: -10 dBu
Input Impedance
INPUT: 1M ohms
Nominal Output Level
OUTPUT: -10 dBu (1/4" jack, At OUTPUT LEVEL marking position), OUTPUT: -10 dBu (XLR jack, 600 ohms load)
Output Impedance
OUTPUT: 2 k ohms (1/4" jack), OUTPUT: 600 k ohms (XLR jack, HOT-COLD), 300 k ohms (HOT-GND, COLD-GND)
16 characters, 2 lines (backlit LCD), 2 characters, 7 segment LED
Power Supply
AC 14 V: Supplied AC adaptor (BOSS BRC series)
Current Draw
800 mA
AC Adaptor (BRC series)
Size and Weight ( excl. AC Adaptor )
515 mm
20-5/16 inches
261 mm
10-5/16 inches
75 mm
3 inches
4.7 kg
10 lbs. 6 oz.
* 0 dBu = 0.775 Vrms * AF Method (Adaptive Focus method) This is a proprietary method from Roland that vastly improves the signal-to-noise (S/N) ratio of the A/D and D/A converters.
*The specifications are subject to change without notice.


If you have questions about operating your BOSS product, please check our Knowledge Base for answers to the most common questions.
You can also contact our Product Support department by phone or email.
In addition, we have a library of Owner’s Manuals and Support Documents that you can download and reference.

Owner’s Manuals

Support Documents