I will write this little article to help the bass players and our guitar brothers use the BOSS GT-6B (and GT-6 in case of guitarists) in a simple but effective way. I will not teach you how to achieve the perfect tone as this is something suggestive - in fact as you will later see, the perfect tone is achieved from your playing technique, the amplifier/cabinet and your instrument and is something which grows with you!
I bet that nine out of ten people who got this pedal were lost in its complexity and flexibility. The only way to simplify the approach is to treat the BOSS GT-6B as a modular multi-effects pedal i.e. do not look at it as one big complex device, but rather as multiple smaller pedals chained together. Because of this, I will refer to the individual effects as 'pedals' as if we are operating virtual individual pedals. It is also important to realize that there are some of these 'pedals' which you'll never use, or you'll rarely use - fine! Even the geekest of all bassists and guitarists never dream to chain all of the existing pedals in their rig. Before I recommend you which are the most common 'pedals' to use and which are not, let's analyze what's the first step every BOSS GT-6B user should do.
When you connect your instrument to the pedal and to the amp, the first thing you will notice is that your sound has an effect applied to it, some bad EQ, and a different volume (either very high or very low) to the one you used to have without the pedal. This will make the chosen effect impractical to use. So the first step must be to assign a patch with a clean tone. With a clean tone I mean as if you are bypassing completely the pedal - so no effects, no simulations, no EQ, no volume boost or cuts. Unfortunately BOSS GT-6B doesn't come with that kind of patch - instead they force you to press the BYPASS button to achieve this effect. But I think that this is a bad thing since you need a clean patch to start from. So how do you get the clean bypassed tone as if you are playing without the pedal at all? Follow these steps:
1) Remove all effects - remove the compressor, distortion, reverb, EQ, AMP/SPK simulation.
2) Set the master effects volume to 110
3) Set the master volume from the rear panel to just the beginning of the MAX marking
4) Set the footpedal volume to 100
In this manner the sound is as if you had no pedal attached between your bass and the amplifier. It is important to save this to a patch and always use it as your basic building block. Now let's see what effects can be useful to us or not:
PREAMP: You would normally need to disable this unless you're recording and your bass guitar sucks (i.e. if you plug the bass into the soundcard and the sound sucks, you may need to play around this - use the default presets). I have a Musicman, so I always disable it.
SPEAKER: Same as above.
EQ: If your bass has an onboard EQ I suggest not use the EQ of the pedal at all...Or else use it to do some abrupt minor tweaking for example to change from normal finger playing to slap bass. In my case, since I have an EB Musicman Stingray 3EQ, it is imperative to use the 'ray EQ because it's far much more sophisticated than the pedal one. Even if you don't have an onboard preamp on your bass, make only minor tweaks, or disable it at all.
COMPRESSOR: This is the most important pedal and is a must for every bassist. The sound is compressed and evened out. Don't even try to play without it. I normally choose the 'smooth slap' preset.
DISTORTION/REVERB/CHORUS: Add these according to your tastes.
Remember that the trick to master this pedal is to begin from a clean patch! In a nutshell, once you have the clean patch, you can add and remove subtle effects at your pleasure. If you have a decent instrument and amp, try to avoid using the AMP/SPEAKER simulation. Another important thing to notice is that unless you are a perfect geek or you want a very personalized effect, you can always use the preset 'quick settings'.