Train Crash allows you to sculpt your tone with three standard knobs (VOLUME, HI-CUT, GAIN) and additional four switches (CAB, PRESENCE, VOICE, BRITE).
Like in your typical overdrive unit, you control the overall loudness with the VOLUME knob. The HI-CUT pot allows you to cut some high frequencies post-overdrive, which works great for amp tuning. The GAIN control lets you set the desired input gain of the pedal.
Now that we are done with the meat and potatoes, let’s get to the fun part – the switches. You get four of them. The first one is the CAB switch that enables you to choose from flat response, a mild low-end boost (2×12″), or an extended low-end boost (4×12″). Next in the line is the PRESENCE control, which allows you to select one of three options for your post-overdrive high-frequency response – UP for maximum boost, MIDDLE gives a flat response, DOWN provides the darkest sound that pairs up great with bright sounding amps. After that comes the VOICE switch that lets you choose between traditional voicing (T position) and a more modern British type (M position).
Last but not least comes the 3-way BRITE switch, which controls the pre-overdrive high-frequency boost. The UP position is the maximum boost you can get, and it suits humbucker pickups the best. The MIDDLE position turns off this part of the circuit, leaving the response flat. The DOWN position boosts highs just a little bit, making it the best choice in a situation when you want to add only a tiny bit of sparkle to your tone.
Train Crash is your perfect solution if you are already in possession of an amp that you love but would like to easily add a Trainwreck-style overdrive to your arsenal.
Don’t be late; we are departing now!
For further analysis on this circuit, take a look at this thread on Free Stomp Boxes Forum.