Guitar Dreamer: Easy Behringer UM-300 mods!

The Behringer UM-300 is a very affordable distortion pedal and it's actually a copy of the famous "metal pedal" Boss MT-2 "metal zone". In its stock form, it sounds pretty close to the original:

https://youtu.be/WK1CTRhdfqg

https://youtu.be/6y8sxE01Uys

The metal zone pedal is famous for its high gain sounds but it usually sounds like a wah wah pedal is connected just before it, as it has this "nasal" mids sound to it.

It's like having a wah pedal connected between your guitar and the MT-2 and the it sounds like to pedal is set to a certain "middle of the way" position. Sometimes, turning down the tone control of your guitar makes little to no difference when using the metal zone pedal. This means that the pedal has a built-in pre-filter (before the clipping stage) and that's actually true. This is what provides this pedal with its specific voicing. This is a love or hate feature of the boss MT-2 and therefore the Um-300 as well.

Let's now get to the easiest mod ever:

If you check the schematic of the Um-300, you will notice the following components on the 1st stages of its circuit:

Removing C18 (10nF) will eliminate one part of the pre-distortion "gyrator" filter. This will make the pedal more sensitive to the treble and the tone control settings of your guitar. Since C18 is a surface-mount component, you can easily remove it by heating up both solder joints of the capacitor almost at the same time. C18 can then be lifted from the board. This small capacitor will most likely stick to your soldering iron if you heat up both solder joints.

You could also clip the solder joints of the capacitors with a pair of diagonal pliers but this could damage the component and the pcb as well.

I would suggest to keep this small capacitor in case you wish to revert the pedal back to its stock form but such tiny components are very affordable if you happen to damage them or loose them. Likely the whole UM-300 pedal is very affordable in case you wish to experiment even further.

Further easy mods:

If you liked the result of the first stage of the easy UM-300 mods, I would suggest to proceed further and remove even more components. The C19 and C20 capacitors also contribute to the gyrator type filter that produces the characteristic "nasal mids" and scooped EQ tones of the UM-300 pedal.

Removing these 2 capacitors the same way -by heating up both solder joints - will result in a more "open" type distortion and a way more versatile EQ controls section. No more weird and scooped middle frequencies!