First off, the "SOLO" is not a "RAT" Pedal, but rather the first of a new generation of effects pedals from ProCo Sound. While "RAT" pedals have been a staple of the guitar industry for decades, Charlie Wicks and his crew set out to create something new and revolutionary. In this quest, the "SOLO" breaks with some of the time honored traditions of their previous pedals. As you can see from the picture, the SOLO has the added the cosmetic element of a colored face plate in contrast to the popular black stompboxes we have come to know from ProCo. This is only the beginning, and it just gets better from here.

Housed in the same super structure, the steel enclosure that has become a trademark of ProCo pedals, the SOLO is built to withstand the most demanding rigors of the road. While it also features the standard "distortion", "filter", and "volume" knobs of the other distortion pedals in their line, all similarities end there. Two of the most notable changes are:

Asymmetrical Clipping: Three switchable selectable levels allow you to adapt your sound from a low wattage vintage tube amp effect, to a modern high wattage, high gain head unit. These settings are marked as "HOT", "MELT", and "BURN". This is equivalent of having three different distortion pedals in one. These are accessed via the three way switchblade on the top of the unit. ProCo also suggests using the lowest setting to lower the overall volume of the pedal without losing any of the distortion.

Scoop : This allows you to select the amount of mid range frequencies that you would like to remove. Used in concert with the tone control, you have an extremely wide and diverse tonal pallet from which to choose. It is much like having the mid range control of a parametric equalizer at your fingertips.

ProCo has also opted to retain analog circuitry over digital. Analog circuits have long been thought of as having greater warmth and a more lively sound than their digital counterparts. Based on my tests, I think this was a very good decision on their part.

The SOLO runs on a 9 volt battery or with the optional AC power adapter (not included). Like all ProCo effects, the battery compartment is easily accessible via a thumbscrew with no tools required.