This post will be a comparison of two overdrive pedals: the Maxon OD-808 and the cmatmods Signa Drive. Although I own and have owned several other drive pedals, I thought this would be the most interesting comparison since the cmatmods pedal is essentially a one-to-one clone of the 808, but with an extra switch for different clipping diode options.
The most common context for me to use one of these pedals is in front of an already distorted tube amp as a clean boost. This means using the drive/gain of the pedal at its minimum setting, using the tone knob to cut or boost high and mid frequencies, and the volume to hit the input stage of the amplifier for more perceived gain and better note definition. This application works well for cutting excess low end, accentuating mids, and adding aggression to metal rhythm guitar sounds and was popularized in the 1990’s and 2000’s by bands like Killswitch Engage, Strapping Young Lad, and Unearth, who all used and continue to use the Maxon OD-808.
With the Maxon set up to my normal clean boost settings and the Signa Drive clipping switch set to symmetrical (like the 808) and all knobs set to be identical to the Maxon, the sound is almost identical, but I get a little less low end punch on chugs and less overall coloration to my guitar sound from the Signa Drive. While the difference may be negligible or even unnoticed to most, it’s still apparent enough for me to choose the Maxon for my main rhythm sound despite the extra versatility offered by the cmatmods pedal. However, the Signa Drive may be preferable for a player whose amp already inherently has a lot of low end or similar midrange voicing to what one of these pedals would be adding anyway.
The big difference between these pedals is how they sound when being used for their actual drive/gain characteristics rather than just a clean boost. This application is mostly used by blues, rock, and country artists who want to add a bit of grit to a clean or lightly distorted amp for solos or cutting though a band mix. One major user of the 808 circuit in this way was Stevie Ray Vaughn. With the Signa Drive clipping switch set to symmetrical, the differences between the two pedals are similar to those found while using the pedals as clean boosts. However, with the switch set to asymmetrical clipping, the gain character of the cmatmods pedal becomes brighter, slightly louder, and more aggressive with higher gain settings. With the switch set to diode-free, the midrange accentuation is less prominent and the overall gain range is reduced, but with the most aggressive character.
I would recommend the OD-808 to any metal guitarist to tighten up and aggression to their rhythm sound and the Signa Drive to a guitarist of any genre who wants to add drive to their solo sound and tailor the gain to their exact taste.