I’m kind of a guitar gadget freak, and I’ve bought many guitar pedals over the years. One of the pedals I like to collect the most are overdrives – Overdrives are guitar pedals that cause the amp to breakup – but in a soft clipping way not hard clipping like a distortion or fuzz – soft clipping sounds more natural and pleasant to the ear, which is why I love talking about Overdrives or ODs.
There are a few different types of OD circuit designs over the years – I’m focusing now on the five I consider to be the most popular and common. 90% of the overdrives on the market today are derived from one of these five types.
Tubescreamer type (TS-type)
Arguably the most famous OD type, the Ibanez/Maxon Tubescreamer overdrive circuit is probably the most duplicated and copied circuit. The TS-type OD has a pronounced mid-range and great for stacking with other more transparent OD types, although due to its pronounced nature, will often become the dominant colored OD if you stack it. The Boss OD-1 and its variants are also very similar to the TS circuit.
The original: Ibanez TS-808, Ibanez TS-9, Maxon OD808, Maxon OD9
Copies/variations: Boss OD-3, Voodoo Lab Sparkle Drive, Seymour Duncan 805, BBE Green Screamer, EHX East River Drive, Ibanez Nu Tube Screamer, Keeley Red Dirt Overdrive, JHS Moonshine, Wampler Clarksdale, Maxon ST9, MXR GT-OD, Maxon TOD9, T-rex Diva Drive, Earthquaker Dunes, Walrus Warhorn, Way Huge Green Rhino
Blues Driver/Full-Range type (BD-type)
The Boss BD-2 Blues Driver circuit is also known as a ‘full range overdrive’ circuit, and is quite different from a TS-type. The BD-type OD can go from cleans to full on distortion or even fuzz territory in some variations. This type of OD is one of the most versatile types you can get. One of the most famous variations of this circuit is the Chandler/BK Butler Tube Driver which is basically a full-range overdrive with a built in 12AX7 preamp tube, adding tube compression. This variation has itself spawned numerous other pedal clones and variations.
The original: Boss BD-2, Boss-BD2W
Copies/Variations: Keeley Super Phat Mod, Fulltone OCD, Chandler/BK Butler Tube Driver, EHX Crayon, Hermida Dover Drive, MXR FET Driver, Walrus Voyager, Seymour Duncan Forza, Maxon VOP9, Maxon TBO9
Although this OD type is technically based on an amp (the Dumble amp), the pedal which popularized this type of OD circuit is the Hermida Zendrive which is a pedal that is essentially a ‘Dumble in a box’ that attempts to give you the warm breakup, touch response, and smooth compression of playing a $100k Dumble amp. Although the Analogman King of Tone and Fulltone Fulldrive came before the Zendrive, I put them in the same bucket of extremely touch responsive tube-like overdrives. The Paul Cochrane Timmy pedal, although not Dumble-based, is a very similar touch-responsive pedal that I would put in the same category. D-type pedals tend to be more transparent then TS-type or BD-type pedals, but not as transparent as K-type pedals.
The original: Lovepedals/Hermida Zendrive
Copies/Variations: Analogman King/Prince of Tone, Wampler Euphoria, MXR Shinjuku Drive, Fulltone Fulldrive 2, Paul Cochrane Timmy, JHS Morning Glory, Earthquaker Westwood
Klon Centaur type (K-type)
Ah yes, the K-type OD. This circuit was made popular by the Klon Centaur which was a pedal hand built by a man named Bill Finnegan. This pedal became very rare and sought after after famous artists like John Mayer and Warren Haynes used it and now it fetches high premiums in the used market. The signature tone of the K-type pedal is that its very transparent. It does not have the mid-range hump like a TS-type nor does it break up into distortion/fuzz territory like the BD-type. This transparent feature makes it ideal for stacking with other ODs.
The original: Klon Centaur, Klon KTR
Copies/Variations: J Rockett Archer, Mythos Mjolnir, Wampler Tumnus/Deluxe, Keeley Oxblood, MXR Sugar Drive, EHX Soul Food
Marshall Plexi/Bluesbreaker type (M-type)
The Marshall-type OD is basically a pedal that tries to emulate a Marshall amp in a box, usually a Bluesbreaker amp or Plexi amp. Just like the D-type, the M-type is essentially a pedal in a box type OD, but is common enough for me to include here. The “original” is the Marshall Bluesbreaker pedal by Marshall themselves, but since then have been numerous copies and variations trying to get a Marshall in a box type sound. These pedals usually have a high amount of gain on tap due to it being based on iconic amps that were pushed to high distortion by the famous bands that used them.
The original: Marshall Bluesbreaker, Marshall Bluesbreaker 2
Copies/Variations: Lovepedals Purple Plexi, Wampler Plexi-Drive, RambleFX Marvel Drive, Keeley El Rey Dorado, Keeley 1962X, JHS Angry Charlie, JHS Charlie Brown, Xotic SL Drive, Catalinbread Dirty Little Secret, Way Huge Supa Lead