For many the MKI Tone Bender is sort of the Holy Grail of fuzz unobtainability, not only in terms of their scarcity, but in terms of their sound. MK"I" as in number one. The first, the earliest, perhaps the rarest, but by no means the most primitive. For a circuit developed in 1965 the MKI has a thick and "distorted" square wave fuzz sound with some artifacts that can be honed and shaped to produce a very musical fuzz that is both devastating and dynamic.
Unfortunately, we have stopped taking custom orders for our Acid Fuzzer MKI (period correct MKI Tone Bender rebuilds) with the original Mullard OC75/Texas Instruments 2G381 transistor combination. However, we are trickling out a custom run of about 30 of our "Vintage Series" Acid Fuzzer MKI's. These are still built the same way they were in 1965, 100% hand made, all point-to-point on paxolin board, Hunts film caps, carbon comp. resistors, and all that jazz. Each pedal in this last limited edition will get it's own custom painted JUMBO two-piece slanted steel enclosure and come loaded with a trio of new old stock germanium transistors: one black glass Mullard OC75 and two Texas Texas instruments 2G381, 2G381A, or 2G382. We’ll do some swirl finishes and some more tame original style finishes as well. We will still accommodate some basic custom requests such as LED or 9v jack, just let us know before ordering. Additionally, if you want your MKI tuned more for single coils or humbuckers, for more low/mids, etc... we can do basic requests like that as well, just drop us a line with what you want and we'll build it for you.
Please check the "shop" page for availability of these Vintage Series MKI's.
Fortunately, the original 1965 Mullard OC75/Texas Instruments 2G381 transistor set made from unobtainium is not the only set that sounds great in the MKI type circuit. With our Mini MKI the idea is to offer alternate transistor combinations that are sonically very similar to the original transistors and just sound amazing in the MKI circuit. In addition to the standard germanium transistor sets, we also offer the original Mullard black glass OC75 germanium transistors and our Acid Fuzz OC75 germanium transistors. The Acid Fuzz OC75 offers the same sound as the Mullard at a lower price point. If you just want the SOUND of a good MKI in a small pedal board friendly enclosure, this is the way to go.
Proper transistor selection, along with careful tuning, give every one of our Acid Fuzzer MKI’s a very thick, rich, and musical fuzz tone all around. Gated and gritty at low attack settings, smoother, saturated, and sustained at higher attack settings. The “Attack” control of the MKI functions differently than most other fuzzes and is in fact a bias control for the second transistor. Rather than a typical tone bender "attack" or fuzz face "fuzz" style of dirt control delivery where you simply expect the sound to get progressively more saturated and "fuzzy" as you turn clockwise, these have a raspy gated “Satisfaction” Maestro Fuzz-Tone like sound at low attack settings. At higher attack levels they open up to have a singing RAT/MUFF-like smoothness to them, but with an unpredictable note bloom and decay entirely their own. The original design "attack" is a bit of a night and day gated/sustain, with not much in between. We tune our MKI builds to have a much more open and gradual smoother transition that really allows you to fine tune the fuzz to your liking. If you’re not sure what a MKI sounds like, there is an amazing demonstration that says much more than words can here: http://www.youtube.com/watch?v=YJFnV3Eqy_s
One player described the MKI sound generally like this: “I like to visually think of the MKI, as a comet that heats up and then burns out with a long trail of fuzzy cosmic dust at the end”. Yeah it's kinda like that.