Throughout the history of Black Sabbath there are (so far) three guitars that have been, in succession, Tony's main instrument. These were a) the original red Gibson SG; b) the black John Birch SG; and c) the maroon Jay Dee SG. All have had custom made pick-ups, the first two by John Birch and the third by John Diggins (Jay Dee).
In the early days of Sabbath, a recurrent obstacle to Tony's quest for improvements and modifications was the inflexibility of the established manufacturing companies to entertain any form of customer feedback. Examples of this in Tony's case include; increasing the number of frets to 24 to allow a two octave span, electrically shielding the control cavity, the provision of very light strings and experimentation with pick-ups. It was due to these frustrations that Tony linked up with John Birch, the undoubted father of the British custom guitar. John's interests covered guitar electronics as well as guitar construction so most of Tony's concerns were addressed.
A pick-up is basically a magnet with a coil of wire wrapped around it. When a metal string vibrates within the field produced by the magnet, a varying voltage analogous to the sonic vibrations of the string is induced in the wire wrappings. While that sounds nice and simple, the actual characteristics of the sound that is produced are a complex interaction of a whole host of variables affecting the shape and strength of the magnetic field and the nature of the coil of wire. These include the magnet material, its alignment, its position, the number of turns of wire, its thickness, its insulation, its material, its electrical resistance etc. etc. almost ad infinitum.
It is obvious that experimentation is of primary importance regarding pick-up design and this just what John Birch was able to do. Further down the line John Diggins was able to do the same when he produced the pick-ups that went into the Jay Dee SG. The down side to this however, is that due to the hand-made nature of these devices coming out of small workshops, it is sometimes difficult to make exact replicas once a successful pick-up has been made.
This does then lead to a degree of nervousness regarding the well being of these unique pick-ups (and the unique guitars that they sit in!!), and a dread of what to do if the unthinkable were to happen.
While Tony and I were visiting the 1996 Frankfurt Music Fair, we met up with J.T. Riboloff, at the time the resident Gibson R&D genius. J.T. had built a guitar for Tony 4 years previously, a black SG with Floyd Rose vibrato. The quality of this guitar had always impressed Tony (especially as it had been built in 72 hours!!) and although the two had spoken on the phone they hadn't met. An immediate rapport developed, (J.T. is a fine player, and left handed) and the conversation quickly turned to pick-ups. In the course of the visit to the Gibson stand we met Rick Gembar (general manager of the Gibson Custom Shop Division), Jim Goulomb (general manager of the Gibson Strings & Accessories Division) and Scott Johnson (of Strings & Accessories). All were immediately very keen to start forging new links between Tony and Gibson. (Jim and Scott have since both left Gibson).
Very soon after our return to the UK, Scott Johnson made contact to suggest the development of a Gibson Tony Iommi Signature pick-up. This was a first for Gibson, never having made a signature pick-up before. This quickly led to numerous phone calls between J.T. in Nashville, Scott Johnson in Chicago and myself in South Wales. It was decided that the pick-up would be a standard humbucker size to allow retro-fitting and the sound would be based on the bridge pick-up in the Jay Dee SG. This pick-up is not only quite different in size, but it is sealed in epoxy resin as an anti-feedback measure, which also renders it impossible to disassemble without destroying it (see above regarding the worries over one-off experimental devices, John Diggins himself couldn't remember how he had made it!!). This fitted in though with the idea of the project as it was not the intention to directly copy the Jay Dee device, but analyse the aspects of it that Tony liked in order to produce a pick-up that would completely satisfy him and also be practical for mass production.
This meant that J.T. would have to examine the pick-up at his lab in Nashville. To send the guitar or the pick-up over to the US unaccompanied was far too risky an option, so I was lucky enough to be flown, courtesy of Gibson Strings and Accessories, over to Nashville for a few days in June 1996 with the Jay Dee SG. What followed was the most determined electrical detective work I have ever seen! J.T. just lives guitars. With his encyclopaedic knowledge up pick-ups, he started taking measurements, listened and quickly worked out that there were very unusual goings-on within the Jay Dee that gave it the smooth power with a hint of phase cancellation. I have just enough electrical knowledge to understand what J.T. talks about (e.g. “well Mike, the inductance is the motor of the pick-up, and the resistance is its brake”), so to watch and listen to him at work was a great pleasure. Once he had worked out the way to go, which is a radical break from traditional pick-up design, it was a question of experimenting. He worked constantly, pausing only for the occasional cigarette break, to eat or to take me back to the hotel.
He set up the coil winding machines to wind different numbers of turns of different gauges of wire, tried different magnets, milled the pole pieces to different sizes. Coil winders are not like computers, doubling their speed every 3 months, so all this took a lot of time! At the end of the week we had about a half dozen pick-ups to take back to the UK for Tony to try out.
J.T. put together an SG from unfinished parts so that Tony could try the pick-ups out in a Gibson. I got back to the UK, headed up to Birmingham and that was it! The unit was given Tony's full approval. In January 1997, Tony went over to the NAMM show in Anaheim, California for the launch, and the pick-up got its first 'blooding' on the extremely successful Black Sabbath reunion / Ozzfest tour that summer, loaded into another SG that J.T. built. They also feature in the two SGs (one black and one red) that the Gibson Custom Shop built for Tony in late 1997, as prototypes for Tony Iommi special Custom Shop model. These two guitars are still the main live instruments Tony plays. The pick-up is still in production and available in silver, gold or black covers. It has been used in the Custom Shop models, the factory Iommi SG and most recently in the very well received Epiphone Iommi SG.