This info. is from a post which I can't find anymore.

Hi! My name is Donal Wool and this is my very first post to 
the list. I've been reading the mailing list for over a year 
now and am so glad that it's back up! If you're a fan of Ty 
like me, than you know what it is to want to have some of that 
incredible tone that Ty got on the first 4 King's X albums; 
especially Gretchen goes to Nebraska! Ty basically used a Fender
Elite Stratocaster and a Gibson Lab Series L5 on the early King's X
records and both are EXTREMELY rare to find as they were only
produced for 2-3 years, each. After my mad quest to find an L5, 
I finally found one after 5 long years!!! Now I'm interested in 
selling my Gibson Lab Series L5 and thought I would give Ty fans 
the chance to get one! I decided to post this so King's X fans
(the people who want to get an L5 and not the "vintage" people) 
could be given "first bids" before anyone else. I'm asking $500 for 
my L5. I think this is a fair price, but I am open to offers or any 
trades. For those of you who don't know, the L5 is a 2-channel solid-state 
combo amp with 2 -12" speakers with a great distortion sound. One 
speaker is an original and the other is a Celestion Classic Lead G12-80.
For those who are interested, please email me at 690547@ican.net and 
be aware that I live in Toronto, CANADA. (In case I have to ship it out to 
someone) Anyways, I hope to hear from some of you! I would also love to
have some email conversations with people who know more about Ty's
equipment/gear.

The electric guitar sound you hear on the first four King's X albums
consist of basically one guitar: The Fender Elite Stratocaster.
These guitars were manufactured by Fender from 1983-1985.
(For more information, check out Fender's, "The Fender Stratocaster" book.
This is the most information I have ever found on these guitars and the
book contains some pictures of the Elite Stratocasters as well.) These
guitars consist of many unique features, the most important being the
active-mid boost pre-amp which boosts the pickups sound by 25db. The
pickups were unique only to the Elite Strats and were not made available
individually. Ty has stated that he mainly used the bridge pickup on the
Elite Strats for his rhythm sound but does use all pickup combinations as
well. (The Elite Stratocasters came with 3 push-button pickup selectors
instead of the standard 5-way switch found on most Strats and this allows
for any pickup combination available.)

> c) how do dummy coils function? Are they connected to some circuit?
>

A dummy coil is just like a pickup except that there's no magnetic
structure.  Since it doesn't have a magnetic field, it can't "hear" the
motion of the ferrous string.  But it will cancel hum just as effectively
as a humbucking pickup if properly wired.  There aren't many instruments
that are like this - the really notable ones are the Alembic Series bass
(that middle coil that is located flush to the face of the instrument
between the regular pickups is a dummy coil), and the old Paul Reed Smith
bass which had a dummy coil in the back as well as three single coils in
the front.  I had an Elite Stratocaster which had a dummy coil under the
pickguard, but I don't know whether the Elite basses had the same deal.