Taken from an exerpt from 1992 Guitar Legends featuring SRV:
Like most blues men, Stevie Ray Vaughan was partial to certain instruments and amps. But he wasn't above playing around. The "Number One" axe in Vaughan's life, however, was a well-worn '59 Fender Stratocaster
"It has a 1959 body and 1961 rosewood fingerboard
neck," expained Stevie. "I had to replace the neck because the original fretboard was getting too buzzy. My guitar tech, Rene Martinez, did a wonderful job trying to preserve the original neck, but one day we looked at each other and he said, "Unless we want to do major surgery, we really ought to find another neck." Right around that same time I found a left handed Strat that i really liked. In some ways i think left-handed headstocks work better."
The '59 Strat also is equipped with a left-handed (upside down) vibrato-bar unit, a la Jimi Hendrix and Otis Rush. Stevie strung his guitar with heavy gauge GHS strings (highest to lowest: .013, .015, .019, .028, .038, .058) and replaced the stock frets with bass frets (which are far wider than the stock Strat frets of the 1960's) for improved grip and increased sustain.
Besides Number One (which was destroyed one month before Stevie Ray's death, when a piece of scenery at the Garden State Art Center in New Jersey crashed onto a number of SRV's guitars), Stevie used a slew of Strats including an off-white '61 with a custom pickguard by Martinez, and "Charley," a 1983 custom Strat that Vaughan received as a gift from the late Charley Wirz, of Charley's Guitars in Dallas, Texas. The "Charley" Strat, which can be seen on the cover of Couldn't Stand The Weather, features Danelectro pickups. On the back of the guitar a simple message is engraved on the metal plate where the neck joins the body: "To Stevie From Charley. More in '84."
The unique, hollowed-out yellow 1964 Strat (nicknamed "Lenny"), used on such classic cuts as "Lenny", "Tell Me", and "Honey Bee", was unfortunately stolen. "It was originally owned by someone in Vanilla Fudge," recalled Stevie. "It had four humbuckers in it. Charley Wirz took the humbuckers out and replaced them with a single Strat pickup in the neck position. It would probably be hard to recognize now. That was the first guitar Charley gave to me, and it means alot."
Finally, when the Texas blues man was in a mellow mood, he was known to play a Gibson Johnny Smith model arch-top electric/acoustic jazz guitar. The instrument can be heard on "Stang's Swang"
SRV began his recording career using the combination of Marshall 2X12 combos (for clean sounds) and Fender Vibroverbs/Fender Super Reverbs (for distortion) heard on Texas Flood. By 1984, he found his signature tone in two Fender Vibroverbs and a Howard Dumble 150-watt Steel String Singer.
His signal processing gear was deceptively simple-- an Ibanez Tube Screamer (for volume and gain boost), a Vox wah-wah pedal (or two, as on "Say What") and, occasionally, a Fuzzface and Octavia. The rotating speaker sound (like the Leslie cabinet of a Hammond B-3 organ) on "Cold Shot" was produced by a vintage (late-Sixties) Fender Vibratone Unit.
"I have the Tube Screamer, a wah and the Leslie on my pedal board," explained Vaughan. "The whole system can be activated or deactivated with a simple on/off switch. When I do a song like 'Third Stone From The Sun,' I can't control the feedback with the effects on, so I switch 'em all off and then kick it back when I'm done."