John Frusciante

The Boss SD-1 can be seen beside his turbo distortion from this photos of their performance of "these are the ways" on the Jimmy Kimmel show April 1st

Akkording to John Frusciante Effects he used a TS9 at a show on April 14th 1989 at Shafer Court (Virginia Commonwealth University). The pictures are a little blurry but as the TS9 has a pretty unique look it seems to be pretty certain.

Used on The Empyrean, particularly on the solo for "Enough of Me", as stated in this April 2009 Vintage Guitar interview.

The main stuff for guitar sounds was that rig, and I was treating it with a modular synthesizer. So the recordings usually had nothing more than a wah pedal, distortion, and fuzz. I use the Boss Turbo Distortion pretty regularly, and an Electro-Harmonix English Muff’n tube fuzz, which has really extreme EQ and a big, thick, meaty sound. I used it on the solo for “Enough Of Me.” I turn the EQ up, but leave my guitar Tone knobs down and use either the middle or neck pickup so the initial source sound is really dark and kind of plain. If you blast the tone controls on the effect, you get a really thick, beautiful sound that reminds me of an exaggerated Eric Clapton tone in Cream, where you have this really smooth fuzz. For that solo, I was jumping from low to high notes rather than following a linear train of thought. I was kind of thinking in two ways at once by alternately playing very low notes with high notes, where the octave was displaced by a couple of octaves, and it worked really well.