Air and Water are probably the 2 most similar elements in the Index in their use of ambiance and effects. The difference, as Teppei has pointed out is that Water uses lots of modulation to achieve ambiance, while the Air tone is dripping with delay and reverb.
The tones are for the most part clean, with one wobbly, fuzz-laden exception: the end of Broken Lungs. Since the beginning, I've been thinking that the crazy fuzztone used there is Dustin's Zvex Fuzz Factory and at this point I'm 99% sure. Listening to the recent Myspace Transmissions release, Teppei plays the E and C chord booming fuzz part but it doesn't sound much like the album version. It's simple why... Teppei doesn't use a Fuzz Factory and if you've played a Fuzz Factory you'll know that it's pretty damn near impossible to nail some of the tones with other pedals.
The typical clean tones on the rest of the album are very sparkly and chiming and, as I said, are given an airy ambiance with healthy doses of delay and reverb. As you know from reading the pedalboard articles, each member was using a Line 6 DL-4 pedal for the album (with Eddie and Teppei still using them now) and these seem to be on nearly all the time gently adding to the tone. Lots of reverb was used on the album, but it isn't wise to use in a live situation as it muddies the tone quite a bit due to the room's natural reverb. In live shows, this reverb has been replaced with more prominent delay.
If you are looking for Air tones, I'd recommend a single coil guitar through an amp with nice treble and a bit of sparkle (I'm pretty sure Teppei used an AC30 for most of the EP, while the Bassman is getting use for these songs now). Effects wise, I'll stress again that for Thrice tones from Vheissu onward you must get a delay pedal. While they use digital delay, I think they use mostly analog simulation, and my MXR Carbon Copy works very well in adding the right delay ambience. Like I said, reverb is a bad idea in most live situations, but if you're at home it can help your tone. Lots of amps already have good sounding reverb, but if yours doesn't and you really want a reverb drenched air tone (and delay doesn't do the trick) I'd say go for an EHX Holy Grail pedal.
Earth, in theory is the easiest EP to nail with your own tone since it's mostly acoustic, but there's a warm, at-home feeling from the stripped-down production that is impossible to totally recreate live (maybe you can get close if you play in a bathroom or something, haha). The production on this EP is really cool (including the burying of a microphone in a "coffin" for Child Of Dust, which is maybe the most powerful studio technique I've ever heard. There's a picture of that (from Thrice's blog) below. The electric guitar comes into play only once, during Teppei's leads for Come All You Weary. This tone is pure Vox AC30 and Telecaster twang. In live settings, Teppei plays his Tele and Fender Bassman amp for this (neck pickup), and adds a bit of delay for a spacy feel that helps capture the album's vibe.
For the rest of the album, just grab your acoustic, throw some wood in the campfire and sing the night away!
To wrap things up, here's a quick summary of how to get the great tones from the Alchemy Index:
- Use a single coil equipped guitar!
- A good, clean tube amp would help greatly.
- BUY A DELAY PEDAL!!!
- For fiery JCM800 type distortion, check out the MI Audio Crunch Box.
- A phaser or flanger coupled with delay and a clean amp will get you a great watery tone.
- If you can't get enough of the bomb-like fuzz in Broken Lungs (or just want a killer, versatile fuzz to mess with), grab a ZVEX Fuzz Factory.
- For playing at home, reverb can help with Water and Air's spacy ambience, but it's a big no-no for live playing. Delay is perfect for live use (as well as home use).
- For earth tones, play acoustic guitar and sing around a campfire (preferably during the night and with good friends). Turn the "Kumbaya knob" up to 11! (I stole that last line from Thrice's blog, haha)