James Iha

in this video, at the timestamp 0:25 Billy Corgan talks about how he and James bought their big muffs together

James began using a Digitech Whammy II in his live setup starting with the touring for MCIS. In an April 1996 interview with "Guitar School" magazine, Billy states "...there is a bunch of Whammy on the record. James uses a Whammy for his solo in Zero."

James also said the following in a December 1995 interview with The Guitar Magazine (TGM) magazine "We tried to be a bit more obtuse, varied, and interesting. Like on XYU I was using a whammy pedal and I kept getting these intermittent breakups-like dang-dan-dan-dan-dang-dan-dan-dan-dang-fllllplplplplplsh! You just step on the pedal and it destroys the sound! It's like a tape machine going haywire or something."

On the photo of James with his Gibson Flying V, EHX Small Stone (Version 2) can be seen taped to one of guitar's horns.

James is seen using a Electro-Harmonix Deluxe Memory Man at 1:52, in this promotional video for "Perfect".

In this photo of James’ rig from 1995 we can see a Cry Baby Wah.

In this photo of James’ rig from 1995 we can see a Boss Auto Wah

In the 2018 rig tour video for the Smashing Pumpkins, James Iha's guitar technician, Dwayne Berto, reveals that three Dunlop expression pedals are used in Iha's setup. At the 0:17 mark, the pedals' size, grip, and logo markings confirm them as the Dunlop DVP3 Volume (X) Pedals. This information is presented by RJM Music Technology Inc on their YouTube channel.