To understand what Frampton et al are doing in this song, we need to see a live video. The first effect PF uses to get that sustaining synth sound is that gadget that looks like a small stapler. No ma, that’s no stapler – it’s an EBow – short for Energy Bow or Electric Bow. The EBow can create a variety of sounds from a small hand held, battery powered magnetic devise that interacts with the strings and pickups of an electric guitar.The EBow has been around since the 1970s. The latest model is called the Plus EBow (no joke) "plus-e-bow effect" (this is the joke).
The second effect almost mimics a voice, a talk box effect, or wah-wah pedal - it sounds like the effect Frampton used on "Show Me the Way," which by the way was a talk box. The live video shows that it is neither a talk box nor a wah-wah pedal. This particular effect is known by a couple of different names: an envelope filter or auto-wah.
Both terms refer to similar devices that accomplish the same thing - which is to basically provide an automated wah effect – that’s the short, non-technical explanation. It can be used (when the speed is adjusted) to create that wah-wah effect so commonly found on 70s soul and funk records - without wearing out your ankle in process. I used to have a wah-wah, but broke the dang thing using it in bands in the 80s.
On the rhythm guitar, the third effect may be a Leslie rotating speaker cabinet. Well, actually the cabinet doesn't rotate, but the speaker does. This is class effect found on many Hammond organ tracks and George Harrison slide guitar parts. Soundgarden used a Leslie on their recording; however, a good chorus effect should be sufficient to sound like a Leslie and may be what is used here. A chorus, which can be held in your hand, is a lot smaller than a Leslie cabinet and less prone to electronic or mechanical failure - and much cheaper to replace.
Besides using distortion and other standard guitar effects, Frampton utilizes his time honored effect – the infamous talk box to round out this instrumental recording.
Soundgarden’s Very Bizarre Original Video
From what I understand, the concept behind this video was solely the producer's; the band had little input into its direction – although it is reported that they were pleased with the final project. It is pretty interesting in a disturbing sort of way.