John Frusciante’s Marshall Bass Head (BSSM)

Based on photographic evidence, and statements made by John, this amp was used extensively on the Blood Sugar Sex Magic album. However, as he never stated specifically which amp he used on the record, we’re left to guess by ourselves.

For most of the basics, I used two Marshalls: a guitar head for edge and a bass head for punch and low end. I split the signal with a DOD stereo chorus pedal. For some overdubs, I used a Fender H.O.T. practice amp, but for a lot of parts, even solos, I just went straight into the board.

In another interview, John states that he uses a 60W bass amp.

I used this little 12W practice amp and that set up got used for most overdubs ’cause it sounded so much better than all the other stuff. For the other meat I got a bunch of Strats, all ’70s models through a Marshall 60w bass head.

Guitar (UK), November 1991

Based on the footage from the 1991 documentary Funky Monks, which followed the band’s making of the BSSM album, John used at least four different Marshall amps.

The BSSM Marshalls

A screenshot from the 1990 documentary ‘Funky Monks’ shows John with four different Marshall amps, plus one sitting on the floor directly behind him.

The two amps that we’re close to one hundred percent positive on the exact models is the one sitting on the speaker cabinet on the right – that’s a JCM800, an amp that John used extensively both during the Mother’s Milk and BSSM tours. The one sitting above it is a Marshall Major 200W – as explained by Dave in the comments.

The amp on the top left is likely a de-branded Marshall JMP 2204, and the one below it could be a late 70s Marshall JMP Super Bass. The weird thing about this last amp is that it appears to be turned on, based on the light coming from the on/off switch, and it appears to have the Marshall badge sitting quite low – very close to the control board, and there’s no visible white line going across the front.


GroundGuitar counts on your criticism and feedback. In case you notice anything wrong with the information posted on this page, or you have knowledge of something that you would like to share, be sure to leave a comment below.

If you notice a piece of gear missing, and you wanna add it yourself, you can do so on this page Add Gear to GroundGuitar.

In case you want to talk to me directly and privately, please use the Contact Form and I will get back to you as soon as possible. (Dan)

Notify of
newest most voted
Inline Feedbacks
View all comments
2 years ago

The amp on top of the JCM 800 is actually a Marshall Major 200W. You can tell because of the taller cabinet on the head-those were custom for the majors to house the larger transformers.

6 days ago

In the Funky Monks docu, we can see several instances where John is using the Fender H.O.T. amp. For example, in the part of the extended cut that shows the entire Mellowship solo, if you look at the left edge of the screen you can see the H.O.T. amp (his was the white version) stacked on top of another small black amp. At the end of the solo he gets up and switches off the H.O.T.

I think that other amp it’s stacked on might be really relevant, though. It can be seen in several places in the video, but the clearest view happens here: at timestamp 1:06:40

The size and shape of that amp narrow it down to a handful of options. In the video, we can just catch the glint of what looks like the usual Fender script emblem on the top left of the speaker grill. There is also distinct white text on the faceplate mid-right, and though we can’t make what it says, we can see the rough size and shape of the text lettering.

Based on all the above, I believe the small black amp stacked below the H.O.T. is a 1990 Fender Sidekick bass combo amp. This is the same year model as the H.O.T. on top, and they changed the lettering font on the bass Sidekick starting that year to a blockier font, which to my eye matches the white text blob we can see in the documentary.

Why does this matter? Well, to my ear, a lot of the guitar parts on BSSM sound like small speakers and cabs due to their tight, boxy, focused sound. Frusciante was known for giving different conflicting stories about the gear he used. I’m very suspicious that the guitar amp and bass amp he was running in stereo with the chorus pedal for a lot of the guitar parts were actually those two combo amps. Even the tone in Under the Bridge, which has a thin chimey trebly amp slightly panned to the right and a focused but slightly overdriven bass tone underneath, more prominent on the left channel, has always sounded like a couple of tiny cabs to me. I’m very suspicious that this pair of amps might be what we hear in Under the Bridge, and many other parts of the album.

We know for sure it’s what we’re hearing in the Mellowship solo because we see it being used in the video there. Using that tone as a baseline and comparing it to the rest of the album, I think it’s used extensively throughout.