John used Marshall JCM800 amps extensively during the Mother’s Milk tour, typically paired with a set of Marshall 4×10 speaker cabinets. At this point, it’s unclear whether John primarily used the JCM800 model 2203 (100W) or the model 2204 (50W).
From the available photos, it’s evident that John used several different JCM800 amps, most featuring vertical inputs. On rare occasions, such as during the Pinkpop Festival, he was seen using a JCM800 with horizontal inputs. These later models are generally considered less desirable than those with vertical inputs, due to circuit changes that resulted in a grainier sound.
It’s also worth noting that, at least in 1990, John didn’t rely exclusively on JCM800 amps. While most TV appearances during this period show him using a JCM800 (as seen in their March 1990 performance on Letterman), John also used a Marshall JMP head—such as during the Kawasaki gig in 1990. Additionally, for the few shows the band played in early 1991, John primarily used a Mesa Boogie head before switching back to the JCM800 following the release of Blood Sugar Sex Magik.
Marshall JCM800 Amp on Blood Sugar Sex Magik
Although precise details remain unclear, footage from the band’s recording sessions in the 1991 documentary Funky Monks shows that John used a JCM800 during the recording of Blood Sugar Sex Magik, at least to some extent. John also mentioned in several interviews that he used Marshall amps on the album.
I played through a Marshall bass head and a Marshall guitar head – sometimes only one of them, and sometimes both of them.
Guitar World (USA), November 1991
From John’s statements, it’s evident that he used two main amps during the sessions. However, this raises questions about the purpose of the other amps seen in the footage, especially since one appears to be turned on, as indicated by the light on the on/off switch. These additional amps could have belonged to Flea (though this seems unlikely, as other amps are visible on Flea’s side of the room) or may have been extra Marshalls John experimented with at the time.
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.
Original source needed
It’s plausible that the JCM800 was one of John’s two main amps for the BSSM sessions. In the footage, a cable is visibly plugged directly into the amp, and during the subsequent BSSM tour in 1991, John extensively used a pair of JCM800s on stage. This suggests he favored the amp and likely used the same model both live and in the studio.
Interestingly, the JCM800 seen in the recording sessions has horizontal inputs, a feature often considered inferior to the vertical input models due to changes in the circuit design, which gave the later models a grainier sound.
As for the bass amp, it’s difficult to determine which of the amps shown in the footage was used for bass. However, if you’re interested in some theory-crafting, there’s plenty to speculate on.
Only the 100w 2203 model changed the circuit slightly. The 50watt JCM800 2204 model was excactly the same, vertical or horizontal inputs – no difference in how they sound. Great amps.
I think the “cabinet” on the right is just a roadcase for a cabinet.
You’re probably right – no idea how I missed that.