Marshall JCM800 2204 vs 2203: Horizontal Input vs Vertical Input

The details:

Tone here is boosted with a Maxon OD9 throughout. For this piece of music it needed more gain than any of the amps can offer. Maybe Ill do another video with no boost but its quite common to do this.

Amps are all recently serviced and biased, but I didnt use the same valves throughout. Same load box and IR though. IR is a blend of sm57 and 421 from my Cali 1999 pack: https://mirrorprofiles.myshopify.com/...

2203 and 2204 circuits have different amounts of negative feedback. 2204 has less, and therefore sounds brighter. This is mostly why the 2203 has the presence higher

Pot tolerances account for why I've set them all slightly different. I could probably match the tones even closer if I spent more time going back and forth on settings. Who really gives a shit when they're close enough?

Vertical input 2204's and Horizontal Input 2204's both have the same amount of filter can caps, but the arrangement is slightly different. The later 2204's also use different spec power transformers which means the voltages in the preamp are higher.

The 2203 is from 1977, the vertical 2204 is from 1979, the horizontal input 2204 is from 1989.