Very Early Dual Rectifier R0028 is mine!

[Russ]

What if Rev. A was a complete SLO clone? Then when they made some changes and made Rev. B it still wasn't Mesa enough so they further made changes and came up with Rev. C? Once in production they realized it was still too close to the SLO design and so they changed it again to make Rev. D while still holding close to the sound of the SLO that they wanted? But they realized that in order to make their own amp design they would have to further change it and created Rev. F? Then they got some lame idea to put in a parallel loop and so the final revision was made and Rev. G was born?

I am sure that a Rev. A and a Rev. B exist. It wouldn't make sense to start with Rev. C.

 

[bunyok23]

or rev a and b are just initial prototypes. probably 1 or two units only.

this is how design prior production is done anyway.

 

[Boogiebabies]

Revision A or B may have been point to point circuits on a breadboard.
Revision C would have been the first PCB as it was made in Taiwan and I am sure Mesa would not order even prototype PCB's with all of those insane traces, relays and stacks of LDR's. Randall may have gone old school and built the proto boards himself, but that's a hell of a lot of artwork. It's not too improbable though since he still hand draws the RK's.