the stripe represents various revisions of the Mk III
reprinted without permission-check this out-MESA however was not content to rest on their laurels and after only ~1500 Mark IIC+'s, they introduced the Mark III, the world's first tri-modal amplifier. As with all things MESA, this was a work in evolution that went through five folios or "stripes" until the final product was reached. The Mark III series represents the most extensive line of amplifier evolution and tweaking in the history of Mark amps. The five "stripes" represent the chronology of the evolution of the Mark III. Widely received, the option of three modes was openly accepted but with lofty expectations. When it was first brought out, several people complained that they wanted a bold R2 and the IIC+ lead sound (much debate has surrounded the R2 sound and its relation to R1 but we won't cover that here). The various "stripes" of the Mark III represent the attempts at this request.In reality MESA could have called them the Mark IIIA, IIIB, IIIC, IIID and IIIE.
Like the IIC+ with its famous plus, these stripes were located over the power cord with Mike B.'s initials below. They are merely a swipe with a Jiffy Marker of the appropriate color. The five stripes were as follows:
In order, the stripes were:
None or Black Stripe
Purple Stripe
Red Stripe
Blue Stripe
Green Stripe
As with all things MESA, what these various stages represent are a matter of opinion with respect of the sound character. Don't let anyone pass on a bunch of bullshitee about one being better than the other. They represent snapshots in time of the development of an amplifier line. If the amplifier gets you the tone you want, the jiffy marker is nothing more than a mark of its vintage. Much anxiety is generated in the Mark III group by this extensive evolution, much because of misinformation about what these stripes represent.
#1 - No mark or a little dot. Only a few hundred then some balck marks or "+"'s .
- Lean and powerful amp with more output power than a IIC+
#2 - Purple: reshaping of R2
- R2 was shaped to be more "rounded" and less gain, with improved level
#3 - Red: R2 is like current Mark III
- R2 further developed and very hot. Lead mode is also tweaked to close in on the IIC+ sound
#4 - Blue: Reshaping of R1
- More aggressive preamp gain - reshaping of R1, Power section made akin to IIC+
#5 - Green/Simul-Class: Final R1 and Lead Channel reshaping
- Cleaner