Mesa Boogie Mark IIB+ Coliseum - Mike B Modded - Hardwood - Ex-Aerosmith

Up for sale is a very special amp. It began life as a Mark IIB Coliseum. Coliseums have enormous transformers for a 6 6L6 ~180W huge-sounding, no-negative-feedback power section. So starting with a clean that would put most Fenders to shame, with a power section more inline with a steel string singer, together with what would have been back then ample amounts of gain for classic rock. It's roughly this time that it went to Aerosmith. It's unclear what it was used on, but they made sure to label it, and I also have a certificate of ownership.

But a lot has changed in the world of amps since the early 1980s, and so when I received it I had it sent to Mike B, the Mesa amp guru, who did a number of things. The preamp was completely redone to match the last and most gained out of the IIB preamps designs. The "loop mod" was done, which is akin to the "+" mod on a Mark IIC->IIC+. This adds loads more gain and aggressiveness, and also makes the amp and loop just generally more useable. A level control was added to the back to try to tame the volume towards the end of the chain. Finally, all the caps were replaced and Mesa ran out of the old NOS blue caps the day they finished this amp.

This took it way past a typical IIB, into its own unique thing and an absolute beast. I don't have any clips of this one but there's plenty of youtube videos out there of loop-modded IIBs to get the idea. Compared to other Coliseums, it is warmer and less compressed, with more top-end clarity. Just check out an A/B with a IIC+ and see which you prefer!

The amp is wired for 117V. The listed price is without tubes, as I cannot guarantee that tubes will arrive functioning, basically regardless of how well I pack (and I pack very well), and I also cannot verify any claims that tubes arrive not working. Because of this I think it is both parties' best interest to lower the price a little and sell it without tubes. I will ship chassis and headshell in two separate boxes.

So get in touch if you want this one-of-a-kind amp! I'm currently in the process of trimming down my collection of Marks, and I have 3 Coliseum amps currently for sale (the other two a no-stripe and blue-stripe Mark III). I am interested in a few other things which I could do as partial trade:

- Bogner Uber Ultra

- Wizard MTL

- Framus Cobra

- Hiwatt Super-Hi 50

- 5150 III Stealth 100W

- Various late 80s guitars, ESP / Charvel 750XL

More photos will come the next time we get good lighting in the amp area.