I want to hear any reviews or opinions of it by those who have it.

I dont know. When I emailed nik recently telling him what I was after he suggested the BM with JM mod. I would assume he would just call it the BM if it already incorporated it...maybe not though.

This was Nik's response from our email exchange, "As for the JM mod, it’s pretty subtle honestly. It’s done to make the amp slightly less bright on the clean channel, and reduce aggressive mids (in your face) as well.."

Nah, not all of John Mayer's Dumble's & TR's are not Bluesmaster's (he owns sooo many though it's hard to say.

 His Two Rock Sig is based around the Clean channel of the Custom Reverb Sig. The CRS is based upon the "Classic" style Dumble Clean Voicing with NON-HRm Overdrive.

 A Tone quest article a while back reviewed one of his 100w HRm Dumble Overdrive Special's with EL34's that was used extensively in 07' on Continum.
I attached it below.

He owns many other Dumble accessories and Amps too
1 Dumble Overdrive Preamp (early Prototype)
1 Dumbleator I
1 Dumbleator II
1 Overdrive Special 100w classic (silver chassis,Combo cab with Ev, David Lindly type amp)
1 Overdrive Special 50w non-HRm Skyliner
1 Dumble Modded Bandmaster (used currently to run his Leslie cabs)
1 Dumble Overdrive Reverb (Skyliner, SSS type Verb)
1 Dumble Steel String Singer (100w 4x6L6's, Filter Inductor Section,Silver chassis)

The 100w HRm EL34 ODS can be seen here:


Here is a pic of his many Dumble's:

Dumble 100w NON-HRM Skyliner (Mid 80's, 2 piece chassis)
Dumble 100w HRM Skyliner (Late 80's)
Dumble 100w HRm Skyliner (Mid 90's Script Logo)

Thanks for the infos

Pickmaster are those mods you tried yourself to get close to JM Sound or are those mods which are in a Dumble of JM?

Looks interesting. What speaker do you recommend?

Hm, but Mayer uses 2x G12-65, 2x Celestion Gold and 2x Celestion Century himself?
There's a G12-65Heritage in my 1x12" Combo right now. Maybe the EVM-12L would be a good match in a second 1x12" box Or a Celestion gold 
Or both in a 2x12" 

I have an old 80s EV12L.

Have tried it a number of times in a ported cabinet...similar to pickmasters snakeskin ditto. However, I find it to be pretty useless for OD .....AT LOWER VOLUMES!  :-)
It better at gig volume.

I have tried a eminence kappa Pro in the cabinet and it has a better OD top end but its perhaps a little dark. The best speaker for The ported cabinet is IMO is a Fane 12L ...it has both great clean tone and great OD tones at ANY volume. And the Fane has a massive bottomend similar to a 4x12. Incredible IMHO.