Well, my Bluesmaster clean is unmodded and it sounds just like Greg (Bold) and I have described them, and just like erwin's description that i reposted. Tweed Fender Bassman /Early Marshall JTM type sounds with a bit of Blackface that can be dialed in with the bright switch on, the mid boost off, the treble up, and the mid control way down, but you really need a strat or a tele to hear those "classic blackface tones" we all think about like SRV and early Hendrix and guys like that, and for me the c-lator and it's extra bright caps helped too, or an eq pedal set "SRV style" to brinng out the jangle. But really, in my opinion it's mainly about the tweed sound, and it can do sweet clean, boosted clean, PAB boosted clean, preamp cranked dirty, master volume cranked dirty, or anywhere in between and sound awesome doing it, as long as you bear in mind that it is bass heavy, and keep it under control. Depending on which guitar i am using i have to move the bass control around quite a bit, but the majority of the controls stay around the same, with some minor tweaking depending on my mood.

That being said, i have never heard one of the FM's in person, but it is a Skyliner stack which is a lil more classic D-Style, and is supposed to have alot more highs and be more chimey, which if you are looking for a bright sound right out of the box may be the one for you.


I'm not all that familiar with the #183 other than it is clone of Dumble #183, it uses a precision power supply, EL34 tubes, and has some other component changes from the standard OTS, I think it's a Skyliner stack if i recall correctly, but again i'm not sure. I know they sound great, that's all Bold or some of the other guys can chime in with more specs.


***edit i should point out that i normally use Weber 1265 Alnico speakers which are on the warmer side and do roll off/disperse the some of the highs due to their design, so i really have to work to get that blackface "sparkle" out of mine. when i had my old eminence legends in there, they had alot more highs in there and the BF sparkle came through, but they are super loud and VERY punchy in the lows, like organ damage causing, so i took em out. if you had some brighter speakers, like say some bright jensens, weber 12A150's, EV12's, or maybe some nice 10 inch type drivers it would prolly be a different story, IMO just FYI***
Gregg

From what I've heard, Nik will get you the Mercs at cost.  Which is a good deal, but you will have to pay for shipping.  They are by far the heaviest part of the amp.