Guys-

I've been thinking of up-grading my OTS to the 100w version soon- I just need more headroom & volume (hard to believe - but my bass player & drummer aren't the most subtle of musicians to say the least! .  Can anyone offer a brief overview of the differences between the 100w HRM / Special & Bluesmaster types?  I've been reading posts regularly & I realize tone is VERY subjective - but any opinions would REALLY help before I pull the trigger with Nik.  I really like my 50w special I have- I've modded it slightly - and they were easy mods too- mostly by changing the snubber caps on the OD channel.  The Bluesmaster looks cool as many of the mods are already done, including moving the OD trim to the rear panel- I'm leaning towards more of a 'Marshall' tone than anything.  Is this the one to go for?

any advice would be cool!

Cheers! Mitch.

Mitch,
What mods did you do the snubber caps on your ots, and were you pleased with the results?  I assume it was to tame the highs a bit.
Thanks

Ok here's some copy paste and edit from a other dclone builder:

Non Hrm classiq EQ is the oldest style of dumble amp. A bit more rooted in the
raw fenderish tone. This is the amp that made his reputation. This
would be like early Lindley, Browne, Lowell George, the first
incarnation of his amps.
It can sustain like a mofo! It is a singing OD for sure.
Not much compression, very touch sensitive and dynamic....

Second the Non-HRM Skyliner EQ  low plate is a variation of the above. Dumble modded
several of his older amps with a new tone stack he was developing,
know as the skyline eq because it's output viewed on a scope resembled
a city skyline.
It is a little less Fender but still a somewhat lower gain affair. It
has the same gain as the vintage amp but the new EQ is more "signature dumble" and a little less Fender. Improved cleans from th Vintage model.
It still sustains like a mofo, has a bit better string to string definition and is a little more refined in the tone shaping.

Non-HRM Skyliner EQ  high plate is where he went next, same as above but now the
gain staging is not classic fender. It has more headroom, definition, and punch, more lively and responsive cleans, smoother OD, and a small bit of compression, very touch sensitive, lots of sweet singing tones.

HRM Skyliner EQ   HRM stands for
"Hot Rubber Monkey". This is a second tone stack just for the OD
channel. It is more or less a Marshall style tone stack this allows tone
shaping of the OD independent of the cleans.
A real Dumble of this ilk would be called a Skyline HRM. Smooth as silk, goes from clean to mean like no ones biz. Transition
between is amazing. You can pick clean, a bit dirty, grinding, soaring, all
with your hand and all smoothly with definition. No rasp or buzz. Very refined. Gorgeous smooth tones. A little more compression that the above amps but not in a bad way. Very natural. The dynamic response is second to none. This amps feels like it breathes with you after awhile.
Smooth singing overdrive, completely dynamic, never any rasp or buzz, no IM distortion or other uglies.

Blues Master. Think raw early Fender/Marshall
tone on steroids. The tone stack is decidedly bassman territory,
however because of Dumbles many other difference it is far better IMO.
The cleans here are the best cleans I think I have ever heard, dumble
or otherwise. The cleans will sing and sustain!!! The OD is much less smooth and much less compressed than the above amps. It has some early Marshall vibe to it. Boosted cleans with this amp are to die for. The OD is a bit more raw and edgy then some of the other offerings but with boosted cleans you get the smooth side of things and with the OD you have a less polite and refined tone.
Somewhat like the first Dumbles, though different. Lots of punch, sustain and singing but not as smooth as some of the other offerings. This one can be thick and dense too. Not dark and crappy, just "meaty"...
Open clean cleans to mean and a little rude.
Big fat sick blues machine. Lots of character or soul. This amp will try and steal you girl.Like a tuxedo on a cowboy?.... It can play nice but it can still stomp in the dirt.
last is the same as above with the HRM OD tone stack which gives a little more tone shaping and refining in the OD section.

FWIW Non_Hrm Skyliner EQ High plater is basically the OTS

Overtone Special (2x&L6) Skyliner nonHRM
Overtone Special 100 (4x6L6)  Skyliner nonHRM
Very smooth and warm sounding OD, lots of OD on tap but not as much as S&M, mid heavy cleans (in a good way). Amp that likes to sustain and compress. Easy amp to play... All knobs at noon and you have a sound to work with.

Overtone S&M Special Skyliner nonHRM
Overall brighter amp compared to standard OTS... clean tone is more or less the same (just a tad brighter), on the other hand OD is brighter, more aggressive sounding. Like OTS this amp likes to sustains. In my experience this amp is not designed to switch from clean to OD on the fly. You have to set the clean and stick with it... than go to OD, set the tone again and play that for a while.

Overtone Skyliner HRM
Overtone Skyliner HRM 100
Clean tone is practically the same as OTS or S&M. With additional tonestack at the OD stage this amp offers more flexibility, along with other switchable options (like deep or pull bright on the OD), this amp offers the most tone selections compared to other amps Ceriatone offers. Overall this amp has less OD on tap compared to nonHRM amps, it will not sustain as much as nonHRM and it somehow makes you work for the tone. That's my feeling about this amp.

Overtone HRM Bluesmaster
Overtone HRM Bluesmaster 100 
This amp is completely different. It has different cleans compared to amps above... cleans are more mid scooped, more fendery if you wish but with a lot of low end. This amp possesses a punch like no other amp. Again not as much OD as nonHRM, this amp makes you work for the tone too (very dynamic).

I played all of them... well all of 50W versions. I didn't play the 100W amps, which should give you even bigger tone.
Each amp is special and you can't really go wrong, if you're into D tone. I have met people buying these amps and later on discovered this amp is not really what they were after... but that's what it is all about - finding your tone isn't it.
 

All what was said above is based on my own experience and it might differ from what other will say. Tone is a subjective thing after all isn't it.

By my experiance I would say that's normal...

What I wanted to say is that preamps are very much a like... the power amp will obviously change things, specially if we compare 50W to a 100W amp.

I play a big fat esquire a lot of the time, and the BM is great when you push the clean side to the edge with a nice clean boost or modify the PAB to the original value or both It's probably just what you're after

Gregg