Hi Chris:

THANKS for the great preliminary review. VERY helpful. I'm pretty sure you'll notice quite a difference when you try the amp with the Celestion G12-65's. The Emi RWB's are an OK speaker, but the G12-65's really bring something special to the mix. I'm currently building a 2 x 12 cabinet out of finger jointed pine to house my G12-65's and that will be my main cabinet with the Overtone. I will also, (obviously) build a matching head cabinet for the chassis when it arrives.
I have owned 2 Two-Rock's (Opal and a Custom) as well as a Fuchs, so I'm quite looking forward to putting the Overtone through it's paces when it arrives.
I also have a Rodenberg Flexloop 3D on the way to interface with the passive effects loop in the Overtone and my PCM-70.

You didn't mention any effects in your review. Are you using the loop for any delay or reverb?

I agree with everything said in the review, they're just my thoughts about it.
 Too many usable tones to make a complete review after few days, I'm still experimenting with the controls and waiting for the pedal schematic.
 I agree, and this is the most important part I guess, that it can be sparkle but very warm, scooped and deep like no other amp I've ever tried, you can get best of tone worlds, and above all it has the Marshall grind and it's so difficult to get the famous Dumble chewy tone.
 I have the same difficult in getting Ford / Carlton type of sounds, I guess the HRM version are much more suitable to compress it and get that sound, while this one is a rock machine with a wider palette of tones, I can say it's impossible to have the standard Dumble tone everyone raves about.
 Listen to the video samples on steelbender web site, the Overtone is in that territory.
 It sounds better with humbucker, I've played it with my PRS CE-22 with Lollar Imperials, and with friends' 62 reissue strat with German made PUs, Framus Panthera with Duncan Alnico II pro and custom 5 and with an '80 strat with Floyd Rose.

 Cleans are gorgeous, something to die for and with that volume on pre section you can reach so different clean territories that just experimenting with the first channel needs weeks of tests, you can have all the clean stuff you could ever need, brigth or warm, boomy or thin, maybe it doesn't have the overtones you could expect, but is wonderful, I've never played such a beautiful clean, never.  Some days ago there was in the gig room a friend of mine who plays jazz, after small tweaks to controls he got a wonderful tone for his style of music, and with a PRS! 
It can be very clean at loud volume or have a grind suitable to be a single channel amp to do everything with pedals.  Ah, it works wonderfully with pedals, I've tried Fulldrive 2, Fat Boost, BSIAB2 (all diy) and Mi Audio Crunch Box, and then some ambient effects, from Deluxe Memory Man to Marshall Echohead and modded Boss TR-2 tremolo.
 The volume on pre section makes me think about it as a rack stack, it isn't a general gain control, it's much more like a volume on a pre amplifier going to a power amp.  The amp isn't very loud (anyway I'm using a wonderful 1x12" built by me with birch plywood cloning the Two Rock 1x12 dimension, with a Classic Lead clone by Warehouse Guitar Speaker), and it's possible to play it at bedroom level with good tones.

 As for second channel I'm thinking to it as the perfect plexi, a much more refined Marshall grind, with not so much gain, but round bass response, never farting and highs that are never ice pickin' or fuzzy (to tell the truth if you keep all the volume controls all way up basses are farting, but hey man, you'll never need to rise up the controls and remember I'm playing with a 1x12"), with an harmonic content that it's so rich that you will cut through the band even with scooped mids. I've loved to keep the level down and ratio up, quite a super crunchy sound to be clean with guitar volume control and to get more distorted with pedals  It's perfect!!!
 The ratio control is something totally new to me, this is why I'm still experimenting.
 The distorted channel so have the pre volume, obviously the EQ section with added switches, the Level control which acts like a gain control this time, the ratio and the master volume plus presence.
 The ratio makes the sound bigger and fatter with more open gain, it's strage, I cant describe it better now.

 Finally, I'm happy with this amp like I've never been with any other amp and it suits my needs much, much, much better than an amp focused on Ford / Carlton tone.
 It's chunky, fat, huge sounding, and above all smooth, even if the sound is so directly punching in your face you can hear a so elegance and pleasant sound that it's a joy just to play open chords.  I love the facts that it doesn't have the smoothness and chewiness of famous Dumble players, it's smooth in a much richer and rocky way.

 There are only two issues with it, the first one is a mistake by me, I  should have ordered it with EL34 in place of 6L6GC (Nik is getting better and better, JJ for power tubes and above all Tung Sols for pre), but this is only me, and inspite it has a lot of dynamic I'm still regretting about selling the 1986 I bought from Nik last year.  That amp was the more dynamic I've ever played, it was possible to have gorgeous clean and hard rock / stoner distortion just with guitar volume pot.  My guitar has the '60 wiring and RS Guitarworks Hovland cap to control the Imperials.

 It's definitely a keeper, it will be the only amp I'll never sell.
 

Great post Whitewave.

The speaker plays such a big part in the stereotypical dumble tone.  Don't discount the effect a suitable speaker can impart on your tone.

I was hoping that you were gonna say that it sounds aweful...lol...that would have made me feel better.  Now I just want it all the more...

Yes I checked those right away and man, if Overtone sounds like this I JUST HAVE TO HAVE ONE.


Nik stop kidding around and bring it BACK !!!
 

Marinblues,

Which amp are you refering to when you say "it"?  I haven't listened to any of those clips yet and I'm at work now so I will check them out later today.  Moss has come up with a few variations on the basic D'lite theme so there is going to be some differences in tones.  It may be time to do a little tweaking. 

Right now I'm trying to get a handle on what Nik has put together with this amp.  It's a bit of a "mutt" comprised of several flavors of the various dumbles out there.  I would love to sit down with Nik and rap about this amp.  If you're listening man how about chiming in and giving a few hints as to what you were thinking with this circuit.  Whatever, your reasoning it ended up sounding pretty frickin good.

Hey Marin,

Sure, the Overtone can do any of those tones.  My D'lite can do them too...   The problem is "I" can't do them.....lol.   
What I am finding with the Overtone is with the OD trimmer set to anything past 9 oclock the amp gets a little too bright with the PAB engaged and since the tonestack is lifted there is no way to dial it out.  It makes for great Marshall bite but I'm persistant to getting Larry and Robben Dumble tones.  Time for tweaking.