Any of the OTS circuits will be fine with the 4x12. Remember, Robben Ford used a 4x12 with G12-75's for a while in the 80's and it sounded great. (His amp is a Skyliner NON-HRm BTW, AKA the "Ceriatone Ford Mustang 100w"). Joe Bonamassa also used 4x12 cab's at one point with his Two Rocks, Van Weelden's, and Carol-Ann amps (which are all Dumble clones with different circuits from HRM to NON-HRM, Skyliner, Bluesmaster, ECT.

 If you ever decide to add a Marshall type amp you can split the cab and each amp will have a 2x12.

Although my amp has a Skyliner stack here are my settings with a D-lator:

GE short gray plates in V1 & V2,  Raytheon long Black plate in PI

 Pre Vol:6 (1:00)
 Bright: Off
 Deep: Off
 Mid Boost:ON
 Rock/Jazz: Rock setting
 Treble: 5 (12:00)
 Middle: 4 (11:00)
 Bass: 4 (11:00)
 OD level (Drive): 3 1/2 (10:30)
 OD Volume: 6 (1:00)
 Master: 4 (11:00)
 Presence: 5 1/2 (12:30)

 Dumbleator Send  4 1/2 (11:45)
 Dumbleator Return 5 1/2 (12:30)
 Dumbleator Volume (Overall Master Vol): My preferred setting when @ a gig is around 6 (or 1:00)

 Yes I measured, they're approx.10ft. You have to measure them with a pF meter for them to be accurate although, not just by length.

Both of the cables are 270 pF individualy, not the total of the two.

That's alright, here's how its all set up:

The input from the guitar goes to the preamp

The preamp has an output (Or "Send")

That Output goes to the Input of the D-lator

The Output of the D-lator goes to the Input (Or "Return")Bluesmaster's power amp.

 I'm using RG-400 with 1/4 plugs as regular connection cord from the Preamp+Pwr to the D-lator. Each length of cord is 270pF.

 The concept is quite simple, all I'm doing is substituing one preamp for another. 

When I was using a mixed cab (EvM12-L & a Celestion G1265) I mic'd the Celestion and the Ev was powerful enough that the Sm57 picked up the lower frequencies it produced. I soon changed to just a 2x12 with 65's although.

With different preamp tubes you'll get different results with the gain trimmer.

Yeah its just a standard 4U SKB road rack. I see myself switching to a 10 rack in the future and utilizing a Custom Audio Electronics type remote effects switcher.

The G major II is a versatile unit for D-amps. If you use a c-lator and one of those Suhr Mini-Mix II's you should have steller results. When using the Mini-Mix you'll get the ability to run your effects in parallel and still get the C-lators "natural effect" (in series operation) IMO go with the G-major. I use an M300 and its a great unit.

 Yeah I'm working on a remote preamp switcher for the both of them, waiting for parts from mouser. When I get everything setup I'll make another clip to compare. Right now I'm diggin this configuration because its like having 2 amps in one.



Nah, just look for MIL-DTL-17 spec'd (make sure the conductor is stranded) coaxial cable like this:

http://www.aircraftspruce.com/catalog/elpages/coaxialcableconnectors3.php





Yes they're 270 pF per side (send & return from D-lator)




 Thanks for all your kind words guys.

Took some clips 2day of my Quinn 183 pre with Mill Creek/Ceriatone Bluesmaster PWR amp.

Quinn 183 Preamp
Into a
100w Bluesmaster Pwr amp.
TC M300 in the Loop via D-lator with 270pF RG-400 cables (with Master Bright cap ON)
2x12 Ported D-style Cab with Celestion G1265's

Using a MIJ Fender strat with Burstbuckers.







This one has the FET ON (Warren Haynes/Hendrix inspired me)

 I built A/B/Y with remote midi switching so I can switch on multiple amps with one switch. I'm in the process of refining a transformer isolated remote pre-amp switcher & the midi amp switching all in one. I may get into a preset PCU (like a CAE switcher) If I can figure it all out. Basically all to simplify my rig.

 IMHO having multiple amps @ a gig it's very rewarding when everything is set up right (Volume,high/low & mid's mixed right, which effects are switched on with what amps ,etc.). I used to bring a BF Fender Twin reverb & a 69' 100w plexi Superbass to gigs and after getting into D-style amps its like heaven compared. I don't feel complete with just one amp anymore but am suffice with my 100w BM & a 1x12 @ small gigs.

 Here's simple A/B/Y layout w/ Iso Xfrmer's if you want to roll your own.

http://www.diystompboxes.com/smfforum/index.php?topic=89725.0

I've been Running a Dual amp setup for quite some time for my rig.

 I use:

Bluesmaster Pre

or (Both nonHRM & HRM pre's on a switching system)
 
Quinn 183 Preamp

Into a
100w BM Power Amp

with a 2x12 with Ev's or G65's

 Now I either use a 64' Bandmaster with Dumble mods (Skyliner/classic tonestack
  (In a combo cab with a Celestion) that blends wit the OD or cleans very well with no adjustments (just dimmed )

Or I use a Trainwreck/JTM45 Octal Rocket (w/ 6L6's) dimed with a Fuzz face in front of it in a 2x12 with Celestion. This amp only get turned on when I hit the OD on my HRM. (before this amp I used an OLD heavily modified Traynor Yba-1 with plexi mods)


 IMO I recommend a Marshall like a Plexi 100w, JTM45, Modified Black face Fender Bassman or Wreck. Something Marshall based from the 67',68',69' era' will blend nicely with the OD of the amp you have already.

 The key is to match certain frequencies and adjusting Volume is crucial to the sound you'll get. get a Mrshall that is very Bass/Mids heavy and you'll be happy IMO

You'll be happier with either choice. The Bluesmaster will break up quicker though.

 Sorry what I mean is that a lot of them I've tried have malfunctioned or simply didn't work (even when I bought them from a place that tested them). I had to pick through a bunch to get one that  sounded decent & wasn't microfonic. When I got that good one it sounded great but it isn't worth the hassle. I then switched to the Mullard reissue ECC83's which are consistent and sound great in just about all position's even in the PI. I've been using them ever since.