I want a monster amp...... which one? That is the question..

Sounds like you want an amp that can get the most volume out of the 15A circuit you're going to plug into?
Then none of those may be able to squeeze out the most.

 

You might want to consider this http://www.americanmusical.com/Item--i-GEZ-STLMAX120
Haven't tried it but it looks very impressive

or I'd consider Sansamp into a poweramp. But since you have the Mesa I'm not sure if it is a step in the right direction

 

starts up the chant "mesa, mesa, mesa, mesa,mesa....you like nearly have the best amp combo already but the v-12 will give you what you crave just do it nothing comes close.....

 

I've owned both the Bass 400+ and Titan V12, and I can honestly say the 400+ was a little louder, and probably a bit better sounding. If you're going with Mesa, keep the 400+. If you want a more old-school tube amp, track down an SVT-VR or a vintage SVT.

EDIT: I just saw you were keeping the 400+ either way In that case, still get the SVT. Two very different sounds to choose from!

 

Glad you are keeping the 400+, my first thought was to go with the G-K 2001RB because you love their sound. However, you will only be getting 360 watts per side at 4 Ohms, and it isn't safe to mono-bridge down to 2 Ohms. I honestly don't think it will be enough juice for 2 big 4 Ohm cabs. The other 3 (or 4 if you included the shuttle) are hybrids and you aren't going to get them to sound like an all tube no matter how hard you try. The DB750 does 975 Watts @ 2 Ohms, and the GBE is just a weak mans substitute for a tube amp (I know this probably isn't fair, but I think you understand what I mean), I don't understand why mesa says the V12 pumps less at 2 Ohms than 4, this simply does not make any sense to me?!?!? Anyway K-funk says the V12 is not as good as the 400+, since he A/Bed them I would take his word on it. You like tubes and the 400+ doesn't do the SVT tone IMO. My final advice after all things considered, get a vintage SVT (or if you must an SLM era VR), you will have total tonal tube options at your disposal. One last question ... Why do you want a NV215? I understand a NV610 with a NV215, but not 3 10's and 3 15's. Why not get another NV425? It would be like a 610 and a 215 in a cooler package! I hope I gave you some food for thought. Cheers.

 

I love my GBE-1200. Since you plan on keeping the 400+ (good plan IMO) it would provide a nice complimentary sound, as it is a very quick, articulate sounding head without being sterile or cold. My primary band plays drop-tuned 100% of the time and I have no issues cutting with my GBE-1200/NEOX-212T setup even with the cranked up bass that my guitar player insists is necessary to his sound. Mixing the FET and Tube channels with just a hint of breakup through the tube yields a nice rough sound that I really dig.

The icing on the cake is that no company will serve you better than Genz shoudl you need it. Be it a service issue or just something you were wondering about, they will take care of you ASAP.

 

GBE-1200 is a SILLY loud amp.
In a 1800 seat auditorium with the NEOX212 cab, I was asked to TURN DOWN because I wasn't in the PA much at all.
Even with other cabs, the GBE1200 just wails away and sounds REAL good doing it.

But your keeping the Mesa 400+....that thing should be loud as hell! I would maybe look into some othe cabs. Maybe a SVT 810, a pair GenzBenz Uber 410's, hell, almost any pair of 410's!!!!
And if you're still not happy, get an SVT-CL.

But if it's crazy volume you crave, I'd start by grabbing some more speakers first.

 

Since you are keeping your Mesa, which sounds like a great head for the tone you are going for, you might want to consider the Carvin B1500. It's smaller and lighter than most lead sled amps, has the best spec's per price in the business as far as I can tell (check out the testing and review in the new Bass Gear Magazine... it actually does put out over 1000 watts into 4ohms), very high quality, and it won't break the bank (I believe they are under $700 new).

They are more on the clean side, but the drive control can warm them up quite a bit, and it would give you a really different flavor, be loud as heck, and serve as a great backup to you 400. IMO!

 

+1 A Big Amen to that!!!! I've had SVT's, a Mesa D180, an old Cerwin Vega monster in the 70's......but the B1500 is an absolute killer! Especially for the weight & price factor, you can't go wrong.

 

The cool thing about Carvin is that 10 day 'no questions asked' return policy. You would only be out the shipping if you don't dig it. If the description of the tone seems interesting, it might be worth a try.

Of course, if you want another 'all tube monster', it would be hard to go wrong with an SVT!

 

Carvin B1500

 

How about an Orange stack yourself to match the guitarist's? Would sound great for that type of music.

 

There's also this SWR monster. I don't have one, but looks pretty nice..
www.swrsound.com/products//search.php?partno=4401400000

 

Here's a thread asking the same question:

http://www.talkbass.com/forum/showthread.php?p=6404168

I wound up going with the Mesa V-12 and couldn't be happier.

 

I have not played that big SWR, but have played the SWR750 that it's based on. From what I understand, it's basically two 750's in a huge, heavy single box. IME, the SWR750 is a VERY unimpressive amp, and in no way reaches 'lead sled' performance. Having two of these duds in a stupid huge and heavy box at a very expensive price point does not really appeal to me IMO.

 

Understandable, I had a hard time finding it as well and I'm the OP for that thread!