Gk MB 500 or 700RBII for a new cab?

How much of a factor is weight to you?

 

If weight isn't a factor than the 700RBII is hard to beat.

 

This is true. However, the MB500 and it's bigger brother, the MB 800 have headroom as an advantage—allowing one to upgrade cabs when next GAS strikes, LOL!

I am very happy with the MB 800.

 

This is one of those "can't lose" situations. Both are fantastic & sound VERY similar to my ears (with my basses and technique) with the MB being just a tad bit "brighter" IMO.

Both have plenty of power for any venue aside from arenas/stadiums/outdoor shows with proper cabs.
Think you may want to biamp? RB.
Think you want a footswitchable 2nd channel? MB.
Plan to rack it either way? RB
Want to be able to throw it in a little bag and over your shoulder? MB.

 

Good points.

@Sturg — BTW, you can rack the MB 800 with the GK rack ears—but WHY?
The foot switchable feature has never mattered to me, and the second channel is only in the preamp, or at least can be considered so, as the output is one channel only.

The Avatar 126 you have picked is a full range cab. If you are seriously considering Bi-amping, I think you should be able to articulate exactly what (OTHER) cabs you have chosen, why, and what sound you believe you can get that way that can't be had with a full-range cab.

Even for mixing clean and dirty, Bi-amping is of marginal use, IME.
It is a by-gone hack from days of yore, when ALL cabs mostly sucked, IMHO.

Don't get me wrong, it can sometimes (kinda) work fine. Mostly I have just found it annoying and a recipe for endless knob twiddling. YMMV.

 

Hard choice! Just in my opinion of course, if you like it a bit gritty and growly these are easier to get with the RB series. If you like warm but clean the MB gets this easier. They both will do either, just the choices are more native to one or the other, to me anyway. If you play a DB as well as EB the MB series cut its teeth for DB players.

 

Very true. I send my Realist-equipped upright's growl to an MB 800 via a tech21 ParaDI.
Overkill? Yes, but nicely hi-fi out of a fEARful 15/6/1.

 

Best for what specific type(s) of application(s)? Best under which sets of expectations? Best for who?

The point I am making is that once you begin to ask about "best", you are asking a question that is inherently subjective in nature. Therefore the "best" you can hope for is an answer that is also subjective - but not based upon your criteria, but based upon the criteria of another person; someone who may or may not share your particular (unspoken) priorities and preferences. So unless that other person is very thorough about disclosing his criteria (which happens only rarely), so you can determine any similarities for yourself, asking which is "best" is ineffective, at best. In my opinion, of course...

My suggestion would be: get specific. Ask well-defined, explicit questions about features and relative performance of each amp, so that you have the specific information that you need to do the evaluation for yourself - rather than relying upon the judgement of other people concerning what's "best".

MM

 

+1

And you won't hear the 20 Watt difference.