MB800...can you get a "Boost" sound without a "Boost Knob?"

While I think some extensive R&D went into getting some of the characteristic GK "sound" into the MB series, I don't think they're really voiced similarly to the RB series at all, at least not in my limited experience with the MB series.

I have an unopened MB800 waiting to try out at home, so perhaps some comparisons to my 700RB-II are in order if I get time next week...

 

I was able to get a similar tone to the "boosted" grind on my MB500 on it's "clean channel" by cranking the master volume past 12-3 o'clock and setting volume with the gain, FWIW.

 

If you are trying to get "home" to the GK sound, I would steer clear of the Aguilar. It is in a different universe. Its good marks for tone and power are well-deserved, but that's by people who like the tube amp sound. It has tube growl, but a lot of tube squish, as well. The EQ voicing is far different from the clear punch of the GK.

This won't solve your overall problem, but you might actually want to try the MB200 for fun. You can crank the gain knob and get a nice growl that's a bit warmer than what I've heard from the larger MBs. It really kicks for 200w, and you may be able to get by with it in a lot of situations if you add enough speakers. Decent DI, too.

 

I love my mb800 but it's not quite the same beast as my rb700, it has a rounder bottom end witch gives it a different kind of grunt when you turn up the gain, it's close but not quite in the rb realm.
having them bolth siting together is fueling fantasy of a mb2001rb fusion, 3 tube preamp from the fusion series, biamp capability with horn defeat for the high gain chanel from the 2001, stereo digital power amps....hhaa

 

some people at the effects forum have been working on this lately:

http://www.talkbass.com/threads/gk-rails-in-a-pedal.1122467/

 

In my experience with both the MB500 and the MB800, there is certainly a tonal difference, though it might be somewhat more subtle than what you would experience with an RB series amp head. In my observations, quite a few of the dedicated GK players here, once they transition over from an RB head to an MB head, seemingly expect to find the RB tone and performance more or less directly replicated in an MB package.

If so, that may be an unreasonable expectation. The RB and the MB are of two different power amp typologies, the RB being Class G, while the MB is Class D. So while the two models will have a lot of similarities, each with that characteristic GK punch and clarity, one can assume the similarities only so far.

MM

 

If I remember tonight, I'll double check what I posted and come back.

I've played RB heads for around 12-13 years and just this year picked up an MB500. For the settings I use with my bass, my playing style, etc... they are very similar tonally, with the MB being just a tad brighter and more "present."

 

Checked last night and I had it backwards. Gain cranked and volume set with master on the "clean" channel (MB500) sounds about the same to me as the boosted, dirty second channel.

 

Yes. This is as close as you're going to get to the boosted RB series sound.

Turn the master volume off and crank the gain (maybe to 2 or 3 o'clock to start). Then, very slowly turn the master volume up to taste.

 

The MB and RB series sound pretty different, to me.
The MB have extended lows and highs, and "don't hit the rails" and do the RB series "boost" thing.
You can get some grit out of them; but, it's not the same thing. So, if the RB thing is your thing, you may be happier with one of those.

Also, though the MBF series do have three tubes in their preamp section, I really would call them very tube amp feeling, at all. At least, not in the sense of "big tube amp being pushed hard," where they get a ton more harmonic content, grit, grind, and compression/sag.
Probably better to think of the MBF heads as "a slightly rounded off MB series."

IMO, YMMV, etc.

 

Yep. Just trying to experiment and help you out if I can.