Review: Gallien Krueger MB 150S 112 Combo Amp

Construction: 9.5/10 - takes a lickin' and keeps on tickin'.
Portability: 10/10 - doesn't get any better than this!
Loudness: 7/10 - good for practice, rehearsals & light jazz gigs.
Tone: 9.5/10 - sounds great with every bass I've ever plugged in (at low volume levels).

GK 112This is a popular pro jazz amp for a reason: it's compact, it's rugged and it sounds great! What more could you possibly ask for in a combo amp?

The MBS amp is a pared-down version of the more easy-to-find MBE. It lacks the built-in chorus, the stereo outs and the sweepable mids, but is otherwise essentially the same amp. The XLR output has a ground lift switch, but there's no post-EQ option; it runs directly from the input. (I miss the post-EQ option more in the studio than I do, onstage.)

Next to the input, there's a -10dB pad switch that I always leave on. When switched out, the gain gets a little out of hand. The volume knob should also be used to keep the input signal in line to prevent preamp clipping. You get your stage volume from the "Output Level" knob, later on.

I seldom ever touch the 4 band EQ section. I just use the voicing filters. There's a bass cut switch (useful for killing excess boominess), a "Contour" trimpot that thickens up the tone nicely and a "HI Boost" trimpot that adds a nice touch of treble, without being too noisy. It's helps make up for the lack of a tweeter. Both trimpots sound the best when used in moderation; I don't crank them.

The onboard limiter adds a lot of hiss. Thank goodness it's defeatable. I only use it if I'm worried about power amp clipping at higher volumes.

Some amps sound lousy with passive electric basses, but the GK sounds very good. It particularly likes my P bass. Piezo pickups plugged straight in sound decent, but for maximum fidelity, you'll still need an outboard buffer.

The sound is very robust and useful. The preamp is one of the better-sounding solid state designs I've encountered. Combined with the 12" speaker, it produces a friendly tone that's slightly mid-rangey but very musical and very "present". It's not gourmet, like you'd get with a 3-way speaker and a fancier amp. It's nice and basic and solid and useful. (What Gallien Krueger does best.) I'd love to try miking it in the studio, someday. (When Hell freezes over and the local project studios start miking bass amps.)

There's plenty of volume for practicing, light rehearsals and low-volume gigs. You can squeeze a bit more sound out by adding an 8 ohm extension cabinet. (You can also switch out the built-in speaker and use a single external 4 ohm cab, or even two 8 ohm cabs with the two speaker jacks they provide. Holy extension speaker options, Batman!) Myself, I found the difference to be pretty subtle (150 watts is still not a lot of watts), and lugging an extension speaker kind of spoils the whole fun of using a combo amp. Besides, the built-in speaker sounds just fine, on it's own.

Thanks to the compact electronics and the unique metal cabinet, the portability factor is absolutely out of this world. This is far and away the most compact and lightweight gigworthy amp on the market. It won't take the place of a really big amp, but for those occasions where a small amp is all you need, the GK is truly wonderful.