Double Bass Competition for GK 150 MB?

[Chris Fitzgerald]

Just played a GK combo that was a 150 series at a local high school on a recruiting run out. It sounded great and was super easy to dial in just straight out of my bass. It said MBIII on the front. Wondering which model this might have been, whether they ever show up on the used market, and how difficult they are to repair if they crash?

 

[fdeck]

GK has kept up the product info for the MB at their website, though it's discontinued. As I understand it, the "Series III" was a design update that essentially modernized the power supply and power amp circuits but did not go all the way to Class-D. For instance the picture at their website shows a toroidal power transformer, and the manual mentions Class-H design. GK had generally switched to toroids and Class-H for most of their amps at that point, so it was a natural evolution, and I trust they got it right.

In contrast my old MB150E combo, which dates back to around 2000, has neither of those upgrades.

I'd say it's straightforward electronically, though @agedhorse frequently warns us about continued availability of some components. I can even grasp how it works, which I can't say about the Class-H or Class-D designs. The main issue with mine is that the pots have gotten scratchy, and it's twice as heavy as my new rig, though probably not as loud. In terms of servicing it, the main issue may simply be that the mechanical design is complex, meaning it's a chore to get it apart and back together. Mine now stays at home as my practice amp for electric bass.

MB 150S112 Specs — Gallien-Krueger

www.gallien-krueger.com

 

[Greg Clinkingbeard]

GK has kept up the product info for the MB at their website, though it's discontinued. As I understand it, the "Series III" was a design update that essentially modernized the power supply and power amp circuits but did not go all the way to Class-D. For instance the picture at their website shows a toroidal power transformer, and the manual mentions Class-H design. GK had generally switched to toroids and Class-H for most of their amps at that point, so it was a natural evolution, and I trust they got it right.

In contrast my old MB150E combo, which dates back to around 2000, has neither of those upgrades.

I'd say it's straightforward electronically, though @agedhorse frequently warns us about continued availability of some components. I can even grasp how it works, which I can't say about the Class-H or Class-D designs. The main issue with mine is that the pots have gotten scratchy, and it's twice as heavy as my new rig, though probably not as loud. In terms of servicing it, the main issue may simply be that the mechanical design is complex, meaning it's a chore to get it apart and back together. Mine now stays at home as my practice amp for electric bass.

MB 150S112 Specs — Gallien-Krueger

www.gallien-krueger.com

My S version may be older than yours and it works perfectly, although I did replace the driver when I purchased it several years ago. I owned two series iii versions in the past and one was never quite right. The amp is far from the most neutral sounding combos but it never disappoints. Likewise, I don’t gig with it much because it’s getting old and I don’t trust it.

 

[agedhorse]

There is an SMPS version that I have seen, my docs indicate that it was released around 1990-91.

These are mechanically quite complex and tightly packaged.

 

[DJ Bebop]

I think Pontiac Thrasher has the right idea for upright…

 

[Chris Fitzgerald]

I think Pontiac Thrasher has the right idea for upright…

View attachment 7351973

“We’re gonna need a bigger boat.”

 

[fdeck]

There is an SMPS version that I have seen, my docs indicate that it was released around 1990-91.

These are mechanically quite complex and tightly packaged.

I believe the SMPS actually predates the conventional design. It's how they fit the whole thing into the head-only version. But it suffered from severe reliability issues, and the head was discontinued. My combo had conventional, er, analog, er, line frequency power supply. They sent me some schematics at one point, which reflected this revision history.

 

[bass player 53]

I have chimed in on this before. I have several of the versions of the MB. There are slight variations in the voicing controls. I jotted them down once and have included a photo, based on the manuals. Sorry for the slop.
My beef, as I’ve complained about previously is the crackly pots, which has affected most of them. On a jazz upright bass gig, without pa support, I use an Underwood pickup on a Juzek type bass, directly into a
MBE-III, and also use the 12” extension cabinet. This is fine for a classic quartet or quintet.
I leave a spare extension cabinet and MB500 head in the car.
It all sounds pretty good; not on the level of C. McBride or Dave Holland good.

 

[Ric Vice]

The Original MBE was released as a successor to the 200MB (not the MB 200) which I believe had a mini torriodal power supply attached to the underside if the cabinet with 4 bolts that were clearly visible if you looked at the bottom. Many DB players who loved the 200 MB weren’t fond of the
way the new improved version sounded. FDeck did an analysis of the new EQ points once in the long ago here on these threads. GK then released the MBS has a nod to the DB community with an EQ setup closer to the original 200MB’s. Just my take however. The original 200 MB’s were great. The MBS is also pretty great. The MBE’s IMHO not so great with DB.

 

[DJ Bebop]

“We’re gonna need a bigger boat.”

 

[Barcza]

I used MB150 for longtime, 20yrs ago…
I loved so much! Currenty i have TC Electronic BAM200 with Phil Jones C2 cab, I rarely bring my own amp to a gig, but when I bring, I‘m happy with this rig. The cab is unbelievable god for the 4kg weight, and for the size. The head is limited in features, and it’s EQ section is not so sensitive,but the amp has pretty good natural sound,

 

[Paul New]

I have one of the current MB210 ii combos. It’s full class D and GK claims 500W with an 8 ohm extension. Not the lightest thing-the speakers have ceramic magnets. It sounds pretty good with an HPF in line. I think all the GKs have at least a 1 Meg input impedance.

One drawnack is that there’s no effects input that bypasses the GK preamp. Another is that mine has died twice in the five or so years I’ve owned. Both times GK repaired the unit free of charge and I don’t think my problems are typical of these amps.

I think they also build a 1X10 version of the combo.

 

[Ric Vice]

Bob Gallien is a brilliant amplifier designer. The original 200MB and subsequent MBS were beloved by a whole decade of bassists.
He came up with a compact DB/EB amp that was very successful. Unfortunately, the technology and components those amps were built
keeps changing. So he discontinued those little amps in favor of newer ones that used IcE power modules (the MB 200, 500, 800, and Fusion
Apparently, those amps didn’t sell all that well so now all that remains is the little MB 200.

 

[ProbablyTooLoud]

I have one of the current MB210 ii combos. It’s full class D and GK claims 500W with an 8 ohm extension. Not the lightest thing-the speakers have ceramic magnets. It sounds pretty good with an HPF in line. I think all the GKs have at least a 1 Meg input impedance.

One drawnack is that there’s no effects input that bypasses the GK preamp. Another is that mine has died twice in the five or so years I’ve owned. Both times GK repaired the unit free of charge and I don’t think my problems are typical of these amps.

I think they also build a 1X10 version of the combo.

The aux in on those combos bypasses the preamp but you need a 1/4-1/8 in adapter for effects units or other preamps.

 

[basss]

I had one for a long time, although mine was an mb II IIRC. Nice and small, a bit heavy by today's standards, sounds great at lower volumes but sounds compressed as the volume goes up. Bob Gallien posted here a couple times about an update to this combo but it never happened

 

[Paul New]

The aux in on those combos bypasses the preamp but you need a 1/4-1/8 in adapter for effects units or other preamps.

Yes, it does. Thank you.