- Apr 3, 2003
- 35,515
- 19,942
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- Editor-in-Chief, Bass Gear Magazine
I've had a lot of people ask me to compare my GK MB Fusion to my Mesa/Boogie WalkAbout, and I was finally able to do a little comparison and put some thoughts together. I'm sorry that I am not able to do a more detailed comparison at this point in time, but I have a lot on my plate! 
So, here goes...
For the uninitiated, the WalkAbout is a compact, but "conventional" hybrid head, with a tube preamp and a tube driver (Simul-State) for the MOSFET power section. It uses a conventional power supply with a toroidal transformer. It is rated at 300 watts into 4 ohms, and weighs @ 13 lbs. I do have to note that I have an NOS Telefunken (ribbed plate, I believe) in V1 on my Walkabout.
The MB Fusion is what I would call a "micro" head, utilizing class-D topology and a switch-mode power supply (SMPS). It has three preamp tubes, and utilizes all six valve stages (same preamp as seen in the Fusion 550). It is rated at 500 watts into 4 ohms, and weighs @ 4.5 lbs. I am using the stock tubes.
I did most of my comparisons at lower volumes, playing through my Bergantino HT110, though I did try both heads with several bigger cabs when I pushed them a bit harder (though that little HT110 can really take a lot!). To cover a wider range of potential instruments, I switched back and forth between one of my MTD 535's and my Alleva-Coppolo LG4 Classic (in both active and passive mode).
For my first round, I wanted to keep them both fairly clean sounding, so I left the EQ controls on both heads at "noon" (which of course is not necessarily the most "flat" setting for either head), set the Master to noon, and kept the Gain well below noon on each head. Initially, I left the various settings on the Fusion (Presence, Deep, Limiter) off. The overall tone of these two heads is certainly fairly similar (both are warm yet very clear). The WalkAbout sounds bigger and more powerful down low (if you leave the Deep switch off on the Fusion). Engaging the Deep switch brings the GK's B string performance very much in line with that of the Walkabout, but the mids get a tad darker. After playing around with it a bit, I was left with the impression that I will probably use the Deep setting when I play a 5-string through the MB Fusion, but I think I prefer it turned off when playing a 4-string. Compared to the MB Fusion with the Deep on, the lows on the Walkabout were tighter.
Still speaking in terms of a fairly clean signal, the Walkabout has a bit more warmth & wool to the mids, and has a slightly thicker sound, overall. The highs are a bit more "vintage" sounding on the WalkAbout and a bit more "modern" sounding on the MB Fusion. There is a certain brightness and sheen to the GK that isn't there on the Boogie, though it is not a harsh thing at all. The WalkAbout is more full & round, and the GK is more harmonically rich. The MB Fusion does have more headroom (especially in terms of clean headroom), and the Boogie has more note-to-note separation and texture (though with some grit) when you a pushing higher volumes.
Playing these heads with some intentional tube overdrive produced some interesting results. I left the EQ's at noon (though you can definitely move the nature of the overdrive around a lot by tweaking the mids), and had the Gain knob set between 3:00 and wide open, and I cranked the Master up a bit. Starting at 3:00, both heads give up a lot of grit/growl, but aren't into a flat-out overdrive (at least not with an active bass). When you push them harder, the WalkAbout had more clarity and openness, and the GK gets a bit more warm/dark (which is not necessarily a bad thing). Leaving the controls set where they were, but switching to a passive bass, definitely brought out more overdrive from each head. In general, the GK maintained a more full tone as you added in more drive, and you can push it to a more extreme overdrive/fuzz/distortion than the WalkAbout, though at the extreme end of its limits, I found it to be fairly unusable.
On additional factor worth noting is that the fan on the WalkAbout is a good bit louder.
I really like both of these heads, and I've been a WalkAbout fan boy pretty much ever since I joined TalkBass. More recently, I have been won over by pretty much the entire GK line, and the MB Fusion is definitely something special among the current micro head options. I'm a big fan of the MB200 & MB500, too, and folks who don't yearn for the added harmonics, tube sweetness and potential for tube saturation that the MB Fusion has to offer, the MB500 may be just the ticket.
Long story short, I'm not getting rid of either one (though in all honesty, I don't get rid of much! ).
I hope to delve deeper into this comparison further on down the road, but hopefully this helps in the short term.
Tom.
So, here goes...
For the uninitiated, the WalkAbout is a compact, but "conventional" hybrid head, with a tube preamp and a tube driver (Simul-State) for the MOSFET power section. It uses a conventional power supply with a toroidal transformer. It is rated at 300 watts into 4 ohms, and weighs @ 13 lbs. I do have to note that I have an NOS Telefunken (ribbed plate, I believe) in V1 on my Walkabout.
The MB Fusion is what I would call a "micro" head, utilizing class-D topology and a switch-mode power supply (SMPS). It has three preamp tubes, and utilizes all six valve stages (same preamp as seen in the Fusion 550). It is rated at 500 watts into 4 ohms, and weighs @ 4.5 lbs. I am using the stock tubes.
I did most of my comparisons at lower volumes, playing through my Bergantino HT110, though I did try both heads with several bigger cabs when I pushed them a bit harder (though that little HT110 can really take a lot!). To cover a wider range of potential instruments, I switched back and forth between one of my MTD 535's and my Alleva-Coppolo LG4 Classic (in both active and passive mode).
For my first round, I wanted to keep them both fairly clean sounding, so I left the EQ controls on both heads at "noon" (which of course is not necessarily the most "flat" setting for either head), set the Master to noon, and kept the Gain well below noon on each head. Initially, I left the various settings on the Fusion (Presence, Deep, Limiter) off. The overall tone of these two heads is certainly fairly similar (both are warm yet very clear). The WalkAbout sounds bigger and more powerful down low (if you leave the Deep switch off on the Fusion). Engaging the Deep switch brings the GK's B string performance very much in line with that of the Walkabout, but the mids get a tad darker. After playing around with it a bit, I was left with the impression that I will probably use the Deep setting when I play a 5-string through the MB Fusion, but I think I prefer it turned off when playing a 4-string. Compared to the MB Fusion with the Deep on, the lows on the Walkabout were tighter.
Still speaking in terms of a fairly clean signal, the Walkabout has a bit more warmth & wool to the mids, and has a slightly thicker sound, overall. The highs are a bit more "vintage" sounding on the WalkAbout and a bit more "modern" sounding on the MB Fusion. There is a certain brightness and sheen to the GK that isn't there on the Boogie, though it is not a harsh thing at all. The WalkAbout is more full & round, and the GK is more harmonically rich. The MB Fusion does have more headroom (especially in terms of clean headroom), and the Boogie has more note-to-note separation and texture (though with some grit) when you a pushing higher volumes.
Playing these heads with some intentional tube overdrive produced some interesting results. I left the EQ's at noon (though you can definitely move the nature of the overdrive around a lot by tweaking the mids), and had the Gain knob set between 3:00 and wide open, and I cranked the Master up a bit. Starting at 3:00, both heads give up a lot of grit/growl, but aren't into a flat-out overdrive (at least not with an active bass). When you push them harder, the WalkAbout had more clarity and openness, and the GK gets a bit more warm/dark (which is not necessarily a bad thing). Leaving the controls set where they were, but switching to a passive bass, definitely brought out more overdrive from each head. In general, the GK maintained a more full tone as you added in more drive, and you can push it to a more extreme overdrive/fuzz/distortion than the WalkAbout, though at the extreme end of its limits, I found it to be fairly unusable.
On additional factor worth noting is that the fan on the WalkAbout is a good bit louder.
I really like both of these heads, and I've been a WalkAbout fan boy pretty much ever since I joined TalkBass. More recently, I have been won over by pretty much the entire GK line, and the MB Fusion is definitely something special among the current micro head options. I'm a big fan of the MB200 & MB500, too, and folks who don't yearn for the added harmonics, tube sweetness and potential for tube saturation that the MB Fusion has to offer, the MB500 may be just the ticket.
Long story short, I'm not getting rid of either one (though in all honesty, I don't get rid of much!
).I hope to delve deeper into this comparison further on down the road, but hopefully this helps in the short term.
Tom.
Thanks for catching that! Yes, three tubes, using both valve stages in each tube.
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