Power Section Questions. Walkabout content.

newbold · #1 04-01-2010, 04:50 PM

Okay folks, I have poked around here, but there are so many threads that have the same words I'm searching for that I would appreciate any phrases or search terms that *you* would search for if you feel my question is overdone.

Since the Power section of the Mesa Walkabout is 6 valve-driven MOSFETs, is there still tube power compression?

The power section saves space and weight but is still all analog...How much does that tube compress the signal for the power stage to ensure it sounds like a tube power amp? Is that the aim of the design?

Which other products share this approach to hybrid design (presuming this is a hybrid design)?

The walkabout is still the amp that's tops on my GAS list, but given the growing number of cigar-box sized amps on the market that can drive a stage with low end only time will tell how unique the walkabout remains.

Are there any real sonic characteristics of different power sections? Different technologies must be used for specific applications from a design perspective: What do I need to look into to understand the difference between Power Section design?

RickenBoogie · #2 04-01-2010, 06:30 PM

The Walkabout is unique, among the horde of hybrid amps available these days. For one thing, one of the 12AX7's is used as the driver for the poweramp. I'm pretty sure this is a key factor in it's tone. And yeah, there are plenty of 500+ watt micro heads on the market, but none of them can touch the sweet tone the WA has, in spades. I'm not alone in thinking Mesa's little Walkabout is the best sounding little amp there is, and the conservative 300 watt power rating is usually plenty enough to drive a large speaker cab in a full blown hard rock band. Not sure if I actually answered your question, but there you go.

joebar · #3 04-01-2010, 06:37 PM

the amp is unique in that it its preamp will break up and overdrive so sweetly without sounding harsh.
it is an honest to god 300 watts if not more and in its combo form- as good as it gets

Taylor Livingston · #4 04-01-2010, 07:09 PM

I don't think you'll notice the difference between 300 watts and 500 watts. Buy what sounds best to you.

The Walkabout sounds awesome to me.

newbold · #5 04-01-2010, 10:43 PM

I'm not worried about power. 300Watts can help a big fat double bass push a 115 and a 210 nicely as per Railroad Earth's Jonny Grubb - I'm talking about the design, and so far it seems unique to me.

It's a 2 ohm stable 300W ultra portable head without digital switching...nobody needs to preach to this choir. I just wonder why it's unique since the design really works.

Anyway, I'm more curious about how much the design of the power section affects this amp's sweetness and the differences between different solid state design, as I seriously doubt that I'll ever (well in this decade at least) be going to a Lead Sled amp.

Walkabout head, 2x BFM Jack10. That's what I'll be moving toward unless something else pops up under my nose.

Anyway, this thread should be less about GAS and more about helping me and other readers find the right resources to educate ourselves

Thanks for sharing!

Taylor Livingston · #6 04-02-2010, 11:36 AM

So I guess your question is: why do all these other mini amps have class D power sections and switching power supplies? First, Class D isn't like digital signal processing where your signal gets sampled in discrete time and voltages, turned into a stream of numbers, then converted back into an analog voltage. I don't think it's fair to malign class D amps as sounding digital or anything like that. The other amps sound different because all kinds of different design choices (mainly in the preamp and EQ IMO), not as much because of the power amp topology.

The other thing to note is that, while the Walkabout is small and light, it is not as small or light as the Little Mark amps, Genz Benz Shuttles, etc. To answer the question I posed at the start of this post, those designs require that topology to be so tiny and light. They aren't bad designs or compromises, they are perfect for what they are.

**DAcat** · #7 04-02-2010, 11:40 AM

That might be a good question to pose to Mesa Boogie Electrical Engineers-they are happy to talk to people with questions...Mesa is making really great sounding amps, and I don't have a cllue how they do it. DAcat

newbold · #8 04-02-2010, 04:43 PM

Not quite, CJ but that's an aspect of it. I love my Digital Switching amp. I play a BBT500 (yamaha) 110 combo. It's more about other Solid State power.

Is there a resource that I can look into that explains in laymans' terms the differences, merits, and shortcomings of these designs?

GK makes great SS gear that's not too heavy.

Really, I was hoping to gain some knowledge while getting people talking, which generally helps me find new things i wouldn't have even thought to look for otherwise.