Powering a Walkabout Stack - Small Pwr Amp Options?

[Colonel Monk]

Hey Yall:

I have a Walkabout Scout 12. I will have soon a Scout 15 on the way!

I'm in love with the tone I get from the Walkabout - I have also the MPulse 600 and I enjoy the headroom/power, but it's not the same tone. Could be the cabs, I'm not really sure...

Anyway, I have long hoped that Mesa would build a companion amp to the Walkabout that would allow you to create a modular Scout Stack with as many cabs as you like.

I see that SWR has done just that with the Amplite. So I find myself wondering how that would work with the walkabout?

Effects out from Walkabout > Amp in SWR > Amp out SWR > Effects In Walkabout? Anyone tried this?

Would the SWR pwr section color my tone at all, or is it just clean power?

How about two Walkabouts? Can one take say the DI from Main Walkabout and run into the input on second Walkabout? MP600 has a slave in but the Walkabout doesn't.

Any thoughts?

CM

PS I know I can try running both cabs off one head at 2 ohms, but I'm not sure I'm comfortable with that - and it's not scalable to more than two cabs.

PSS I'm not interested in stereo power amps in a 19" rack - the form factor is not conducive to being modular unless you want to rack mount the amps.

[RickenBoogie]

You're not alone, but as it is, nothing else quite sounds like a Walkabout. Not even the Mpulse 600, as you've discovered. And, to make matters worse, the tone from the Walkabout is a combination of the pre AND tube driven power section, so using the WA as a pre only will still fail to capture the magic. Check the Walkabout megathread, this is a common discussion there.

[Colonel Monk]

Originally Posted by RickenBoogie

You're not alone, but as it is, nothing else quite sounds like a Walkabout. Not even the Mpulse 600, as you've discovered. And, to make matters worse, the tone from the Walkabout is a combination of the pre AND tube driven power section, so using the WA as a pre only will still fail to capture the magic. Check the Walkabout megathread, this is a common discussion there.

Problem with the Megathreads, is that they are really long and there's alot of drift if your time is limited.

OK, so what about this - if one has two walkabouts, is there a way to slave the second one?

How about DI from Master Amp into the FX return of the Slave? Anyone tried it?

[Chef]

The MP600 doesn't sound very much like the Walkabout to me.
I've had both.

I think you have two options, and maybe only one if you're in love with the Scout cab...then you really only have one options

Option 1) Get you a big ole, high efficiency multi driver cab. More cone area=more volume. I personally love the Henry 8x8 with my walkabout

Option 2) Get a whole second Walkabout Scout. Two cabs, two heads. Get a nice DI of your preference, and split the signal from your bass to both units.

However, if you have the Walkabout Scout 12, and a Scout 15 cab on the way, you're already on to one setup I ran for several years:
Scout 12 stacked on a Scout 15!

Mine were both 4 ohms, which has the Walkabout pumping out 550 watts.
Nice: more power, more cone area=awesome!

My 15 was an older Mesa diesel 115 with an eminence 3015 kappalite in it.

[Colonel Monk]

Hey Chef:

Yeah I hear you on the MP600 - I started with it, loved it, then tried the Walkabout, LOVED IT MORE! I guess I'm thinking though that in terms of power amps, it shouldn't really color the tone that much right? They are both MOSFET power amps, and since the tone comes from the pre-section, any power amp should work right?

So, I have at times been addicted to the power of the MP600, it's alot of headroom. I will definately try the 2 cabs one amp deal - if it's stable wahoo - but having only one amp is a bit committing if you have an issue.

The cost of a used WB is really less than the SWR amplite - type amp anyway.

I have found some threads about slaving walkabouts - great news, that's really what I want to do is be able to do two amps up to 4 cabs - modular is the key.

What they don't say, is if you tap your FX out to pass signal to the slave, does it kill the signal to the master's power section? Or is it a separate preamp out? Some amps disconnect the power section if you tap the FX out - you have to reconnect something to the FX in or you have no signal to the source amp. This is where I'm confused.

Tom Bowlus wrote that he had another post-pre "output" added, but I find myself wondering if that's necessary.

So I'm thinking, if FX out is a separate pre-out, then you take it to the slave WB to FX in, and there you go.

I can't wait to try it out, I have a Halloween gig coming up and my tone is killer right now. With the Scout 15 it's gonna be as FAT as I like.

Thanks,

CM

[bongomania]

Originally Posted by RickenBoogie

to make matters worse, the tone from the Walkabout is a combination of the pre AND tube driven power section, so using the WA as a pre only will still fail to capture the magic.

???? I thought the Walkabout had a FET power amp section, not tube.

[Chef]

yes, the power section is mosfet.

one preamp tube, one tube to drive the mosfets.

[Colonel Monk]

Originally Posted by bongomania

???? I thought the Walkabout had a FET power amp section, not tube.

I noticed that too, but figured RB meant something different...

It is only a MOSFET pwr section - two 12AX7 tubes in the pre-amp.

[vin*tone]

Chef's got it. It has a tube driver in the Power amp section - similar to the Ampeg SVT 3 Pro.

[Colonel Monk]

Originally Posted by Chef

yes, the power section is mosfet.

one preamp tube, one tube to drive the mosfets.

I stand corrected, in terms of *what* the tubes do.

So, I wonder - if only a single tube is in the pre-section, does that mean the second tube is actually part of the power amp stage? Dual Stage?

I suppose that's why it's so warm...

[bongomania]

Ehh... Both tubes are preamp tubes, and both are simple gain stages. One is for the express purpose of raising the level of the signal up to the operating level of the EQ and fx loop. The other is for taking that post-EQ signal and boosting it into the MOSFETs (which are themselves the parts that are intended to mimic the tone of power amp tubes). The one that is boosting into the MOSFETs is not in any way a power tube, or going to sound like a power tube. It is just a post-EQ preamp tube.

RickenBoogie was right about the power section being a key part of the WA tone--I was just thrown off by his mention of the tube part, I mistakenly thought he was saying it was something else (emphasis on tube power rather than emphasis on the tone of the MOSFET power section, which is incidentally boosted by a preamp tube).

[RickenBoogie]

Yes, what I said was tube "driven" power section, because the 2nd tube acts as the driver stage. And even though the WA and MP600 have similar MOSFET power sections, for whatever reason, the Walkabout sounds different, (read: better)- And to the good Col Monk, if you want to run 2, run them together, (parallel), instead of trying to slave one. Slaving them utilizes only one of the power sections- where splitting your bass signal into both will give max power, to 2 cabs each.

[pfschim]

Originally Posted by Chef

yes, the power section is mosfet.

one preamp tube, one tube to drive the mosfets.

one tube to rule them all

I think if you really wanted a 2x Walkabout, you would probably have to go with Chef's option 2 above, 2 Walkabout stacks, a good DI, and then split the signal into both stacks. I think if you went the FX out - FX return route, you would loose the pre/tube driven MOSFET sound of the second stack.

For example, even though the MP600 has a similar tube driven MOSFET design as the WA, if you go FX - out on a WA, to FX return on a MP600, you still don't get a 600w WA sound. Even if you drive Scout or WA cabs. I know, I tried it, and no dice.

what the heck, get 2 WA stacks.

enjoy!

[sunbeast]

If you use the "effects out" jack on a Walkabout, it kills your signal to the power amp, unless you reroute it back in through the " effects in" jack (in other words, it is a series rather than parallel effects loop). I haven't tried using the DI out to drive an "effects in" with my Walkabout, but that might work. You definitely wouldn't want to send the DI signal to the front input jack though (you would be sending your signal through two preamps unnecessarily)! I believe the DI out is post Master, which means that it may actually have "all the Walkabout tone"- so you might try using that to drive the power amp of something else (I could be wrong about that, but the DI signal certainly sounds pretty darn good!).

You could also do as suggested and get some sort of buffered or active signal splitter to send your bass to both amps- I don't have any suggestions as to the best choice here, as there are many available options at very different price points (I've only tried the Radial ToneBone splitter, and also used a Barge VFB-2 as a buffered splitter).

[Colonel Monk]

Hey Y'all

Yeah the two rig thing is a possibility - I've been wanting to do clean / effected rigs anyway - keep the thump and add effects kinda thing... I have a buffered splitter already - nothing fancy just one in and 2 or 3 out (can't remember) with phase switch. So that could easily work. Currently one of the outs is clean with just my clean boost and the other is effected.

But as you know, if you want to use them in stack format you can't reach the knobs - so from that standpoint the slaving would be really convenient.

This is contrary to other opinions in this thread, but I had google searched a few days ago and found this old TB thread from 2004:

can you slave power to a walkabout?

And I quote, from the Walkabout Manual:

The EFFECTS LOOP section of the WalkAbout is responsible for handling the interfacing of external signal processing via its RETURN and SEND jacks located on the Rear Panel.

RETURN: This is the patch point between the pre-amp and power amp for returning a processed signal from your outboard effects back to the WalkAbout. Because this is an input to the power amp, the RETURN jack can be used to access the power amp only. This is handy to use the WalkAbout as a slave power amp or when multiple WalkAbout units are connected for large venue applications.

This is odd, I called Mesa about it before reading that section and talked to their tech support guy - he had no suggestions on how to do this except for buying an MP600 or larger amp, which of course I already have. Couldn't send me a signal diagram or schematic either. This pissed me off - schematic I get but signal diagram? I've never bought a mixer or anything that didn't have a diagram showing you how the signals are routed internally.

If anyone has slaved a walkabout from another walkabout in this manner I would like to know how it was patched.

Also, it doesn't make sense that the slaved walkabout would sound different - if the tube driving the power amp is post fx loop, then the pre-signal from master amp would be inserted in front of the driver tube on the slave amp, correct? And vice-versa. Either way, it makes no sense that the driver tube is bypassed by FX loop.

I've been looking for a schematic but haven't found one yet. Anyone have one? It certainly should help understand the signal path.

I guess I'll call or email them again armed with the quote.

CM

[Crabby]

I take my Walkabout of the Scout cab and run it with a pair of Mesa Powerhouse 8 ohm 115 cabs and the sound is like warm fat thunder! No worries about running at 2 ohms and this rig is so loud and sweet sounding that I have yet to find something better.

[sunbeast]

You are correct about most likely still getting the Walkabout tone if you were able to slave two Walkabouts together (you might be able to use your signal splitter here- Effects out from main WA to splitter, then a line from there to each Effects return)- I think people were only saying that slaving the MP600 or a different power amp would lose part of the WA tone, which suggests that the driver tube is somehow post-effects loop.

I know that I experimented using the preamp from my Mesa Carbine into the Walkabout power section via the effects loop and vice-versa. There was a noticeable difference to me between even the Carbine pre when run into the Walkabout power amp vs. its own power amp. I really liked the Carbine pre/WA power combo alot actually! The Walkabout pre into my old Mesa D-180s power amp was pretty fantastic as well!
Maybe the Mesa Big Block's Power amp is oriented similar to the Walkabout in the signal chain? Though you wouldn't gain much there wattage-wise unless you were running at 2 ohms...

Also- out of curiosity, what buffered splitter do you use? I have considered getting a dedicated one ever since having great experiences with my guitarists Radial, but didn't want to drop that kind of money on one.

[bongomania]

For great quality per dollar, check out www.sfxsound.co.uk --he's a TB'er and he makes an excellent buffered splitter.

[tombowlus]

Originally Posted by Colonel Monk

Tom Bowlus wrote that he had another post-pre "output" added, but I find myself wondering if that's necessary.

As noted, below, if you use the effects loop, you do interrupt the signal to the output section. The "extra" unbalanced output that I had added to mine is parallel, and does not interrupt the signal.

Also, with regard to the tube-driven output stage, no, of course that 12AX7 is not acting as a power tube. However, it is worth noting that the Simul-State technology in the WalkAbout is a tube driver feeding a MOSFET power section, whereas the Trans-Class driver used in the M3/6/9 employs a solid state differential amplifier design that has a faster transient response in comparison to Simul-State. IME/IMHO, you can definitely hear a difference between Mesa's Simul-State and Trans-Class heads, and I would think that at least some of this tonal difference can be attributed to the different driver technologies.

[Chef]

Oh heck yeah.
The Walkabout and M3/6/9 are compleeeeeetely different sounding heads.

That's why I have both