Mesa Boogie Walkabout Mega-thread Part 10

[agedhorse]

Your amp took a heck of a fall. With the mounting bolt under tension, this is what can happen.

 

[metron]

That is exactly what happened to my WA. The guy I bought it from basically tossed it in a box with no padding for shipping. The transformer bolt ended up coming a little loose so it was bouncing around in there. I have a bulge on the side next to the transformer as well. Two if the plastic tabs visible on the bottom are cracked or broken off. Finally, I can see through the side that the output board is slightly askew from true meaning those board mounts are also bent.

The good news is that it has worked flawlessly since I got it a few months ago. I was pretty upset about it but if it works, it works.

 

[pfschim]

Well, I am here to somewhat shamefacedly admit that, against advice .. and my own experience, I finally got my Walkabout to choke running it hard at 2.67Ohms last night.

I was doing a first gig with a loud 70's style power trio type band, running the WA into a Bergantino "CN3x12" @ 2.67ohms (8Ohm CN112 + 4Ohm CN212).
I had the gain much higher than usual (unusually seeking the well known WA warm grind) and the Master around 2:00.
I also had a few tunes with a Octave pedal + Envelope Filter .. although I was easing the low end energy off a bit with an fdeck Series 3 HPF.

Played a straight through 100 min set that just cranked from start to finish ... and just at the last 2 songs, the poor WA went into thermal shutdown, killing my stage volume. Interestingly, it stayed on (power light) and the DI kept working (?) .. so I had FOH and other than the band on stage, no one in the audience seemed to know my amp had turned off.

I finished the gig, tore down and went home.
This morning, I worriedly powered the WA up, and it seems to be just fine.

whew.

 

[morebass!]

Well, I am here to somewhat shamefacedly admit that, against advice .. and my own experience, I finally got my Walkabout to choke running it hard at 2.67Ohms last night.

I was doing a first gig with a loud 70's style power trio type band, running the WA into a Bergantino "CN3x12" @ 2.67ohms (8Ohm CN112 + 4Ohm CN212).
I had the gain much higher than usual (unusually seeking the well known WA warm grind) and the Master around 2:00.
I also had a few tunes with a Octave pedal + Envelope Filter .. although I was easing the low end energy off a bit with an fdeck Series 3 HPF.

Played a straight through 100 min set that just cranked from start to finish ... and just at the last 2 songs, the poor WA went into thermal shutdown, killing my stage volume. Interestingly, it stayed on (power light) and the DI kept working (?) .. so I had FOH and other than the band on stage, no one in the audience seemed to know my amp had turned off.

I finished the gig, tore down and went home.
This morning, I worriedly powered the WA up, and it seems to be just fine.

whew.

Sorry to hear this but glad you had FOH to get you through and the WA is okay.
Use the 2x15 next time?

 

[Al Kraft]

Well, I am here to somewhat shamefacedly admit that, against advice .. and my own experience, I finally got my Walkabout to choke running it hard at 2.67Ohms last night.

I was doing a first gig with a loud 70's style power trio type band, running the WA into a Bergantino "CN3x12" @ 2.67ohms (8Ohm CN112 + 4Ohm CN212).
I had the gain much higher than usual (unusually seeking the well known WA warm grind) and the Master around 2:00.
I also had a few tunes with a Octave pedal + Envelope Filter .. although I was easing the low end energy off a bit with an fdeck Series 3 HPF.

Played a straight through 100 min set that just cranked from start to finish ... and just at the last 2 songs, the poor WA went into thermal shutdown, killing my stage volume. Interestingly, it stayed on (power light) and the DI kept working (?) .. so I had FOH and other than the band on stage, no one in the audience seemed to know my amp had turned off.

I finished the gig, tore down and went home.
This morning, I worriedly powered the WA up, and it seems to be just fine.

whew.

It's nice when the engineers provide protection that prevents us from experiencing the potential extreme consequences of our bad judgement/behaviors with their designs!

Really glad to hear your rig fired back up after cool down. My personal recommendation would be to stay in that 4 Ohm range and not subject the components to thermal stress at levels that border on and eventually cause shut-down.

And yeah, I know you already knew that, but someone has to offer the counterargument to that little voice in your head that keeps saying, just one more time won't hurt anything!!

 

[agedhorse]

It takes more thermal headroom than is possible for that circuit to operate reliably at 2 ohms. Maybe if it was cold out, it would be ok.

This is one of the reasons that the basic approach used in the WA that's responsible for the tube amp feel is not directly scalable to much higher power. If it was that easy, I would have done it already

That said, there may be other ways to achieve this but there's a bunch of R&D involved in order for it to get into this territory AND be super-reliable, especially if 2 ohms is to be an option.

Is 2 ohm capability even important to WA users if higher power was available?

 

[rodl2005]

It takes more thermal headroom than is possible for that circuit to operate reliably at 2 ohms. Maybe if it was cold out, it would be ok.

This is one of the reasons that the basic approach used in the WA that's responsible for the tube amp feel is not directly scalable to much higher power. If it was that easy, I would have done it already

That said, there may be other ways to achieve this but there's a bunch of R&D involved in order for it to get into this territory AND be super-reliable, especially if 2 ohms is to be an option.

Is 2 ohm capability even important to WA users if higher power was available?

Wouldn't be for me. YMMV tho of course

 

[pfschim]

Sorry to hear this but glad you had FOH to get you through and the WA is okay.
Use the 2x15 next time?

well, the LDS 2x15 was purpose built to handle my Fender Studio Bass amp (200w all tube) which is somewhat oddly tapped at 8ohms.
So the 2x15 is 8 ohms and that would put the Walkabout at about 165watts of output .... which I have done, but it would not handle this particular band situation (even though there is plenty of FOH on this one).

Its kind of an interesting situation .. have to find the right combo of amp/cab to match the gig .. mostly for sound/tone .. and partly for aesthetics.

The 4Ohm NV610 would probably be the next choice out of what I have on hand right now, but even though its a fairly tall cab, it still tops out just above my waist, and having that CN112 up nearer my ears was really great.

 

[pfschim]

It's nice when the engineers provide protection that prevents us from experiencing the potential extreme consequences of our bad judgement/behaviors with their designs!

Really glad to hear your rig fired back up after cool down. My personal recommendation would be to stay in that 4 Ohm range and not subject the components to thermal stress at levels that border on and eventually cause shut-down.

And yeah, I know you already knew that, but someone has to offer the counterargument to that little voice in your head that keeps saying, just one more time won't hurt anything!!

yeah, even though I have run the WA at 2Ohms many time (sheepish shrug in AgedHorse's direction), I typically do not run it nearly as hard as I did last night.

As a credit to how great the WA sounds though, I did go through several gear combinations that I have at hand, listening for the best combination for the gig.
amps: Walkabout, Demeter VTBP-M-800DJ, Fender Studio Bass, Ampeg PF500 (risky choice), and Ampeg SVT 6Pro
cabs: CN112, CN212, LDS 2x15, NV610

The Walkabout into the "CN3x12" sounded the best of all of them to my ears, for this particular gig (70's rock power trio thing)

 

[pfschim]

It takes more thermal headroom than is possible for that circuit to operate reliably at 2 ohms. Maybe if it was cold out, it would be ok.

This is one of the reasons that the basic approach used in the WA that's responsible for the tube amp feel is not directly scalable to much higher power. If it was that easy, I would have done it already

That said, there may be other ways to achieve this but there's a bunch of R&D involved in order for it to get into this territory AND be super-reliable, especially if 2 ohms is to be an option.

Is 2 ohm capability even important to WA users if higher power was available?

I have a few 8 ohm and 4 ohm cabs that I would like to be able to combine when I want to, for reasons including, but not limited to pure volume (aesthetics, the look of the rig). So, safe 2Ohm (at least 2.67) operation would be something I would keep an eye out for, but it would not be one of the top 3 things I would look for in an amp.

@agedhorse I am interested to know about the situation where the power amp seemed to stop working (thermal overload protection I think), but the DI kept working .. so the signal path from my bass, into the WA preamp and out of the DI was still working .... which saved my bacon last night for sure. I had no idea the WA would do that. Is this common ? When I have had amps choke in the past (which is quite rare in my 45 years of gigging), they were just totally dead. How does this work in the WA ? (if you can say without revealing any trade secret or IP).
It sure was nice that it worked out that way, my hats off (once again) to Mesa Engineering

 

[Red Planet]

I have a few 8 ohm and 4 ohm cabs that I would like to be able to combine when I want to, for reasons including, but not limited to pure volume (aesthetics, the look of the rig). So, safe 2Ohm (at least 2.67) operation would be something I would keep an eye out for, but it would not be one of the top 3 things I would look for in an amp.

@agedhorse I am interested to know about the situation where the power amp seemed to stop working (thermal overload protection I think), but the DI kept working .. so the signal path from my bass, into the WA preamp and out of the DI was still working .... which saved my bacon last night for sure. I had no idea the WA would do that. Is this common ? When I have had amps choke in the past (which is quite rare in my 45 years of gigging), they were just totally dead. How does this work in the WA ? (if you can say without revealing any trade secret or IP).
It sure was nice that it worked out that way, my hats off (once again) to Mesa Engineering

I think it's fairly simple the DI signal must be coming out of the amp just before the solid-state section of the power amp. So the power amp shut down but the signal coming through the preamp was still able to continue on through and only the speaker out was shut off. I'm sure old horsey can tell us more.

 

[agedhorse]

I believe the thermal protection opens the output muting relay.

 

[Al Kraft]

The Walkabout into the "CN3x12" sounded the best of all of them to my ears, for this particular gig (70's rock power trio thing)

I absolutely love the WA into my Berg CN212, so I'd imagine the 3x12 set-up would be eye watering! As I've often said, the WA and Berg CN212 is what my 112 Scout combo wanted to be if it ever grew up! And I agree 100% that the fdeck HPF-Pre Series 3 works brilliantly to get the most out of the WA.

While I like having 2 Ohm capability in a head, it's far from a deal breaker for me if the head doesn't do it. In fact I've always considered the WA a 4 Ohm head for all practical purposes. The WA's only problem for me is a shortage of clean power and/or headroom with cabs that need a little more juice to come to life (e.g.Duke's Hathor and Changeling 12" versions, sealed cabs, etc.), or when I need to feed a lot of drivers in one or two cabs to get the gig volume I need.

If we could get a WA V2 that could deliver say 500 honest Mesa Watts at 4 Ohms, I could live with it also being 500 or even 400 Watts at 2 Ohms. I'm not sure something like that is a realistic option or would even offer a useful engineering solution given the uniqueness of the WA design and power scaling/thermal management challenges. FWIW I pulled 500 Watts out of the air, more would be nice, but 500 seems to be a workable compromise between 300 Watts today and asking for too much and not getting a shot at a WA V2.

My understanding is that the WA is a bit of a unicorn that can only realistically exist in a very narrow power realm while delivering its impressive tone. I suspect that if a V2 more powerful unicorn can be developed, the attributes that we all like so much might dictate a few compromises in terms of things like long term reliable 2 Ohm operation...or at least not allow the typical 2 Ohm equal to or greater than 4 Ohm power output we have come to expect. For me, this would be a fair trade off to get that higher powered WA V2.

 

[Luke the Fluke]

Interesting fact - when I had the mesa authorised repair guy put a new transformer into my walkabout he obviously tested its output to check that whatever blew the transformer hadn't damaged the fets.
I meantioned that some folk on here were getting 500w at a 2ohm load and his response was that it was a good way to break the amp and have to pay him money. He also couldn't see the point as His measured output at 4ohm was a tiny bit under 400w- bonus!

 

[Al Kraft]

Interesting fact - when I had the mesa authorised repair guy put a new transformer into my walkabout he obviously tested its output to check that whatever blew the transformer hadn't damaged the fets.
I meantioned that some folk on here were getting 500w at a 2ohm load and his response was that it was a good way to break the amp and have to pay him money. He also couldn't see the point as His measured output at 4ohm was a tiny bit under 400w- bonus!

That's what I call an honest 300 Watt amp!!

 

[WoodyJ]

For several months I have been looking everywhere I know of to look, to find a well-kept Scout 12 or 15 Extension Cabinet. No luck, the ones that pop up for sale seem to sell faster than immediately.

So, I have come to conclusion that my best option at this time is to get a Subway 1x12 cabinet. My Walkabout 12 combo is 4 ohms so I will need to replace the speaker with an 8 ohm one. Here is the conundrum....

For the Walkabout cab, would you recommend a Mesa Scout 8 ohm replacement speaker, a Subway replacement speaker so that both speakers would match or something else like an Eminence Delta 12 LFA? (44 Hz- 3K Hz)

Thanks, I welcome your opinions!

 

[agedhorse]

Can you confirm that your combo does not have a passive radiator?

I will have to review the data to see if the Subway driver is an acceptable choice, nut the 8 ohm Scout version is what it would have shipped with originally. The Delta 12 LFA is pretty dark, and i don't think it will be a good choice.

 

[WoodyJ]

Can you confirm that your combo does not have a passive radiator?

I will have to review the data to see if the Subway driver is an acceptable choice, nut the 8 ohm Scout version is what it would have shipped with originally. The Delta 12 LFA is pretty dark, and i don't think it will be a good choice.

Thanks for the reply, agedhorse.

Yes, it has the passive radiator on the underside. My Scout is one of the earlier versions with the rhino Tolex and it still has the original 4U (I think) speaker which sounds fine. The amp is silver/black and has the active/passive switch.

 

[lomo]

I absolutely love the WA into my Berg CN212, so I'd imagine the 3x12 set-up would be eye watering!

Yeah-WA>>>3x12 is the shizznit IME/IMHO....although I suppose what this really means is WA>>>enough cone capacity to make it luxo loud is "the trick".

 

[two fingers]

I certainly won't argue with @agedhorse regarding whether or not it is a "good idea". But I have run my Walkabout stack (15" 4 ohm combo and matching 15" 4 ohm Scout cab) ridiculously loud at 2 ohms with no issues. I have not, however, tried it using an octaver. I have no idea if running those lower frequencies super loud would make a difference. I do play 5 strings almost exclusively.

I usually get to "ridiculously loud" with the gain just before breakup and the master volume somewhere between 1 and 2..... as in I turn the master volume knob about 10 degrees and it's thumping.... like, rattle the walls loud. I only ran it that loud for a few outdoor shows and don't recall whether or not it was hot out.