Mesa Boogie Walkabout Mega-thread Part 10

[agedhorse]

I think that, no matter what version of a new WA Agedhorse comes up with, we all want more than 300 watts , no ?

This part is pretty clear, the challenge is how, and where it can go while staying as true to the original concept as possible.

The other part is where we might want to go with it given where the industry has evolved. Additional features for example?

 

[agedhorse]

I'm late to join the conversation here but I'm curious as to where the added harmonics are coming from when you turn up the master. Do they come from that driver tube being fed more signal? Or is it just what happens when MOSFETs are fed more signal? Is there a way to design the amp so that you can adjust the harmonic content independent of the volume? Someone mentioned something like that earlier and maybe it was a joke but is this something that could actually be possible? I apologize if that's an ignorant question but I want to say I've seen amps before that had this sort of knob. I realize you can sort of do this by adjusting the gain vs master but the distortion you get from turning up the master on the WA seems to sound different than what happens when you turn up the gain. Am I wrong?

It is a lot more than just a power amp, there are a variety of things happening in the power amp that are responsible, some of them are why it doesn't scale well.

I can't go into specifics as that's proprietary info, but it's along the lines of why an SVT sounds and feels like an SVT and all other variations don't quite sound or feel the same.

 

[kringle77]

This morning I was running the di out to a power amp. By cutting the bass control all the way off, turning master all the way up and then turning up the gain control to taste, I got the best best of tone ever. No low end of course. Love to be able to get that sound in parallel with some clean, lowpassed sound for bottom. That's the od tone that I think people are lusting after. I used the di out knob to control volume to the power amp.

 

[D-Smith]

So, there is still no agreement...

There are those in the camp that want it exactly the same but "at a higher level". But, do you want the distortion of the WA at say the 300 watt level and continue to get dirtier as you get louder OR for it to be 1/2 as dirty ,cleaner) at the 300 watt level and the same amount of dirty at say the 600 watt level?

It seems as though there are 2 preferences here, which is the crux of the difference between the WA and the MPulse 600. There is a specific interaction that doesn't scale in a linear way, so I have to know which way might be preferable to most of you?

There are a lot of options, including taking the WA to an entirely new level, but it has to make sense to a variety of players.

Two power amp sections with a 1/2 power switch like the Prodigy. I'm sure there are many reasons not to do this, but I like the idea.

 

[Al Kraft]

Is there a way to design the amp so that you can adjust the harmonic content independent of the volume?

I've seen frequency analyzer plots from equipment (like a Sans Amp BDDI for example) where a control (the Presence control on the BDDI) is less about gain or EQ than it is about changing harmonic content. I have no idea how this type of circuit scales up to the amplifier world or how flexible/adaptable and controllable it would be on an amp, but since the BDDI in my example is a pre-amp, I'm guessing such a design is possible.

 

[rodl2005]

Don't the WA put out something like 500w @ 2 ohms?
But, yes, I am in agreement, 5 or 600w @ 4 ohm would be handy

 

[agedhorse]

Two power amp sections with a 1/2 power switch like the Prodigy. I'm sure there are many reasons not to do this, but I like the idea.

I have considered using 2 of the 300 watt power amp sections and one way, but you would not be able to get 600 watts into a single 4 ohm cabinet... a deal breaker to some.

The 1/2 power method that the Prodigy uses doesn't apply here. Totally different type of amp.

 

[Al Kraft]

This part is pretty clear, the challenge is how, and where it can go while staying as true to the original concept as possible.

The other part is where we might want to go with it given where the industry has evolved. Additional features for example?

The only extra things I would need other than more power is a variable HPF (and you already have a nice design for that), a mute switch, and having a DI output level control that's independent of the master volume but still let's me have a post EQ DI send that includes the tube pre-amp goodness (maybe not as as easy as the HPF ).

 

[the yeti]

The only extra things I would need other than more power is a variable HPF (and you already have a nice design for that), a mute switch, and having a DI output level control that's independent of the master volume but still let's me have a post EQ DI send that includes the tube pre-amp goodness (maybe not as as easy as the HPF ).

improvements without changing the fundamental thing? (i'm assuming none of these are deal breakers on that end) i like it!

 

[kringle77]

On the tone side, the only thing I don't like is the relatively hyped and gloomy bottom. I use a Broughton up filter and it makes the amp clear, better od, a little more clean power.

 

[Al Kraft]

On the tone side, the only thing I don't like is the relatively hyped and gloomy bottom. I use a Broughton up filter and it makes the amp clear, better od, a little more clean power.

I think many of us deal with that problem at least occasionally with the Walkabout...that's why a built-in variable HPF is hopefully on agedhorse's "good idea list" for the Walkabout+.

 

[sratas]

Yep, a variable HPF , yes, yes, it has to be one of the added features

 

[Luke the Fluke]

Mute switch?
I personally don't think there's much wrong with the 300w - maybe a few tweaks to make it officially 2ohm stable. I guess the problem is the cab market has gone towards low tuned less sensitive cabs which want more than 300w.

This part is pretty clear, the challenge is how, and where it can go while staying as true to the original concept as possible.

The other part is where we might want to go with it given where the industry has evolved. Additional features for example?

 

[adam montminy]

I think all of these have been said before, but my list of updates would be:
1. 2ohm stable
2. a little more clean power available
3. speakons
4. quieter cooling scheme
5. better feet
6. adjustable HPF
7. pre/post switch
8. low profile fuse holder
9. Mute switch

Lastly, I would be a little disappointed if it ended up being class D, unless of course Andy can make it feel like the original.
Also, I'm a little surprised no one has mentioned the fuse holder. I had nothing but trouble with my WA until I had that fuse holder replaced with the low-profile type like they use on the newer Mesa heads. My amp kept shutting down randomly and I couldn't figure out why until I realized that the fuse holder would dislodge itself every time it got bumped, usually during transport in that soft bag. Maybe I had a bad one but it was a serious problem and when I took it to my tech, he said "That's a really really well-made amp, except for that stupid fuse holder." He also noted that the fuse holder is the only thing protecting those little switches on the back from damage so now I insert the head into the bag face-first. The amp has been flawless since I had it replaced.
By the way, I think this thread is amazing and I'm super impressed that Mesa's designer is here taking suggestions on how to improve an already amazing amp! This doesn't happen in other circles. I repair saxophones for a living and I can assure you that the major sax manufacturers are NOT engaging with players and looking for suggestions.

 

[kringle77]

A hp filter before the tube stages is a good idea. It not only cleans up the bottom but, since the tubes are being fed less lows to begin with, the od tone can be grittier, less farty.
I personally think that the semi parametric eq and treble are perfect but, I do find the bass control to be way too sensitive and quirky.

 

[sratas]

I tried placing a hpf (micro thumpinator) in the effects loop for recording purposes mainly, and it did a fantastic job. I think the result was much more noticeable because this placement assured that all the sub harmonics wich build up in the first gain stages are tamed or filtered away before reaching the back end.
The micro thumpinator did its magic even when placed before the input stage, but is was less evident, and, it eventually did modify the behaviour of the gain control, inducing a clipping and distortion with different flavours...can't say if I liked it more or less this way, but the sub filtering seemed more evident if the hpf was placed in the effects loop

 

[Al Kraft]

1. 2ohm stable
2. a little more clean power available
3. speakons

Completely agree and I took these three as automatic given agedhorse's design approach for the D-800/800+. I also can't imagine him ever designing/updating a bass amp for sale today that doesn't have Speakons and stable 2 Ohm operational capability.

Your total list is comprehensive and makes a compelling case for spending money when that improved product hits the shelves.

 

[McFarlin]

Loaded with all these extra features, it had better be no larger or heavier than the current version. And no Class D! But the fan has to be completely silent for when my post-minimalist meta-duo performs Cage's 4'33".
Additionally, you should offer the new version at an unreasonably low retail price. Keep the healthy profit margins on the guitar side (we can all agree, a Triple Rec. sounds way sweeter than $2,100).

 

[kevmoga]

"By the way, I think this thread is amazing and I'm super impressed that Mesa's designer is here taking suggestions on how to improve an already amazing amp!"

I second this! Really cool that Andy's willing to engage in these kind of dialogues.

I wouldn't argue with any of the additional features folks have suggested, but to me the biggest is the pre/post DI. I've added an Fdeck and am willing to work with a cab config to get 4 ohms. But the biggie to me is more clean power with that WA warmth - overdrive is not a tool I pull out of the box too often, if ever.

 

[the yeti]

just curious, did you guys that want clean try running the master full on and controlling the vol with the gain? still not clean enough?