Mod a badlander to have an overall master volume?

[spawnofthesith2]

I’m sure this seems like a dumb proposal, but I’m curious, how feasible/possible would a mod like this be? I’m sure this sounds dumb to 99% of people, but I have a hyper specific use case that having an overall master would be a complete game changer. I love this amp, but the location of the channel masters in the circuit cause some rather significant issues with live performance for my situation….

 

[rarebitusa]

I run a vol pedal in the loop, would that work for you?

 

[TheDeepBelow]

You can also use something like the JHS little black box in the loop. These can be built for cheap.

 

[solderhead]

I feel your pain. To avoid it I run an old design 3 channel amp (Mark IV) that has a great big global master volume knob in a very convenient location on the front panel -- something that's so big that it stands out.

That eliminates the problem of tweaking 3 different channel masters to get the levels balanced, which is decidedly inconvenient in a live setting. It's much easier to get my levels balanced beforehand, and just turn up the global master volume to accommodate any level changes that are necessary when performing. This saves me from the unpleasant experience of trying to tweak an amp that has too many interactive little knobs to allow dialing it in on the fly. (These later Mark amps can really end up sounding like ass if they're not precisely dialed-in.)

I don't understand why Mesa now gives us independent channel masters without a global master. Eliminating the global master seems to have happened when they started adding separate solo masters. Maybe they just ran out space when designing the front panel interface. The problem is that when you design an amp in a lab, it's an entirely different experience than using it on stage.

Although I guess one could say that you don't need a global master in a 2 channel amp, I've noticed that they've eliminated the big global front panel master control from the Mark V, JP-2C and VII. This makes no sense to me. On the V, there's global master but it's tiny. On the JP-2C and VII it's gone. It's as if they've gradually assigned less importance to a global master from one generation to the next, to the point that they just decided to eliminate it. I think that was a misteak -- I view the easy-access / big-knob front panel master as being so valuable that I won't consider "upgrading" to a newer Mark series amp. To me those front panels took a number of wrong turns as Mesa went from generation to generation.

All that is just a long way to say that I completely agree with your assessment that a global master is a must-have feature for an amp.

Would it be possible to mod your amp? Sure. Anyone competent at amp work can modify any circuit to add a global master volume. The real questions are who can do it for you, and where to put the knob. If the designers left you with a layout that gives you no place to put the knob then you're kinda screwed.

The problem with sticking a pot in the loop is that you can run into impedance matching problems. If you put a volume controlling device in the loop it really needs to maintain a high input impedance and a low output impedance so that it doesn't load down your loop. I'm not familiar with your amp's loop design, but I'm thinking that that sort of device really needs to be active/buffered rather than just a pot in a box.

 

[rarebitusa]

I'm not familiar with your amp's loop design, but I'm thinking that that sort of device really needs to be active/buffered rather than just a pot in a box.

I'll weigh in for the sake of conversation.

Since I run a multifx pedal in 4CM live, a volume pedal block is routinely part of the signal chain. It works really well. Most of my Mesas have a global master vol, but the more recent addition of a Badlander doesn't and that did take a bit of rethinking with the volume pedal block usage and setup. Now it's seamless.

I don't understand why Mesa now gives us independent channel masters without a global master.

So I'll totally speculate... the V:90 generated alot of complaints with the loop tone suck and that loop was integrated with the Global Master Vol. It seemed amps released after the V:90 saw that part of the design dropped. I agree that not having one with a 3 Chan amp does complicate things further especially live.

 

[solderhead]

Thanks for explaining the problem with the V:90 -- I was not aware of it.

When I first got my Mk IV around 1990, I used a 70s Morley Power Wah/Boost pedal in volume/boost mode to reduce my loop send volume so that I wouldn't overdrive my input-sensitive buffer brigade type effects, and another one at the back end to boost the return signal back up to where it was before I reduced it. Without a volume send control in the loop it was easy to have the clipped preamp signal voltage be large enough to overdrive the inputs on my time-based effects and they sounded like garbage. I had to reduce the signal for the FX chain, and boost it on return for the amp. Unfortunately the amp wasn't designed with send and return volume controls so I had to supply my own.

I tried using those pedals as an experiment just because I had them and wanted to experiment. Because they're active pedals and buffered, I avoided the tone suck problem. Any clean boost pedal should work the same way. If having foot control isn't mandatory, or if one just prefers a knob, I guess you could use a simple buffered clean boost pedal like the MXR Micro Amp in lieu of a volume pedal. The key is that whatever device you plan to use needs to be active (not just a passive pot-in-a-box) so that an impedance mismatch doesn't result in the dreaded tone suck.

As the years have gone by, better amp designs began to offer send and receive volume controls to help avoid these problems. A lot of the time, it's easy to overcome the weaknesses of an amp's poor FX loop if you understand where the problem lies.

 

[spawnofthesith2]

I run a vol pedal in the loop, would that work for you?

You can also use something like the JHS little black box in the loop. These can be built for cheap.

Unfortunately not, as the channel masters are post FX loop, so anything in the loop doesn’t solve my specific issues

 

[rarebitusa]

I tried using those pedals as an experiment just because I had them and wanted to experiment. Because they're active pedals and buffered, I avoided the tone suck problem.

Yes, exactly. I carefully tuned the I/O levels for the V:90 loop and that took time and patience. I can see however why some would run into issues and that could be frustrating. The V:90 was a bit finicky. I do think the Global Master Vol is really a requirement on a 3 chan amp.

 

[rarebitusa]

I love this amp, but the location of the channel masters in the circuit cause some rather significant issues with live performance for my situation….

I'm curious... what specifically? I'm not trying to be a PITA indeed the fx loop is before the chan masters but if you locate the vol pedal at the end of the signal chain it kinda does the same thing?