Adding a powered extension cab vs. adding another combo amp

[SmokinJoe992]

I recently purchased a used GK MB212 combo amp for $325 (the first version with the aluminum grill). I absolutely love the amp. The only downside is that there is no output to add an external speaker. It will only work with one of GK's powered extension cabs. While reading through older threads regarding the GK MB212 I saw someone posted that they used two GK MB212 combo amps together instead of using the powered extension cabs. To me this seems like the perfect solution. This would give you double the power and a back up amp on hand if something went wrong with the first one.
Without really understanding completely how this works, however, I have a few questions concerning this that I am hoping someone on here can help me out with.
1) Are there any disadvantages to doing this instead of adding a powered extension cab?
2) Do the combo amps need to be identical for this to work? (For instance could I pair a MB212 with a MB210, MB115, MB112, or even a Rumble 500)
3) Why would you get a powered extension cab over just buying another combo if the cost was close?
Thanks in advance for your responses and forgive me if these are "noob questions" or something that is covered frequently on here.

 

[Old Garage-Bander]

You are on firm ground.
Especially since you are starting with the big bad 212 version.
I can see where there might be advantages to start with a smaller combo and add a larger powered speaker.
But either way should work. And yes, having a full backup amp never hurts.

Where I think the powered GK cabs would really shine is if you had their Plex pre.
Then your options are D.I. or powered cab(s) of whatever mix you need, or both.

The advantage I see to the powered cab, is if you needed a really big stack -wall of sound- so to speak.
You can drive several powered cabs off of a combo or the Plex without being concerned with maxing out the impedance handling capability of the power amp.

 

[SmokinJoe992]

So could I pair this up with any other combo or does it need to be an identical one?

 

[mmbongo]

What exactly do you have again?

According to this picture, the older version does not have outputs for the powered cab OR an extension cabinet. It only has the DI connection (on top).

 

[SmokinJoe992]

What exactly do you have again?

According to this picture, the older version does not have outputs for the powered cab OR an extension cabinet. It only has the DI connection (on top).


View attachment 3010408

I assumed the powered cabs run off the xlr out

 

[SmokinJoe992]

If not then I guess running a second combo amp would be my only option. My only question then would be if the second combo needs to be identical.

 

[mmbongo]

I assumed the powered cabs run off the xlr out

No sir. The powered cabs will not run from a normal XLR. The output for the powered cabs does use a normal XLR cable, but the output voltage is something ridiculously high. Plus there would be no way to control the volume.

That amp does not have an output for chaining to another combo either.

You could get a GK Plex and run both a powered cab and your combo from it. Just set the levels on your combo and use the Plex for your master volume. That would also give you a tuner, compressor, and all the GK amp voicings as well.

 

[SmokinJoe992]

Aside from the tuner and additional tone options, would this be better than running another combo amp with it?

 

[Lobster11]

If you snoop around you'll find a number of threads about using two combos together. The way I did it (with a pair of Ampeg "Rocket" combos) was to split the signal -- I used a SansAmp BDDI, which has two outputs, and which I happened to have around -- and send one to each amp.

One advantage I found to this setup, that you couldn't get from adding a powered speaker, was that I put my effects/pedals in line after the signal splitter (SansAmp), so the effects went to the only one of the amps but not the other. This seemed like a great solution to the problem of bottom-sucking effects, because one amp always kept the deep booty while I was using effects through the other. Two disadvantages were that (1) there were two sets of volume and tone controls to deal with on the two amps, and (2) I got a nasty buzz from a ground loop. The short-term solution for me (since I was only using this dual-combo rig once) was to unplug the SansAmp and run it on batteries, but I'm sure there are more elegant solutions that would be better if you were planning to use this setup as a regular gigging rig.

 

[mmbongo]

Aside from the tuner and additional tone options, would this be better than running another combo amp with it?

I don't know about better, just different I guess. With two combo amps, you always have two combo amps and can use either one alone or both together. With the powered cab it would only work with the Plex or a GK amp designed to work with said powered cab.

Either way you would need a splitter pedal of some sort I would think. I don't know how else you would connect the two combos.

 

[garp]

To me this seems like the perfect solution. This would give you double the power and a back up amp on hand if something went wrong with the first one.

Well, technically speaking, it's not double the power. In theory, you're just moving twice as much air at the same power. I occasionally run two identical Fender Bassman 150 combos together. Each is 150 watts through an Eminence 12" plus a horn. It's not the same "oomph" as a single 300-watt amp. But to your point, I do love having that backup amp available.

 

[Wasnex]

Well, technically speaking, it's not double the power. In theory, you're just moving twice as much air at the same power. I occasionally run two identical Fender Bassman 150 combos together. Each is 150 watts through an Eminence 12" plus a horn. It's not the same "oomph" as a single 300-watt amp. But to your point, I do love having that backup amp available.

Sorry, but this is not correct. If you add a second identical combo amp, you do indeed double the power. Additionally, the combined rig should be capable of producing 6db more SPL for the range of frequencies in which acoustic coupling is near perfect.

That doesn't mean two 150 watt combo amps will be louder or sound better than your 300 watt amp...other factors must be considered besides power.

 

[garp]

Sorry, but this is not correct.

Thanks for the correction.

 

[Downunderwonder]

It's the old mixing cabs poser dressed up in a fancy combo suit.

If you get the matchIng extension powered gizmo you know what you're getting. Likewise an identical combo. Anything else is trial and error.

 

[packhowitzer]

The MB Combos with the silver grills have no ability to connect to the MBP powered cabs. For that you need the MB-II Combos with the black grills. There is an XLR jack on the back of the MB-IIs that says "Chain Out". you can link up to seven extension cabs before the signal gives out.

I have an MB115-II and an MBP115 and the sound is pretty thunderous for the size/weight/price:

However the older Silver MB210 does allow for a passive 8ohm extension cab to be added. The amp by itself send 200 watts to the 2 10s. When you add a cab using the speakon connector, the amp puts out 350 watts.

 

[packhowitzer]

When I need to run one instrument into two amps without losing any signal- this is what i use. It's kind of pricy compared to a splitter, but it works VERY well.

 

[ColonelZulu]

I use a Radial too for running two amps. The Switchbone is great, but the BigShot is less expensive and does all you need (phase, ground lift, line select or both, tuner output).


https://media.sweetwater.com/api/i/...es/items/750/BigShotABYv2-large.jpg.auto.webp

 

[Bald-N-Bassy]

If you snoop around you'll find a number of threads about using two combos together. The way I did it (with a pair of Ampeg "Rocket" combos) was to split the signal -- I used a SansAmp BDDI, which has two outputs, and which I happened to have around -- and send one to each amp.

Exactly what I do. I have the Sansamp and the MXR bass di +. I like that only one combo has a wet signal & the other is receiving a dry. The volume and EQ is a breeze for me. I just start flat and adjust to the room im playing in. Currently Im running either a GK MB115-2 and Rumble 500C.

 

[Bald-N-Bassy]

@SmokinJoe992
2) Do the combo amps need to be identical for this to work? (For instance could I pair a MB212 with a MB210, MB115, MB112, or even a Rumble 500)

No, they can be different. 2 different combos can give you a wider tone palette. 2 of the same could be eq'd differently. Or run one wet and one dry.

3) Why would you get a powered extension cab over just buying another combo if the cost was close?

One advantage I see is the ease of getting the same tone and volume from the Master combo. When running 2 combos. You have 2 amps to EQ and set the volume on. Not a hard task, but with the MBP cabs you just connect and adjust on your combos EQ and volume.

 

[LowActionHero]

I used to run 2 MB115'S.
I'd do it again.
And maybe once more after that.
But that's it.