2 heads?

[sk8bobby10]

ok, so, i heard something about plugging 2 heads into one cab for like band practices and stuff so you dont have to lug around a huge cab with you. I mentioned this to the other guitar player in my band and he had a huge rage how it would blow his speakers out and yadada... But i mean if the ohms matched up and the combined wattage for the heads wasnt too much for the cab, wouldnt that work? Please help me guys.

 

[tourettes5139]

Sounds like a bad idea to me.

 

[Outlaws]

IF its a stereo cab and you understand how to hook it up, and you understand how the watts handling will be split, and how the ohms will work, it could be done. Outside of that you shouldn't do it...and to be honest, you shouldn't do it anyways because it isn't your cab.

Most cabs, IF they are stereo, are 4/16 ohms mono and 8 ohms stereo. meaning both inputs would need to be 8 ohms. then the watts the cab hndles...say a marshall cab rated at 350 watts....would then accept 175 each side.

What cab are you planning on doing this too? remember that just because there are two plugs back there doesn't mean its stereo....that is for daisy chaining cabs to the amp...not the other way around.

 

[sk8bobby10]

its a fender, 8 ohms, 350 watts, thats all i really know...

 

[Outlaws]

its a fender, 8 ohms, 350 watts, thats all i really know...

412? I would ask your friend if it has stereo inputs...and be specific in stereo, not just two inputs.

If its a 212 cab then its two 16 ohm speakers probably that make an 8 ohm mono cab.

 

[sk8bobby10]

k, cant thank you guys enough for all the help around this site.

 

[Outlaws]

Too bad it isn't your cab. With a little soldering and a couple cheap parts you could easily rewire any multi speaker cab into stereo operation There are schematics and diagrams on the net. It would just be a matter of your heads having enough options for ohms (4, 8, 16) to accomidate whatever the new stereo cab would need.

 

[Adam P]

Like others have said, unless its a true stereo cab, I would avoid attempting this. If it simply has two jacks on the back, chances are that they're simply wired in series for daisychaining cabinets. If you plugged a different head into each jack simultaneously, you would, I believe, be in effect plugging the output jack of one of the heads into the output jack of the other, which I can't imagine is anything but very bad for all involved.

 

[BrentDomann]

I'm totally going to sound like two things:

A) Not a metalhead
B) A jerk

But anyway, I think this is a clear example of why combo amps, if chosen carefully and correctly for their application, can be a great option.

I, like you, got tired of lugging a 4X12" around. So, at about a day's notice to myself, I went out and just dumped the cab, head, and some other gear for a good tube combo. It's still a bit heavy, but much less to lug around. For what it's worth, it sounds a hell of a lot better too. And more importantly, I don't have to deal with messing around on other people's stuff (which affords me the option of telling them to keep their mitts off of mine).

That being said, I probably wouldn't attempt the two-head thing. It might be worth it just to leave your cab at the practice space or to try to get a used one or a cheap one to leave there. But, if money is tight, you picked the amp. Just lug it.

 

[Light]

IF you want to do it, you need to get something to switch between the heads, you can't just leave them both active to the cab at the same time, because the two trannies will mess up the impedance for each of them, and you will fry your tranny (in all likelyhood, though it might work for a while). There are a couple of things out there for this, though.

Check out the Axess Electronics HS-2. That is the less expensive version, at about 275 (so less than the second cab anyway).


Bob Bradshaw can also do something for you, but it would be custom order, and very spendy. There are probably others out there as well.


And as you've probably noticed, you can't use both heads at the same time. The trannies are seeing each other in parallel with the speaker, so you are lowering the impedance of the load, which is the surest way to fuck up an output transformer you are going to find.



Light

"Cowards can never be moral."
M.K. Gandhi

 

[Light]

Reread your post, and it looks like you want to put two guitar players into one cab. That's not gonna work.


You see, if you've got an 8 ohm OT and a 8 ohm speaker, adding another load (such as a speaker, but the OT's would look exactly like a speaker to each other), you NOW have an 8 ohm trannie driving a 4 ohm load.


And that is assuming the power coming from the other tranny does just blow both the OT's in the first place.


So actually, I would guess that the speakers would be just fine. Mostly because they would never see any signal, as the OT's would both melt first.



I wouldn't try it, myself. Output Transformers are expensive.



Light

"Cowards can never be moral."
M.K. Gandhi

 

[tarnationsauce2]

It is possible, but it is somewhat advanced.
If you attempt it, be sure the cab is set for stereo operation.

I had a friend many years ago that played through 2 Marshall heads.
Normally he played 2 4x12 cabs, but scaled down for a show. So he brought only 1 4x12 cab, but it had a mono/stereo switch.
So he flipped the switch to stereo and plugged his heads in.
Turned on the heads, and started setting gain.

Then POOF_ZAP_FIZZZZZ_POP!

He had have a slew of components replaced, had the not been Marshalls they would have been worth more as trash. Needless to say after that he used 1-head-per-cab no matter what.

Turns out the problem was that the stereo/moino switch was bypassed... probably by a previous owner.