Two heads to one cab?

Re: Two heads to one cab?

Amateur said:
Most of the power amps in the market have that option right now.
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Yes, but remember that those stereo power amps are on the same power supply and are designed to be bridged- if you connect two heads to one cabnet, and it isn't a stereo cab you will surely blow stuff up-
btw have you ever seen a speaker catch on fire? makes a cool stage effect, but drains the pocketbook- and may cause you some physical damage
you can get the tonebone switcher- but I'm not sure how it works-
you can run two heads into one cab- but not both on at the same time, it's an either/or situation.
 
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Re: Two heads to one cab?

How do two heads running at the same time in a stereo cab sound when played at the same time?
 
Re: Two heads to one cab?

greendy123 said:
How do two heads running at the same time in a stereo cab sound when played at the same time?
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umm- sounds like a stereo amp setup-depends on the two heads- and their tone configurations, and how you have them set-this is a hard question to answer, they would be more noticable if you were running them with a stereo delay or chorus, one side into each amp-
 
Re: Two heads to one cab?

fuzzyratfarts said:
How?
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www.axess-electronics.com HS2.... the HS2 is amazing! Works for 2 Tube heads so you can A/B between them.... I own the HS2 so i can a/b between my 5150 head and a Classic 50 head... The C50 is my clean channel basicly... with that system i have a 4 channel set up.....

The HS2 has some downsides... one-you can't use Delay in the amps FX loops as the echo keeps sending signals to the head on standby with no load. 2-you can't really use OD's or Distortion units in front of the HS2 to drive the amps more.... The HS2 is just to pick between 2 nice amps.... only FX's i use with it is a chorus and a Wah plugged infront of the HS2....

Axess now also has a larger amp switching system that allows delays and stuff i think.... Great products!
 
Re: Two heads to one cab?

marvar said:
Yes, but remember that those stereo power amps are on the same power supply and are designed to be bridged- if you connect two heads to one cabnet, and it isn't a stereo cab you will surely blow stuff up-
btw have you ever seen a speaker catch on fire? makes a cool stage effect, but drains the pocketbook- and may cause you some physical damage
you can get the tonebone switcher- but I'm not sure how it works-
you can run two heads into one cab- but not both on at the same time, it's an either/or situation.
Click to expand...
The power amps are stereo bridged to mono, so the mono cab should work. A single power supply in a stereo power amp does not guarantee equal power going into both amp sections, ther is still some regulation invloved. It may be a little bit more complicated if you have different power supplies for the amps, not sure for tube amps, but it is definitely workable for solid state amps. You just have to design it right and you may need some modification on the amps, which you may not like it.
 
Re: Two heads to one cab?

Amateur said:
A bridge to mono. That's how they do it in power amps.
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If you Bridge 2 SEPARATE amps to each other, you´ll almost certainly send both of them to the moon...REAL bad idea...

Am amp is either designed to be bridged, or it isn´t ... I don´t know a single HEAD (read the thread title) that can be bridged at all, much less one that can be bridged with another head.

Bridging Power sections requires them to be on the same power supply.... it´s easy inside of a single rack unit, becasue there you´re just taking the signal that you previously split internally and merging it again.... Not so easy when the signals were never the same in the first place and you´re running separate amps....

You´ll need either 1 amp per cabinet half (assuming you have stereo inputs), or you can use an Amp switcher f you don´t need the m simultaneously ;)
 
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Re: Two heads to one cab?

I still say the HS2 from www.axess-electronics.com is the safe-ist way of doing this.... I use mine a lot.... you just have to make sure all power cables and speaker and guitar cables are hooked up right before turning anything on...

Only thing is you can't use with this set up is Delay fx's in the FX loops of the amps... One one head is on standby the other is on.... If you had a delay in the standby head your delay is still sending signals to an amp that has no speaker load... The HS2 is killer when it's all set up!
 
Re: Two heads to one cab?

Zerberus said:
If you Bridge 2 SEPARATE amps to each other, you´ll almost certainly send both of them to the moon...REAL bad idea...

Am amp is either designed to be bridged, or it isn´t ... I don´t know a single HEAD (read the thread title) that can be bridged at all, much less one that can be bridged with another head.

Bridging Power sections requires them to be on the same power supply.... it´s easy inside of a single rack unit, becasue there you´re just taking the signal that you previously split internally and merging it again.... Not so easy when the signals were never the same in the first place and you´re running separate amps....
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I am not saying it is a piece of cake, it is definitely a challenge. I may have to modify the two amps so that they can use only one requlated power supply when the two amps are bridge. This is much easier for solid state amps but a headache for tube amps. That's why I said I weren't sure about tube amps. I'd done this in the lab on two low power transistor amps that I had hooked up and so I know it is possible.
 
Re: Two heads to one cab?

Combining 2 separate mono signals (or two separate heads) is not the same as bridging an amp or amps- That is merely paralleling two outputs, and effectively adding the combined wattage of each amp to your speaker-which most speakers arent' made for, at least most guitar speakers-
When you bridge a stereo power amp, you use only the designated positive output from each side-effectively doubling the output voltage-and making it a mono output-that is why it is so important that the stereo amp is working off of the same internal power supply- and I don't mean a regulated power source-also when you bridge a power amp, you have to be very careful of the ohm load- for instance, if your stereo amp is 100 watts at 4 ohms per side, when you bridge the two sides, you get a mono 200 watts into an 8 ohm load-if you go lower than 8 ohms, you will most likely fry your outputs. I sometimes wish power amp makers had never included this feature as it is sorely misunderstood. The only instance I can think of for bridging an amp is in professional sound systems, or if you are using a 75 volt line, as in pubic address systems in large buildings. (But keep in mind, all the speakers on the line have an individual transformer)
Yes, I too have combined the outputs of 2 low power transistor amps- like a stereo boom box- but sooner or later, it will give out- and if you attempt two combine the output of two separate high power amps- you will most likely blow the speakers, in turn, shorting out your amp outputs- but, if you are determined to try it, go ahead- there are plenty of electronics techs out there that will be glad to take your money, to correct your mistakes-
 
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Re: Two heads to one cab?

marvar said:
Combining 2 separate mono signals (or two separate heads) is not the same as bridging an amp or amps- That is merely paralleling two outputs, and effectively adding the combined wattage of each amp to your speaker-which most speakers arent' made for, at least most guitar speakers-
When you bridge a stereo power amp, you use only the designated positive output from each side-effectively doubling the output voltage-and making it a mono output-that is why it is so important that the stereo amp is working off of the same internal power supply- and I don't mean a regulated power source-also when you bridge a power amp, you have to be very careful of the ohm load- for instance, if your stereo amp is 100 watts at 4 ohms per side, when you bridge the two sides, you get a mono 200 watts into an 8 ohm load-if you go lower than 8 ohms, you will most likely fry your outputs. I sometimes wish power amp makers had never included this feature as it is sorely misunderstood. The only instance I can think of for bridging an amp is in professional sound systems, or if you are using a 75 volt line, as in pubic address systems in large buildings. (But keep in mind, all the speakers on the line have an individual transformer)
Yes, I too have combined the outputs of 2 low power transistor amps- like a stereo boom box- but sooner or later, it will give out- and if you attempt two combine the output of two separate high power amps- you will most likely blow the speakers, in turn, shorting out your amp outputs- but, if you are determined to try it, go ahead- there are plenty of electronics techs out there that will be glad to take your money, to correct your mistakes-
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You're absolutely correct. I would use only one power supply from either of the amps but it will have different regulated potentials going to the two amps because the two amp circuits may rquired different voltages to operate. The bridging circuit needs the impedence of the speakers to be double or the sum of the amps' reqular requirement. Come to think of it, I may even have to get a bigger power supply. All these need a careful design and is not for the novice. I am not saying everyone can do this but it is possible except you have to do major surgery on your amps. I wouldn't do it myself because I don't see the need for it. If I do, I'll have the engineers and technicians in our department do it. We have an electrical lab and some of them do design and build sound equipment for a living. It is nice when you have all those resources.
 
Re: Two heads to one cab?

Amateur said:
You're absolutely correct. I would use only one power supply from either of the amps but it will have different regulated potentials going to the two amps because the two amp circuits may rquired different voltages to operate. The bridging circuit needs the impedence of the speakers to be double or the sum of the amps' reqular requirement. Come to think of it, I may even have to get a bigger power supply. All these need a careful design and is not for the novice. I am not saying everyone can do this but it is possible except you have to do major surgery on your amps. I wouldn't do it myself because I don't see the need for it. If I do, I'll have the engineers and technicians in our department do it. We have an electrical lab and some of them do design and build sound equipment for a living. It is nice when you have all those resources.
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Yea! finally I've found someone else that understands bridging amps!
ROCK ON! and I think if I were you, I'd change my nick, you are def not an Amateur!
 
Re: Two heads to one cab?

marvar said:
Yea! finally I've found someone else that understands bridging amps!
ROCK ON! and I think if I were you, I'd change my nick, you are def not an Amateur!
Click to expand...
I still think I don't know enough.
But, :beerchug:
 
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