Volume and Output Stages

[Punch n' rumble]

Hi, everyone!

I've got a question about volume and output stages. I tried the search engine and Google but didn't find an answer.

So, I'll be upgrading from a combo setup to a head and cabinet setup and the head I'm thinking of getting (a Trace-Elliot head) runs at 1200W. That's 2 x 600W (4 Ohms) output stages.

What I'd like to know is what that means exactly because I'm not sure I understood correctly. Does it mean that it can run at both 600W and 1200W? The "two output stages" part got me a bit confused.

Thanks and I'll be looking forward to your replies!

 

[JimmyM]

It means it has two separate power amps built inside the head, each putting out 600w @ 4 ohms, and you can combine them (bridged mode) into what's effectively a single power amp that I'm guessing runs at 1200w @ 2 ohms (not familiar with that model but that's the way they usually do it).

 

[BassmanPaul]

No jimmy, if the amp has 600W at 4Ω it can bridge for 1200W at 8Ω. To bridge at 4Ω the amp has to be 2Ω capable per channel. If not bridging it so will destroy the amp.

Paul

 

[JimmyM]

Thanks for the clarification Paul. If that's the case, though, what would be the point? 1200w at 8 ohms? Sorry, I'm not feeling that one. I think either the description is wrong, or this amp is a white elephant. What's the model number, Punch?

 

[BassmanPaul]

As you know SS amps will give more output the lower the impedance presented to it. Now what happens if say a guy goes from a tube amp to SS. If he owns an eight ohm cabinet. His amp will not give its full output into 8Ω. By bridging his amp he can get much more power into his cabinet. When you bridge you have four time the power available but each channel "sees" half of the impedance connected. Thus if you have an amplifier that is capable of 4Ω operation per channel you can only bridge into 8Ω. You will get twice the individual channels power into the load. If 2Ω/ch then you can bridge into 4Ω and get twice the 2Ω rating of each channel.

Paul

 

[Punch n' rumble]

Thanks a lot for the replies, guys!

Jimmy: The model name is: AH1200-12 Head

Paul: I asked a bass player friend of mine yesterday and he told me the same thing you said regarding the amp being run at 2 ohms and getting destroyed.

As for the purpose of this feature... as Paul said, is it so that the amp can be run in SS mode without losing volume? That would be a cool feature, I guess. I'll see if I can download the manual for this model. I should have thought about this already.

Thanks a lot, guys!!