Hello guys,
I'm trying to find a good article to understand how a A\B switches from each class. And I can't find anything the explains it completely. Does anyone know of a good article?
I have a X3 in the way. I read that it switches from A @15watts to B. I would like to know what that means. I'm not sure if it means if my speakers are 90db sensitive. At 8 watts I can get to 99db and still be at class A?
Thank you guys I really appreciate it a lot.
I'm trying to find a good article to understand how a A\B switches from each class. And I can't find anything the explains it completely. Does anyone know of a good article?
I have a X3 in the way. I read that it switches from A @15watts to B. I would like to know what that means. I'm not sure if it means if my speakers are 90db sensitive. At 8 watts I can get to 99db and still be at class A?
Thank you guys I really appreciate it a lot.
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I'm trying to find a good article to understand how a A\B switches from each class.
There is no switch. The circuit of a Class A amp and Class A/B amp can be identical except for the amount of bias. Lots of bias means that the amp must be physically big with a huge PSU, and large, very warm (read hot) heatsinks. This is expensive and inefficient, and is why most amps are not Class-A.
I'm not sure if it means if my speakers are 90db sensitive. At 8 watts I can get to 99db and still be at class A?
In theory, with your 90db speakers at 1M distance the SPL should be;
1W = 90db
2W = 93db
4W = 96db
8W = 99db
16W = 102db
32W = 105db
64W = 108db
128W = 111db
256W = 114db (yes, I know your amp doesn't have 250W)
So yes. There will be no klunk at 99db.
But much, much, much more important than the mythical klunk (which doesn't exist ) is by this computation, you have 10db headroom above your 99db target before the amp clips.
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8W into 8r0 requires an output current of 1.414Apk and an output voltage of 11.3Vpk...................... At 8 watts I can get to 99db and still be at class A?..............
To remain in ClassA @ 8W, the output stage must be able to output 1.414A of ClassA current.
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