Class A performance of BHK 250


After how many watts does the BHK 250 transition from class A to class AB? Or, how many watts of class A does it produce?


From a reply to a question that BHK himself answers:

emailists said What was the answer regarding the exact Wattage of class A? Is it in fact 40 watts?

It is about 1W into an 8 Ohm load. Every increase of idling current of a factor of 1.414 will increase the class A power by a factor of 2. By doing this, it will quickly increase the heat sink temperature to values that will shorten the life of the components inside the amp. As I have said in a previous post, the sound of this circuit is surprisingly independent of the actual idling current and class A power within reason and the idling current it is set at makes for exceptional sound and reliability.





Thank you.


Wow, interesting, I wouldn’t have expected that low Class A output, but on the other hand the high wattage tells why.

My pure Class A amp at the time was double as big and had 2x 100 or 150W. And it was hot.