Hi, first post here.
IM trying to optimise an emitter follower to drive my high impedance headphones.
I have researched and tried a fair amount of different amp topologies e.g op amps, discrete, semi discrete In the end the best sounding design was Class A emitter follower, no gain, as simple as can be.
I am using BD139 currently and was wondering about replacing it with something else Thanks to low current requirement of high impedance headphones there is a much broader choice of BJTs, and suspected some of the lower current devices may offer better performance is that the case?
What should I look for in a BJT for emitter follower for lowest noise and distortion? High hFE?
im current running 100ma quiescent current on 12V supply. I may increase supply voltage to 20V at the max but I dont listen very loud and it keeps transistors cooler.
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