Discrete op amp headphone amplifier module, based on Marantz

[rjm]

** This is just a design idea and simulation to play with, the circuit is not guaranteed to be either stable or safe **

That said, it seems to be running well on the virtual bench.

Comments appreciated.

 

[00940]

Rather weak output transistors, no ?

 

[peranders]

You can play extremely high with those.

 

[rjm]

@00940

Transistor selection in LTSpice is lousy. I'd nominally be looking at BD135,136 or similar TO126 or TO220 types.

@Per

No kidding! Do we need 80 mW of low distortion class A power? Certainly not. But, we can get it from a thermal budget of 5~10 wpc idle draw, and this is not impractical to design for. Consider the output bias current to be highly "user variable".

 

[00940]

@00940

Transistor selection in LTSpice is lousy. I'd nominally be looking at BD135,136 or similar TO126 or TO220 types.

It is... have a look at Cordell's models , he has correct ones for bd139-140 (as well as other suitable transistors, usually used as drivers).