Separate IPS and OPS boards?

[Neutrality]

Thinking about making an amp with separate input stage and output stage boards. Like the attached OPS.

Would make it easy to experiment with different Input stages.

Totally crazy? Any drawbacks?

[Pingrs]

See OS(tripper) He does that!

[effebi]

I like the idea and your PCB design (eagle?) . What about thermal compensation/bias adj? And V-I limiting?

[Neutrality]

Originally Posted by effebi

I like the idea and your PCB design (eagle?) . What about thermal compensation/bias adj? And V-I limiting?

Yes, Eagle. There will be no V-I Limiting and the whole Vbe multiplier will be on the input stage boards. The Vbe transistor itself will be mounted on top of one of the output transistors.

It is just an idea for now but I quite like it.

[effebi]

Originally Posted by Neutrality

Yes, Eagle. There will be no V-I Limiting and the whole Vbe multiplier will be on the input stage boards. The Vbe transistor itself will be mounted on top of one of the output transistors.

It is just an idea for now but I quite like it.

My notes were driven from the fact that such a "modular" design would be useful in a PA-like amplifier ( a goal that I am pursung from a while ) and there some kind of protection might be necessary. One possibility would be to bring out as a measure point just the voltage across the two Re.The protection would be then demanded to another module, either the input itself or a dedicated one.

About the Vbe transistor, bringing it back to another module with wires, aside that not so "elegant" (complicate disconnection of the boards, etc) is prone to induce oscillations if wires are going to be likely long.
Maybe an approach with diodes (Leach-like) is preferable. Anyway Vbe is not an option.
So, as usual, a lot of design compromises... But please keep going, I believe your approach is very good!
BTW, why "bent" power resistors? Do you want to improve airflow from a fan?

[Neutrality]

Originally Posted by effebi

My notes were driven from the fact that such a "modular" design would be useful in a PA-like amplifier ( a goal that I am pursung from a while ) and there some kind of protection might be necessary. One possibility would be to bring out as a measure point just the voltage across the two Re.The protection would be then demanded to another module, either the input itself or a dedicated one.

About the Vbe transistor, bringing it back to another module with wires, aside that not so "elegant" (complicate disconnection of the boards, etc) is prone to induce oscillations if wires are going to be likely long.
Maybe an approach with diodes (Leach-like) is preferable. Anyway Vbe is not an option.
So, as usual, a lot of design compromises... But please keep going, I believe your approach is very good!
BTW, why "bent" power resistors? Do you want to improve airflow from a fan?

Well I might end up dropping this idea for now and go with a more conventional one board design but for future designs it should be worth looking into.