gain block idea

Take the opamp and tip 41 headphone circuit that PRR posted and use it like a API gain stage into the API transformer.

sounds cool. Tamas have some similar circuit but using some buffer chips like LT1010(?) and BUF634.... and sounds very good.

Will try the TIP one. :thumb:

:sam:
Fabio

We did that sorts of stuff a lot almost two years ago. There was one with complemetary pair by Steffan as well. No single ended ones though. Lots of power goes to heat especially to drive a 75 ohm primary.

How about the GainBloke

Non-differential input, single ended output amp. The gain can be set through the usual opamp configuration.
No matching of transistors should be required. Lower the emitter resistors on the output to drive heavier loads. One of the numerous caveats, you need a capacitor on the output before coupling to a transformer because it is always at least 0.7 volt below zero potential.
Originally, I intended it to be used with a 1:4 OEP input transformer and an Edcor 600 ohm 1:1 on the output. It should work with BC550C/BC560C transistors.

Tamas

Tamas

I remember.

Thats why I was thinking about the SE headphone amp circuit.

Maybe for something a little different when overdriven.

Nelson Pass has a lengthy discussion someplace that single ended outputs sound "better" because single endedness is a more natural occurance in physics. This is all I remember. My eyes hazed over after the third paragraph. :sam: