In article , Ethan Winer says...

Elfa,

I want to match the impedances by making my own small audio transformer

I'll go out on a limb and say that a home-made transformer will probably
have more losses (and other problems) than any efficiency gain you could
possibly hope for. This is not to discourage you from experimenting! Go
ahead and make the transformer anyway. But don't be disappointed if it
doesn't work well.

You mentioned having a toroid ring. Audio transformers need to work over a
wide range of frequencies. Is your toroid meant for audio, 60 Hz power, or
radio frequencies?

--Ethan


I have no idea what the toroid was originally designed for....I just bought a
handful of them at an electronics discount house. I used one for a balun (used
in shortwave antennas for impedence matching cable to plain old copper wire).
The toroid is about 1 1/4 inches in diameter.

The amp has an 'input' of 450 mV and a max output of 2W. The speaker is 8 ohm
and max of 6W. Without impedence matching, my little low power amp over drives
the speaker. I just want to reduce the distortion. I'm not an audiophile so I
really don't care about the 'perfect' sound system. I have a hearing disability
and the whole point of this project is to listen to my small radios (shortwave)
with their tiny speakers without the frustration of not understanding what I'm
hearing.

Now....can you tell me about the number of winds needed? To experiment, I need
to start somewhere.

thanks

elfa