"MK"

This will do it.
http://cpc.farnell.com/_/bt936/louds...all/dp/AV01580

It's a transformer-based design (presumably a variable auto-transformer,
like a Variac). A bit more expensive than a couple of 5-10 watt
resistors, but the extra flexibility is worth-while.

There is something odd about that part - a pair of audio transformers
rated 60W with 20Hz to 20kHz response in package 140mm x 85mm x 45mm - and
variable as well - and for £20. Don't expect it to sound very good.


** Expect it to blow your amplifier.

Here is a nice pic of the insides:

http://www.avstorm.co.uk/Switch_boxe...36_17 63.html

Consists only of a multi-position switch and 2 tiny auto-transformers.




...... Phil