In article .com,
wrote:
I hoped that some cheap BD441/442 transistors might be sufficient for
me to find out if the rest of the circuit was OK. They are at least
rated for the voltage (73 volts rail-to-rail). But putting them, and
new 0.27R resistors, in the circuit and powering-up resulted in smoke.
I guess their characteristics (higher gain, lower current) are too
different, or there's something else wrong with the circuit. At least I
only blew up a few pence/cents worth of components.

Any suggestions about equivalent transistors at sensible price? Any
ideas how I can try things out while minimising the chance of more
fireworks?

The power amp appears to be direct coupled so I'd guess a few blown up
transistors back down the line too.

--
*Women who seek to be equal to men lack ambition.

Dave Plowman London SW
To e-mail, change noise into sound.