Hi

I'm finally looking at the details behind making use of the S76477 sound generator.

Most of the circuits in the data sheet use a 2N3703 transistor as part of the output; however I'm unable to get them at my usual places. What would be a suitable alternative or is there simply a different part number for the transistor?

http://docs.bgmicro.com/pdf/ics76477a.pdf

Also what changes would be needed (if any) to use a 16ohm speaker rather than an 8ohm.

Thanks.

Nick.

 

A 2N3906 should work fine for you. Everybody sells them. FWIW- Futurelec sells the 3703 and the 3906.
Looking at the circuit diagram, there is a 100 ohm resistor labelled "R loud"
in series with the 8 ohm speaker and the driver transistor. To switch to a 16 ohm speaker you will need to make R loud 8 ohms less.