Pete Cross wrote:
You did say you where a soundman didn't you ?

Not heard of watts equal v squared over r ?

eg an amp powered off 9v battery into an 8ohm spkr will give almost 10w
providing it can draw enough current and can drive rail to rail. Does your
outboard have a generator that can charge a car battery ? you could mount a
cheap car radio cd player that supports mp3's or even has an input for an
ipod which would be good for 20w/channel.

Pete



Sounds like you have mistaken 9v DC for 9v AC. Quite a difference. An
amplifier running off a 9volt rail can output 8v p-p at best (2xVbe have
to be taken off the maximum rail voltage). 8v p-p is 2.83v rms which
into 8 ohms is 1W. There are techniques used involving DC-DC converters
which can increase the rail voltage, bridge connection and/or output
transformers which reduce the load impedance as seen by the amplifier,
but for a straight single-ended transistor amplifier driven from a 9v
rail, 1W is the best you'll get into 8 ohms.

S.