audio driver for more current and dual supply

[Mark Amundson]

Martin Czech wrote:
> I need a driver that is able to source 200mA to 500mA at audio
> frequency. E.g. reverb coil driver, magnetic  core driver, little
> speaker driver. I had a look at all these TDA audio amps (for car radio
> etc.) but they all use only a single supply. Does somebody know a
> convenient solution that uses both power rails ?  There is a
> possibility to boost a normal op amp, add npn and pnp in collector
> circuit, the driving and biasing is done by the opamp supply pins and
> two restors attached to these.  Anybody tryed this? Any help appreciated.
> m.c.

Consider using a LM1875 Audio Power Amplifier IC. It is made to run on
split supplies and does about 10 watts at 8 ohms with +/- 15 volt rails.
Will run down to 4 ohm loads as well. It draws about 50mA quiescent and
is in a 5 pin TO-220 package for modest heatsinking. I just built a
professional grade headphone amplifier using a pair of these chips.
Plenty of dynamic range and offer good punch on regulated power
supplies.

Mark Amundson,