A lot of class D amps need single polarity power supplies, e.g. ground and +30v. Finding a smps that works for you may be easier and more cost effective.
p { margin-bottom: 0.1in; line-height: 120%; } You can always use the transformer, and eventually also the rectifier bridge/buffer capacitors, for a new amplifier. It is only a matter of how much work it requires.
The Technics SA-EX500 is specified to deliver 65 watts per channel into 8Ω (stereo). 65 watt in 8 Ohm speakers means 23 volt RMS, which corresponds to some 37 V peak with a bit of overhead to drive the push-pull stage. Thus, it is likely that the Technics SA-EX500 power supply is symmetrical with a nominal value of around +/- 37V, and a voltage around +/-42V unloaded. If you can remove the loading from the Technics SA-EX500 power supply, then measure the voltage on the two (typically one for each rail) big electrolytic capacitors with a multimeter.
A +/- 42V supply (unloaded) is suited for amplifiers based on the TDA7293 class-AB IC. THD of 0.0050% typical! Such can be found from Asia at a very good price. Unless you are experienced with electronics, it is recommended to go for a class-AB amplifier because class-AB amplifiers are simple and cheap. And, if a class D amplifier misbehaves it is much more difficult to repair. You can probably also re-use the heatsink (remember insulation pads) from the Technics SA-EX500 for the new TDA7293 amplifier.
Good luck!
The Technics SA-EX500 is specified to deliver 65 watts per channel into 8Ω (stereo). 65 watt in 8 Ohm speakers means 23 volt RMS, which corresponds to some 37 V peak with a bit of overhead to drive the push-pull stage. Thus, it is likely that the Technics SA-EX500 power supply is symmetrical with a nominal value of around +/- 37V, and a voltage around +/-42V unloaded. If you can remove the loading from the Technics SA-EX500 power supply, then measure the voltage on the two (typically one for each rail) big electrolytic capacitors with a multimeter.
A +/- 42V supply (unloaded) is suited for amplifiers based on the TDA7293 class-AB IC. THD of 0.0050% typical! Such can be found from Asia at a very good price. Unless you are experienced with electronics, it is recommended to go for a class-AB amplifier because class-AB amplifiers are simple and cheap. And, if a class D amplifier misbehaves it is much more difficult to repair. You can probably also re-use the heatsink (remember insulation pads) from the Technics SA-EX500 for the new TDA7293 amplifier.
Good luck!
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