HiFi audio amplifier using Burr-Brown op amp

“Burr-Brown is known as an industry leader of high-precision, audio quality op amps. These ICs can be used in a variety of audio applications.” I am using OPA541 in metal TO-3 package. Continuous current output 5A (10A peek), internal power dissipation 125W … And it is using +-40V (80V) power supply. It gives lots of power for audio amplifier. And the quality of such power amp is very very good. I am using 4 chips, so I can bridge them or connect in parallel. The power supply for this monster must be powerful too. It is still under construction- now it is modified ATX. It gives me +-40V (80V total), but only 2A… Must redesign it… but current PSU is powerful enough to make my S-70 loudspeaker jump. And I love calm music. So all fans and radiators are useless.

The schematics are not complicated, even novice cam build it. I am using Texas Instruments (owner of Burr Brown) technical article No: SBOA082, here is part of schematics:
Free Power Amp schematics

I divided schematics to 2 parts: one- preamp (is using computer as a source, pre amp is not useful) and power stage. Power stage is made from SMD parts to minimize the wire length and reduce possible layout problems. Here is photo of PCB:
PCB of HiFi audio power amplifier
See lots of ceramic capacitors on power lines and find black 0.1 ohm shunt power resistor. It is from OPA541 datasheet. It limits short circuit current. 0.1 ohm gives us 5A limit. This limits my output power, but I still have enough power for music. The shunt must dissipate about 2W of thermal power. Just place 000 resistor on it and enjoy full power and risk of short circuit.

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One Response to HiFi audio amplifier using Burr-Brown op amp

  1. hifiturk says:

    good article

    thank you

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