Need advise on this amp...

[Tony]

Originally Posted by JojoD818

Just want to share a schematic of an amp I used to build. It uses cheap and locally available parts.

The book where it came from said that it can deliver 250W/8ohms and 500W/4ohms. I don't know if that is true because I have no way of measuring the power outputI have successfully built 2 stereo units and we use it for pa purposes. This amp may not be the clearest amp I've heard but it sure is loud! It requires a 35-0-35/25A transformer that is so huge and heavy (22Kg) that the locally available chassis needs reinforcements.

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Is there a simple/crude way for me to measure an amps power output? I saw a dummy load at a shop once, I can also borrow a signal injector and a digital voltmeter or whatever they call it. Can I measure an amps output power with these? How?

Jojo

wow, when i first saw the book it said 1000watts, this amp was copied from a TI audio book, originaly used TIP35C and TIP36C ouputs trannies if i am not mistaken.....

a lot of things are wrong with this amp....notice the 0.33ohm resistor at the collector of the output transistor instead of in the emitter? this is a dead giveaway that the author did not know what he was doing.....

the trimpot biasing is not a good way to implement, i have heard lots of report about failures in the field due to this....