My car audio amplifier

[J.Carlos]

Hi!

This is my first car audio amplifier prototype, it's based on the TL598 pwm controller and the OPA549 power op-amp, supply rails run at +/- 29V (regulated), the heatsink/chassis can't disipate the heat for long periods at rms-power tests, but the amplifier can deliver 75Wrms@4ohms for a short time.

The pictures are very bad, but at least shows the amplifier

[TO-3]

Looks good. Do you have a lid? I'd put a fan on it and use forced-air cooling. Maybe that will help.

[DJNUBZ]

That looks great!!! I second the fan idea. Use a small fan and underpower it so it is quieter. You could even use two in a puch pull configuration.

How does it sound?

[Paradise_Ice]

It is very beautiful and simple as it should be.

If you can make a amplifier to give 800watts rms at 4 ohms i will buy it

[DJNUBZ]

If he could get 80wrms a chan. and make it sound great I would love to try to build something like this.

[J.Carlos]

In a few days I will reply in more detail, sorry, this days I can't.


Greetings from México.

Juan Carlos

[TO-3]

I should have seen this before. Do you have hold-down bars for your power devices? You probably won't even need a fan(o dos) if you can press those bad boys to the sink.

[J.Carlos]

this days I can't

Sorry, I meant “these days”


Yes, I have a lid for the amplifier (and better pictures):




The lid assembly isn’t finished yet, that’s the reason why you don’t see any screws .

A fan isn’t considered because at normal listening tests (music) the amplifier doesn’t get too hot .


How does it sound?, mmm, I can only say that sounds good to me, you’ll see I don’t have much listening experience with “reference equipment”, also as you can read, my english is not good (not as good as I wish) so, I have a lot of ideas that I don’t know how to translate properly (I’m working on it but any help will be welcome).


I do have bars to press the power devices (the pictures in the first post shows an unfinished interior)



The bad news:

The supply was not stable (at 1Khz and producing 75Wrms@4 ohms on a single channel it was), I did the feedback compensation wrong (anyway it is only a prototype so it worked for that purpose) and burnt the mosfets twice (one time at continuous power test, trying to get the same 75Wrms@4ohms but this time at 20Hz and the other at full music power test with both channels driven), so a new design is coming soon.


Juan Carlos

[maylar]

Very nice. What did you use for a fuse socket?

[J.Carlos]

I took the fuse socket idea from an old sony amplifier.

With a couple of faston connectors like these:




I removed the plastic cover, soldered a pair of wires (as indicated in the next picture) and bended the part "a" and the wires so I could solder the connectors in a through hole fashion.




That way, the socket (or better said each connector) is fixed firmly to the pcb