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I just hooked up my sub to one of my 3886 amps and it played it perfectly!!!

But now, I have two transformers that I would really like to use so that I can connect two more amos to it. The one is a 20-0-20 3.2 A per secondary winding. Will I be able to use this one to power the amps just like the origianl 160VA I used? Because I remember that you said earlier that the voltage would be too high for the amp to handle, but what if I get some way to lower the voltage? The other transformer is a 30-0-30 5A per secondary transformer. What would you suggest I do?

Thanks!!!

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I just hooked up my sub to one of my 3886 amps and it played it perfectly!!!

Maybe you didn't drive it higher than 68W into 4 ohms. You don't have a circuit to limit its output power, so it might exceed 68W then its SPiKe protection circuit will become active. They say that the protection circuit really messes up the sound and it sounds horrible.

I have two transformers ... one is a 20-0-20 3.2 A per secondary winding

It will be fine with a single LM3886 IC, a 4 ohm speaker will receive about 64W and the transformer will not be overloaded.

The other transformer is a 30-0-30 5A per secondary

The voltage is too high for the LM3886. A different amp that uses it will provide about 170W to a 4 ohm speaker.

Have a look at the amp circuits at www.ampslab.com/projects.htm .
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Without the zobel network, the amplifier might oscillate and blow your tweeter. It will be noisy if it is oscillating, and maybe is getting hot.

If the noise is a high frequency hiss, and it reduces when the volume control is turned down, then the noise comes from the source that feeds the amp.

I don't think you posted the schematic you are using. The datasheet for the LM3886 has 3 different schematics.

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  • 2 weeks later...

Hi guys! Sorry for the silence. Had a lot to do! I finally finished my amps and speakers. Just need to finish off my speakers. As soon as I'm done i'll post photos. The sound quality is phenomenal!!!! I would really recommend if anyone wants to build a cheap, good quality amp the lm3886TF is the best!

Thanks for all your inputs! I really appreciated it! Now, onto the next project :)

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