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Power suppy mods

post #1 of 8
Thread Starter 
OK, my previous LM317 crapped out, basicly it decided not to regulate at all. I had a 7812 sitting around and I'm too lazy to go to rad. shack. While I was at it I decided to make some improvements to my amp. Here's what I did.

Raised decoupling capacitance from .2uF to 1186.2uF (added 650/535uF elect. and 1uF metl. filt)
Raised gain from 5.5 to 8.7 (needed a little boost)
Changed regulator

I was worried at first that sound quality would be damaged by the regulator change, at the 7812 is only rated at 60dB ripple rejection, compared to 80dB for the LM317.

I didn't have to worry. The amp now sounds amazingly more powerful and a good bit of static is gone. I can turn the volume all the way up and hear little more than a faint hum.

As for sound quality I can't believe the difference, bass is very tight and controled (loud notes don't die as they did before) and the treble makes me wince, gotta love the V6's. The extra gain helped too, now I can keep the volume control lower where it seems to be more sensitive.

It isn't all positive though. The 7812 is bringing 22V down to 12V, and therefore produces gobs of heat. Also I now have a 1 1/2in long welt on my leg where solder dripped onto it. The one time I don't where pants and I drip solder...grrrr.

Overall, I'm happy with the results (except the part about burning myself). When I get a larger heatsink everything should be dandy.
post #2 of 8
How much solder were you using at a time? My welt-on-leg-from-dripped-solder is only about half a centimeter.
post #3 of 8
Thread Starter 
I had just tinned the tip and was moving to clean it on a sponge. It was loaded.
post #4 of 8
You weren't wearing pants? Hey man, you're lucky it was your leg you burned!
post #5 of 8
Thread Starter 
No, I don't solder naked. Had on shorts.
post #6 of 8
post #7 of 8
Originally posted by CaptBubba
No, I don't solder naked. Had on shorts.
You don't know what you're missing!

I'm reminded of the old bumber stickers "Surf Naked" from the 80s. I've got a new one now "Solder Naked".
post #8 of 8

This has very little to do with types of regulator you use. I think the changes in sound quality is caused by you using larger capacitive reserviors. This makes transients nicer.

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