mini-3886tf

[doggy]

Hello all;

Just wanted to display my 1st point to point wired amp.It was built because I had this transformer when rectified gave me +20-0-20 dc. This is the bottom of the voltage scale for this chip and it definitely works; has good volume.

Most likely about 20-25 watt/channel 8 ohm. With 10r accross the outputs and the inputs shorted I get 5.1,6.2 mv offset. The feedback resistor is 10k set by 428r to give a gain of about 24. The input caps are .47uf phillips[yellow caps]. I can say this is fun to do and it is playing "the nutcracker" as I type. Just using some old test speaks now.

The case itself is small; 8" long, 7" high,4.5" wide. The homemade stacked heatsink hardly gets warm at all; most likly due to the low power. This type of amp may be perfect for hi-eff. speakers.

will post an assembled pic later.

p.s. I want to give credit to Mick F.-his guide helped me a lot.

cheers
doggy

[inguz]

Nice!
Don't try carrying that thru an airport, now... ;-)

[doggy]

Thanks inguz, I really meant to build your amp but I sort of got side tracked and built this instead.But I can understand the satisfaction of trying something different; especially when you get lucky and it turned out better than could have been expected. This little amp belts out no lack of bass or dynamics. I am using a 95 db driver which is required with lower power. I boosted the capacitance to about 13,600 uf per side; it was all a tight fit, I had to measure all my available space. It's about the size of a kid's lunchbox. toal cost for this project was about $80. out of pocket.

listening to "grateful dead live"

cheers
doggy

[doggy]

another pic.

[inguz]

Hey - that's really nice looking casework!

[eLarson]

I like the green pilot light. Is it a biggish LED or a small lamp with a green lens cover? Or something else?

[Mick_F]

Thanks for the credit. Looks very good.

Mick

[doggy]

It is a green led. I picked this green-there are a few different shades available. What makes it is the led holder which has a cone shape face surrounding the led. I got these at the source-the old radio shack.-cheap.

cheers
doggy

[sagarverma]

very nice.
but mini

[doggy]

sagarverma:

I guess I should say "mini enclosure' by my standards. It's all in there, no outboard power supply. Also some caps were not of the compact type. most likely it could be smaller. This was difficult enough for me to do and I had to shift some parts around to make it all fit.

The bonus is: again, to me it sounds dam good; I can only compare it to what else I have around. I have been burning it in with 10r 10 w resistors. I do have a scope but not in use.

I polished the bronze with some brasso and sealed it with some furn. wax.

cheers
doggy