80W @ 6 ohm

[Anarion]

Hi there, I'm new here. I want to make myself an amplifier with the LM3886(TF), the thing is that i own a pair of loud-speakers (Aiwa SK-810) from an old stereo.
I was wondering should i make any kind of modification to get 80W @ 6 ohm?
Or what is the max power i could get from this chip??
What PSU should I use?



Well, that is the first thing i wanted to discuss. The second is that I was willing to do some kind of "logic" input so i could use de switch "mute" to toggle it from the computer. I want to use something really simple like a PAL or a GAL, i know how to make it work in paper, but i don't know how to program them! Any help here??

Thanks in advance to you all.


Anarion

[Dxvideo]

Dear Anarion,

You can get ~83W into 6R load with LM3886T.. You'll need 2°C/W heatsinks for each chip. The power supply must be 35v symmetrical (35+35) at least. And the current need is 5.25A for each rail. That means you will use 26+26 v secondary 275VA transformer, seperated rectifier bridges and 20,000uF reservoir capacitors for each rail.
And if u use Rf=20K, Ri=680R then your input sensivity will be ~1v RMS for 83W output...

PS: With LM3886TF you must use 1°C/W heatsink which is really big one. And even with this heatsink, chip will be still very hot!

[Puffin]

Why do you need 80 Watts ?

[tangmonster]

Because people base wattage on commercial amplifier ratings with pathetic power supply's and pmpo or MAX power ratings.

[Puffin]

I don't understand your answer. Do your Aiwa speakers handle 80 watts continuously ? Do you want to go deaf ?

[tangmonster]

i Didn't really give an answer, I just think that most people have a misunderstanding about RMS wattage and loudness , based on market related wattage ratings of commercial amplifiers.

[Corax]

Concerning PALs and GALs I can give you support. If you're looking for programming them you need to look for a "PAL/GAL programmer" (i.e. google for it). Many (E)EPROM programmer are also capable of burning those devices. So watch out what they are able to program and what not.

In addition to the hardware you need a PAL/GAL assembler to get the JEDEC-file which a programmer definately needs to program the device successful.

For a burner hardware you might try this one: http://elm-chan.org/works/pgal/report_e.html

For the PAL/GAL assembler running under windows I have no clue since I got my ATARI ST/TT/Falcon for that purpose with a special build hardware and a matching assembler.

Good luck.

[Anarion]

Originally posted by Puffin
Why do you need 80 Watts ?

I don't know, i didn't know it was going to be so hard. Do you think that using this loudspeakers with the normal config would be good enough?

[Anarion]

This are REAL 80W loud Speakers you should see the amplifier and the PSU from the stereo i have.

[Anarion]

ooohhh, i see, sorry i thought that using a 56W or what ever wouldn't be enough to "move" the speaker and then the sound was going to be "estrange".
Then, i'll just go for an 56W amplifier