My first GC finished

[iceman]

Hello !

I now finished my first GainClone(LM3875), and i sounds great.
I post some pictures later.(or tomorrow)
The schematics i used was this one from "Ukram"

http://hepso.dna.fi/misc/LM3875/LM3875_amplifier.html

 

[iceman]

pictures

Okey, not the best quality.
Here are 1 picture of my Gainclone.
The heatsink is from an old Pentium II

 

[Nuuk]

Hi Iceman and well done with your first GC. Have you done a stereo pair yet or just one channel?

BTW - bad luck about your car this afternoon! 😉

 

[iceman]

Hi !
I dont want to make both channels if it's sounds terrible.
But it sounds great so the second channel coming soon.

 

[Nlights]

Heatsink

Is the heatsink big enough for the lm3875 ( how hot does it get? ), I was thinking of using a P4 heatsink for my gainclone, since I can't really find anything else that is suitable and doesn't cost a fortune where I live.

 

[iceman]

Hi

I hope it is, because thats all i got.
I've playing with low volume(probably between 1-2½ Watt) for about 1½ hour, and I could easily
put my finger on the IC. What happens when i turn the volume up? I dont know.

 

[iceman]

Hi again

I forgot:

My HTPC Celeron 1700 runs whitout fan & heatsink.
And the 1700 produce 19 Watt at full load.

 

[Nuuk]

Is the heatsink big enough for the lm3875 ( how hot does it get? ),

This is one of those 'how long is a piece of string' questions 😉

It depends on the rail voltage that you drive it with and how loud you listen.

If you keep the rail voltages around 26-27V (18-0-18 transformer) and don't go stupid with the volume, a PC heatsink should do the job (for one chip).

They are certainly cheap enough to try and if they do get too hot, you could try adding a thicker piece of aluminium bar.

 

[iceman]

I use a 18-0-18 V transformer(25.2 V) and i dont use it to play for my neighbours.
If it's break dosent matter because it so cheap.
Total cost for my mono Gainclone exkl board and transformer is
about 16€
I got the LM3875 as free samples from National.

 

[ukram]

All right! So now i can say it works 🙂 The coil looks too simple to me, but i guess it is not very important...

 

[iceman]

Hi

Yes!, you can say it's work.
About the coil, i dont use any coil at this moment.
I gonna put a coil there in the end of the week.