Chip Amp Photo Gallery

[Mike-Toronto]

VLSI, if you have not found another resource on X-Y caps look here:
http://www.justradios.com/safetytips.html
When I restore old radios I add a 3 wire cord and a X-Y cap.

Great link!

 

[fishski13]

simple Gainclone

a simple Gainclone i built for a good friend.

-LM3875 chips soldered P2P with terminal strips and the PS on Vectorbord.
-schematic is per Peter Daniel's of Audiosector.com, with obvious aesthetic influence from PD as well.
-chassis is DIY with sanded aluminum and tung oiled cherry wood.

http://i23.photobucket.com/albums/b353/fishski13/LancesHi-Fi001.jpg
http://i23.photobucket.com/albums/b353/fishski13/015.jpg
http://i23.photobucket.com/albums/b353/fishski13/017-1.jpg
http://i23.photobucket.com/albums/b353/fishski13/LancesHi-Fi020.jpg
http://i23.photobucket.com/albums/b353/fishski13/LancesHi-Fi002.jpg

 

[VLSI]

DynacoDave & Mike-Toronto

Thanks for the excellent link.
I worked contract for a loss adjuster some years back and have seen some nasty fires started by Loudspeakers (twice) CRT monitors and TV's (too many) clock radio, electric blanket, ceiling fan. the list goes on.
DC protection is a must for direct coupled amplifiers and try where possible to use transformers with internal thermal fuses, also despite some commercial manufactures not earthing equipment, Good earthing is a must for all DIY projects!
I have built 10+ chip amps and all but one (no longer used) have DC speaker protection.

Regards Greg

 

[jinx]

this is my masterpiece.
i'm just waiting for another transformator, but then it's finished.


http://666kb.com/i/b9dav51pyhae3fhfd.jpg

http://666kb.com/i/b9davvy8fkmwflp15.jpg

http://666kb.com/i/b9dawdm4j5q4n2lmh.jpg

http://666kb.com/i/b9dawmyyt5t9ww0zd.jpg

 

[FastEddy]

fishski13: Very nice ...

jinx: Slow loading images, but well worth the weight ...

I love this thread

 

[Banfi T.]

First attempt to build a minimized Gainclone. I had a relatively small box (30cm x 20cm x 6cm), but I wanted to do a dual mono configuration, so I did.

I am not happy with the internal wiring, I will redo later the circuit probably. Nevertheless, the amplifier works, has almost no noise. (a big suprise for me, seeing how close the transformators are.

 

[Banfi T.]

And a picture a took last night

 

[Alchamist]

hi,

This is my chipamp.Buffer designer pedja rogic you know and the regulator and general amplifier designer dxvideo.thanks for dxvideo's helps...

 

[Alchamist]

Other photo..

 

[Alchamist]

The bias current rate is 6mA..

 

[madqwerty]

My MAGIC !

here it is my LM3886 GC,
it was made following a free project created and posted by an expert DIYer on the italian T-Forum..

hi-res internal connections :

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

low-res external pics ( i love recycling used and ugly cases ) :



details on the safety-earth star, completely connected to every external metallic part of the case (also the power switch case) but TOTALLY DISCONNECTED from the electric ground star (0v) because of ground loop noisy issues (or something similar )

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

can you see any electric SAFETY issue ?
thanks,
marco

 

[Ted205]

is the star ground floating ?

 

[madqwerty]

is the star ground floating ?

Hi Ted,
sorry for my poor comprehension (both in english than in tech.issues)
what do you mean with "floating" ?

the ground star connects the grounds from the two P.S. boards, the grounds from the two amp.boards, and the ground coming from the inputs and the outputs tied together, nothing more,
in this way it's floating form the safety earth
(in my last pics, ground star is above the safety-earth star, because they started to be connected, but i experienced the noisy issues, resolved by separating earths from grounds..)

p.s. i will soon try to reconnect them, because i've a new suspect for the cause of the noisy issue (a TV set, connected by SCART cable to my dvx player, which is connected by a passive pre-amp to this amp)

thank you
marco

 

[madqwerty]

sorry for the new post, i'm under moderation (new user) and i can't modify the above post..
i know that it would be better to connect grounds with safety earth by using one (better two) groud loop breakers (i've read this thread )
My need is knowing if my present configuration can be dangerous.. remember that my safety-earth-star connects every external metallic part to the earth pin of the IEC device, in which i connect line, neutral and earth coming from the wall plug..
tnx!

 

[AndrewT]

My need is knowing if my present configuration can be dangerous.. remember that my safety-earth-star connects every external metallic part to the earth pin of the IEC device, in which i connect line, neutral and earth coming from the wall plug..

all exposed conductive parts must be permanently connected to Safety Earth.

This includes the far end of the speaker cables and the far end of the interconnects.

From your description it appears your chassis is connected to Safety Earth, but that the speaker return lead and input socket ground connections are only connected to the Audio Ground.

This is potentially very dangerous.

 

[madqwerty]

thanks Andrew..

 

[CECCO]

Here's my new creation.
ciao.

 

[CECCO]

Front

 

[CECCO]

overview

 

[CECCO]

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