Newbie 7 channel Gainclone complete

[sachi]

Hey all,

I am glad to report that i have finally finished my gainclone projkect customised for my 3 way active speakers.

Taken me 9 months to finish this.

In fact this is a
DIY 7 channel Gainclone amplifier/Active crossover/Passive Preamp

The components in the different stages are...
------------------------------------
Passive Pre Stage
ALPS RK-27 Pot(10 k log Dual Gang)
Phillips Log pot(Center cahnnel)

Active Crossover Stage(From Silicon CHip)
OPA4228 based 4th order Linkwitz Riley

Amplifier Stage
[ Highs - 50watts@8ohms ]-LM3886(Bran GT's board)
[ Mids - 60watts@8ohms ]-LM4780 Parallel mode(Peter's Board)
[ Lows - 140watts@8ohms ]-LM4780 Bridged mode(Arasu's Board)
[ Center channel - 60watts@8 ohms]-OPA541


Thanks to everyone who heped me realise this project...specially Nappylady, Arasuk and Peter Daniel.

Thanks to Arasuk for helping me out and see the project to its completion.

 

[sachi]

Fins..

 

[neutron7]

congrats! thats a pretyy ambitions "newb" project!

lets have some pics of the insides then

 

[sachi]

Another pic

 

[sachi]

Desperately need some new Aluminium knobs

 

[sachi]

With my Active 3 Ways...am a noob to speaker designing too


gonna put it in my listening room once i com back ...leaving to Mysore in an hour..will be back only next weekend.
Active 3 way speaker
--------------
Vifa D27TG-35 (Tweeter)

Scan SPeak 13M/8640(Mids)

Dayton 10 inch Classic(woofer)

 

[sachi]

Will post the details of the amp when i come back....as u can see..grill cloth is left over..will put thoseon soon..


Thanks guys...DIYaudio.com is great...
Cheers

Sachi

 

[sachi]

congrats! thats a pretyy ambitions "newb" project!

lets have some pics of the insides then

Thanks Neutron...will post pics of the insides when i return from Mysore next weekend.

 

[Leolabs]

 

[recca]

Nice!

Great project and something I'd like to try later too! How are you controlling volume on all six channels with only one pot?

 

[venki]

sachi,

Great work.

By the way from where did you get the Dayton (I mean is it available in India?).

 

[demogorgon]

great stuff

would be great to have the will to actually get my 6 channel amp done.

 

[sachi]

sachi,

Great work.

By the way from where did you get the Dayton (I mean is it available in India?).

Thanks Venki.
The Dayton was procured through my friend. He got it down(alogwith the Scan Speaks and the Vifas) from the States.

great stuff

would be great to have the will to actually get my 6 channel amp done.

Thanks Demorgorgon..

 

[sachi]

Nice!

Great project and something I'd like to try later too! How are you controlling volume on all six channels with only one pot?

Thanks Recca.
Thanks Leolabs..

Recca i am using the pot in the folloowing manner.

Input RCA-> 2 pole 6 way input selector->POT-> Input of active crossover->output of crossovers->input of amplifiers .
Thus all the six channels are controlled thouigh in essence i am controlling only the eft and right channels.
i can however control each of the drivers from the crossover board using the trimmer pots.

 

[sachi]

congrats! thats a pretyy ambitions "newb" project!

lets have some pics of the insides then

As promised...here are the pics of the inside...bear in mind that there are two passive crossovers, 3 transformers, 7 amplifier modules, input selector, and a 3 way stereo active crossover in this one case and me being a noob i kinda feel that its a pretty good job of wiring.

Am sure my future amps would be better laid out..

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

Crossover--

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

 

[sachi]

I Blew One of the channels

Hey guys, if u can see in the pic of the amp overview u can make out that one of the channels has been removed from the heatsink.

Well, while i was playing my amp last night i guess taht the temp increased beyond safe limits and i seem to have blown one of the chips(Peter's Lm4780 board) the chip was wired in parallel..
I always seemed to have some problem with this config..will be replacing both the paralleled boards with Arasu's Bridged boards and will use LM4732 ..

Will make the modifications in a couple of weeks.

I have to thank Arasu for insisting that i put capacitors in series with the tweeters and mids to protect them from DC else my brand new Scan Speaks owuld hev been left speechless.

here is a pic detailing the paralleled Board....u can see how it has blackened.

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