Leach Super Amp Pcb Re-Design (LSAPRD)

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I read an newspaper when i was in Denmark, looked like Dutch to me.
OK, it was in a bar, and there was a nice Danish girl sitting beside me, but i could not understand a word she was saying.

Maybe that is why so many Dutch spend their holiday in Denmark ?

Or is the weather, the beauty, or the fresh air in Denmark.
Me, i like the food and beer.
 
jacco vermeulen said:
I read an newspaper when i was in Denmark, looked like Dutch to me.
OK, it was in a bar, and there was a nice Danish girl sitting beside me, but i could not understand a word she was saying.

Maybe that is why so many Dutch spend their holiday in Denmark ?

Or is the weather, the beauty, or the fresh air in Denmark.
Me, i like the food and beer.

Hey Jacco, this is the Leach thread and not the Letch thread! :)

I like a little Danish in the mornings myself now and then. :)

Regards

Anthony
 
After waiting a couple of days and nobody adds to this thread i suppose that asking Jens if he is willing to convert the Extended Leach board he did to just the front part with a jumper connection for the output boards should please all.

> With solderpads for attaching powerlines from active
regulator boards to the Leach front end pcb or just regular
powerlines.
> An output board for 6(?) TO247's.
> An output board for the 2(?) double barrels.
> All three boards with jumper connections for
signal in/out/power/ground/feedback.

So far i have not read a posting disagreeing with some of the Extended Leach's features, other than the possibility of a smaller pcb and smaller R's.
Me, i find the Extended Leach board Top of the Pops.
Just that one with connections for output boards that take either TO3's or TO247's would make me a very satisfied kid.

Does anyone know where i could find the datasheet for the Toshiba 2SA1302 and 2SC1381 ?
I should have them somewhere in my paper data dump, a search on the net so far ended up Zilch !
I have no experience with the MJL1302/MJL3281 so far, but would like to compare the datasheet of the MJL's with the one of the Toshiba's.
 
I could not keep waiting for a conclusion so it happens that I’m almost done with the small signal part of the super leach amp. The PCB is based on my extended design but without the output and driver transistors.

Should I just add solder pads to the power section, or should the connection be a “bridge” like my prototypes?

\Jens
 

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Jacco wrote:
I was wondering who are still in favor of a front stage pcb and two power boards ?

I am in for 4 Leach amps:
> With solderpads for attaching powerlines from active
regulator boards to the Leach front end pcb or just regular
powerlines.
> An output board for 6(8) TO247's.
> All three boards with jumper connections for
signal in/out/power/ground/feedback.
Thanks, Loek
 
Pcb

Hello all , I like the idea of seperate boards too. Would nice to use some kind of connector or even terminal posts to jumper boards together but what ever is easiest for jans .I would like two sets also when there is a wiki . Oh where do we find these wiki's and do they taste like kiwi fruits ? is there a parts list for your extended board.I cant open those zip files you have my pcad is too old. Would your extended version make a good subwoofer only channel .
 
Size does matter

Hey , That sounds good to me .Its about the same as the one I drew Up for the low tim but never finished connecting the traces.I should be able to use the enclosure I just got , What size xformer will we need. I got an 800va 40 x 40 . How Big is the output board gonna be . I mean as far number of transistors.
 
Parts

oh Never mind on the parts , I rechecked the delta and its already in pdf.The zip folder I had with gerbers and stuff I must have got somewhere else , I really need to stop downloading every thing I see , I did get hard drive 40 % fragged up though , and thats got to be a record well at least for me . I think I need to clean some stuff up . Jens love your work cant wait for the boards to come out , I should be home by then with my workbench and tools , I do miss them so much .
 
JensRasmussen said:
Update,

The small signal PCB for the superamp looks like it will be about 11 x 13 cm = 4,3 x 5.2 inches

Is this ok?

\Jens


Forgive me if this is a stupid question. If you are going to do separate boards, what is the advantage of redoing the signal board? Is there something wrong with the one that Dr. Leach designed? I thought this thread was about creating a board to accommodate flat-pack output transistors. If we are going with separate boards, wouldn't we only need the boards for the outputs?

Thanks, Terry
 
Hi Terry,

Good point, but I have not been able to get the original parts so I have been using MJL340/350 in the VAS and predriver stage.

I like to have everything on one board, but this solution seems to unpopular.....

Anyways, you might be able to use an output board along with the original boards if you want to.

I think the one board solution is better, since the long wires are eliminated. It does however need a bigger heatsink

\Jens
 
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