300 watt Hi-fi power amp project.

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Just to update that I got the PCB made in double layered, with provision to mount the power transistors on board.
This will eliminate the hassle of hard wiring the trannies and make it less prone to joint failures which i was experiencing in earlier builds.

Top side:
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Bottom side:
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These are the earlier version PCBs:
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I got a nice enclosure for my PWA300 amp. This is from Soundfoundations.
I used DIY enclosures in my earlier builds and was not really happy as they never did justice to the amps.

I am quite surprised at the quality of the chassis, simply amazing and top class. It looks stunning with decent fit and finish, actually better than the images posted by Ali.

Now with the V2, the new enclosure will surely complement the build.

Bomb proof packing:
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With feet, IEC socket, power switch and screws for mounting:
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Huge real estate inside:

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...
 
Just to update that I got the PCB made in double layered, with provision to mount the power transistors on board.
This will eliminate the hassle of hard wiring the trannies and make it less prone to joint failures which i was experiencing in earlier builds.

Top side:
View attachment 55473

Bottom side:
View attachment 55474

View attachment 55475


These are the earlier version PCBs:
View attachment 55470

View attachment 55471

...
Hi Sir,

Any extra PCB's available ?
 
Nice and sturdy looking cabinet @hydrovac

I see a rectangular recess on front panel. What is that for?
There is also a label included in the hardware...
1617693827379.jpeg

Hi Sir,

Any extra PCB's available ?
Suman, first i neeed to build the dual layer PCBs for evaluation and then order for more boards... BTW i have couple of earlier version PCBs if you are interested.

1617694215036.png

...
 
Just to update that I got the PCB made in double layered, with provision to mount the power transistors on board.
This will eliminate the hassle of hard wiring the trannies and make it less prone to joint failures which i was experiencing in earlier builds.

Top side:
View attachment 55473

Bottom side:
View attachment 55474

View attachment 55475


These are the earlier version PCBs:
View attachment 55470

View attachment 55471

...

Started populating the boards...

1631361113441.jpeg

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...
 
The PCB work was on hold for a while, as i was waiting for some components. Recd them today.

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Made a simple Transistor hFE test jig based on this circuit for matching pairs. Currently measuring NPN transistors (BD139 and BC547)... need to build the other half for PNP though. Will resume populating the boards once i measure all the transistors.
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...
 
Nice to see a high power amp project on the forum.
Wow, i love those metal can trannies.......... :D
Nice to see after all these years ...
Searching for few more components i came across and ordered this hFE tester...
View attachment 62128
Back in the 90's I used the SANWA transistor tester meter ST80 to measure hfe and test bjt's and power mosfets.

In the 90's Elektor published the 300W power Amplifier. Very similar to this . Here is the link to that .... https://alectronicx.blogspot.com/2014/12/300-watt-power-amplifier-elektor-111995.html?m=1
 

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Last edited by a moderator:
Little more progress... got 50x50 Aluminium angle and cut to lengfh, mounted power transistors... satisfactory assembly.
 

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