Please, help me with Self Blameless

[Ric_rock]

Well, the new PCB!

I just reduce the space between components. However, the input capacitor (C1 - 1uF non eletrolitic) is very large and take some space in the board.

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

Thanks for helping. If someone herlp me with conexions, I´m pleased.

Ricks

 

[Mooly]

The driver transistors aren't normally mounted on the main heatsink... not quite sure how that will influence thermal stability. They should be on the main PCB with small individual heatsinks. Only the vbe multiplier is normally on the main heatsink. Ideally it should be in contact with one of the outputs... I used a TO92 outline fixed to the top of the TO3 outputs. Used a phosphour bronze "strap".
It should be OK though as you have it... just that there will be more thermal "lag" as it can't sense the temperature of the outputs "quickly".

I'll tell you something about the earthing if I find the link

 

[Mooly]

Have a read at all this, and look at the diagrams I drew...
http://www.diyaudio.com/forums/solid-state/101321-3-stage-lin-topology-nfb-tappings.html

 

[Mooly]

Caps are OK to use values you have. The 220 uf feedback return will be OK at 470uf... but may increase any switch on thump and will alter the low frequency roll off point (will be lower)
TR4 is OK but make sure it can withstand the full total supply. For -/+ 40 volt rails you need at least a 100 volt device. The originals were 2n5551 and 2n5401 for all except output and drivers.

 

[Ric_rock]

Hi, everybody

I´ve done another pcb. I´m tired so this will be the last version (althought I find a big error), because I´m tired to draw nem pcbs...

I expected this is correct!

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

Well, Thanks for helping.

Regards
Ricks

 

[Mooly]

Let us all know how you find the amp in use