How to test output watts?

[Edwin Dorre]

Edwin,

your bias was at normal level! I think if you would try a few different transistors for the current source you would see changes in bias too.
The current trough the transistor + Vbe defines the working point.

william

Changing to the 523ohm resistor for a other current gain upped the power to 100W and to 67W in 5 ohm. However I also changed the R26 to 240K to up the bias a bit, so I have now about 112W in 8 ohm and 81W in 5 ohm...

I am happy now! I needed a bit more juice in the 4 ohm department as I own B&W Nautilus 802 which drop a bit towards 4 ohm ...

Now I have to build the lot in a case, as all is build on a MDF board.

Edwin

 

[jackinnj]

Edwin's Spark - and blown cap

A spark is nothing, the cap below went off like a shotgun shell -- it was from the bias circuitry of a photomultiplier HV supply -- I ran too much current through it.