F5 Turbo Builders Thread

0.6V across 0.5ohm resistor is 1.2A pr device. With +/-32VDC that is 38W dissipation pr device, wich is a little high. The diodes starts to cunduct before 0.6V too. 0.3-0.4V to be on the safe side. if you want higher bias, you may want to lower the resistance of the source resistors.

I ended with 0.55V across 0.5 ohm resistors to get to the desired temperature on the heatsinks of my V2 monoblock. I like the sound a lot but you seem to tell that the diodes are always conducting? How can I check that?
 
I ended with 0.55V across 0.5 ohm resistors to get to the desired temperature on the heatsinks of my V2 monoblock. I like the sound a lot but you seem to tell that the diodes are always conducting? How can I check that?

there is no exact answer to what point they start conducting, as this is temperature related. you can meassure resistance over the source resistors. if its under 0.5ohm the diodes are conducting. But if the diodes are conducting the bias should fly thru the roof (i have not tried this in practice:D )
 
there is no exact answer to what point they start conducting, as this is temperature related. you can meassure resistance over the source resistors. if its under 0.5ohm the diodes are conducting. But if the diodes are conducting the bias should fly thru the roof (i have not tried this in practice:D )

Thanks. Is there a sound signature when the diodes are conducting?
 
Measure voltage across the Jfet source resistors and post value. Should be about 6-8mA when divinding that voltage by 10ohms. Measure Vgs of the N and P channel fets to give us an idea of where you are at currently. Also, tell us the voltage across the source resistors on the output fets so we can get an idea of what bias you are currently at. It is a simple solution and you must just go through it one step at a to pinpoint the problem. I don't haev the store boards so it might be nice to post a close up pic and schematic.
 
This is what I got from work. The JFet source resistors are the 10R ones?
zSVLLEM.jpg

deFIkWc.jpg

42XxOQr.jpg
 
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