Hybrid+ From Digilander doesn`t work

[ralf]

Perhaps anyone can help me:
I bought two hybrid+ from generoso cozza.

I build the supply for the heating, and the time delay and the ps for the PowerMosfets myself and they work.

When i switch on the hybrid+, the mosfets and the resistors in front are burning.

I dont know how to adjust, and find out where the problem lies.
The only thing Mr. Generoso tells to me is: "it must work".

I should say, that i have build several mos fet amps without problems.

Can anyone help me ?

thanks

Ralf

 

[timc]

Hi Ralf,

First I should say that I have not had any experience with this kit! I have read acouple of articles about it though.

I would start by checking the voltages in the valve section and adjusting the bias pot P1. If it is burning resistors when you turn it on, I would remove the mosfets, or at lease the grid stopper resistors.

You may not be particulary interested in this at the moment, but
http://www.tubecad.com has done a review on the circuit and proposed some enhancements. If nothing else it shows the voltages in the valve section more clearly (in particular try http://www.tubecad.com/march2001/page21.html).

Regards,
Tim.