Hello,
Please help me, I have assembled K8020 tube preamplifier.
It worked for about 1 month without any problem.
The sound was great, functionality agreed with documentation.
And yesterday an RCD in my electrical installation switched off during playing music trough K8020.
I checked the preamplifier, and the AC fuse (250mA) was burned.
I have disasembled the kit and checked for the simple shortcuts or damaged elements.
But there wasn’t any burned ones, any capacitors without any sign of overload etc…
So I decided to try to run it once again.
And the small 250mA fuse burned again.
Please, help me, what should I check first, could it be that the transformer is damaged?
I’m from Poland with 230VAC and B+C points are joined.
My first plan is to disconnect steering of RY9 by unsoldering T10 transistor. Eventually unsolder diodes D16 and D19.
And than I will try to power it up with AC.
This will show if the tranformer is a cause of the problem or not…
What do You think?
Maybe You have any common problems like that and there is a usual cause of that problem?
Best regards and waiting for info.
Lukasz Posuniak