GHR Audio

5F6A bassman and 5E3 deluxe

Hello Lauri

One question :
On the schematics C20 shows 470uF 100V, but on the PCB is 47uF 100V. I have seen also a version of the same PCB with 47uF 250V.
Mine , after I changed from tube to diode rectifier PS, exploded. It should not be more than 60+V dc on the capacitor.. I am just wondering on others experiece . I am going to replace mine with a higher voltage than 100V for sure
Thank you

Voltage on the capacitor is about 1/8th of the B+ voltage. Even if the B+ voltage is 500V there should only be about 60V there. 100V capacitor should be enough. Do you have correct values for R37 and R38?

Hello Lauri
I checked R37 and R38 are correct values. But I noticed that R35 and R36 burned as well.. I think that is the source of the cap to explode.
They are supposed to be 100R according to the diagram... looks like lots of current went through...

Probably I have a clue of a possible problem:
I have added a DC bridge for V1 on the heater .
This has a ground connection , not sure where ... so I believe it should not be grounded in both sides (elevate heat circuit and DC bridge)....(according to the Wizard website)
What do you think? I could be in this case?
thanks

If you're using the same winding for DC and AC heaters then probably shorted the heater circuit with the DC bridge. You don't need DC for V1 heaters, just use AC.

Yes I suspected that... thank you Lauri