Hi I am trying to fix my beloved f3, one board is running around 20 degree Celsius hotter than the other 35 one side 55 the other with one particular resistor getting very hot, around 130c. I have checked ac at binding posts both sides 0. Not sure what to do, or how to bias or even if this would be of any use. I have very limited knowledge of electronics, the techs in my area have refused to look at it because it is diy, or they look and say they can’t fix it after charging $100. I don’t want to give up on this amp as it gives me so much pleasure, so any advice for dummy’s would be most appreciated the value of the resistor has not changed with the excess heat
regards roger
regards roger
Attachments
Last edited:
Do you have any equipment for diagnostics yourself or are you completely unable to test and fix even with guidance? Your picture doesn't show anything useful and the problem wouldn't be the side that's 55C. I would be more worried about the side at 35C. Is the amp actually non-functional on one or both channels and was it running properly until recently?
The best course of action would be to see if someone nearby would be willing to look at it for you but you don't have your location indicated. It's pretty clear who built the amp based on the blurry picture but it's just a guess.
The best course of action would be to see if someone nearby would be willing to look at it for you but you don't have your location indicated. It's pretty clear who built the amp based on the blurry picture but it's just a guess.
Hi
I am in north Fremantle Western Australia I know people don’t like the builder of the amplifier, but I was able to purchase this at a price I could afford and it has lasted over 10 years without any problems up until now. I am not sure what mr pass thinks about this, but I have seen people on this forum build and sell first watt clones for much more than I paid
regards and thanks for your help
I am in north Fremantle Western Australia I know people don’t like the builder of the amplifier, but I was able to purchase this at a price I could afford and it has lasted over 10 years without any problems up until now. I am not sure what mr pass thinks about this, but I have seen people on this forum build and sell first watt clones for much more than I paid
regards and thanks for your help
Take a deep breath and relax. Nobody is questioning when, why or how you came into possession of the amp and you'll possibly hear remarks about how unsafe this builder's amps are but that's not why you're here right? Let's go back and assess what degree of assistance you might need so I'll repeat:
Do you have any equipment for diagnostics yourself or are you completely unable to test and fix even with guidance?
If you have the ability to check voltages, post #1145 in the F3 Builder's thread has a schematic with test voltages shown at 5 different points to get started. From there you could pull the mosfets and test them and given the amp's age, you might replace all the caps on the boards with fresh ones as electrolytic caps dry with age.
F3 schematic
Hope things work out for you.
Cheers
Do you have any equipment for diagnostics yourself or are you completely unable to test and fix even with guidance?
If you have the ability to check voltages, post #1145 in the F3 Builder's thread has a schematic with test voltages shown at 5 different points to get started. From there you could pull the mosfets and test them and given the amp's age, you might replace all the caps on the boards with fresh ones as electrolytic caps dry with age.
F3 schematic
Hope things work out for you.
Cheers
Thanks for your reply
I only have a multimeter, I think the problem started when I bought a stereo coffee Ldr pre amp which is almost passive and is such a fantastic piece of equipment. I couldn’t get enough gain so I decided to change r1 to a smaller value resistor. I think I stuffed something up when replacing the boards.
I only have a multimeter, I think the problem started when I bought a stereo coffee Ldr pre amp which is almost passive and is such a fantastic piece of equipment. I couldn’t get enough gain so I decided to change r1 to a smaller value resistor. I think I stuffed something up when replacing the boards.