FIXED IT!!!!!!😀
New pot arrived today so I changed that and that fixed the last of the crackle. I kept getting an earth screech which I traced to old bad connections between the outer of the rca sockets to the power amp and the connector ring so I cleaned it up and soldered them together (crimped before) and that solved that. What I could not understand is tapping the amp changed the hum, what could it be??
I went over the amp again and again, then I saw it, one of the caps across the valves had come away from the board, I was quite excited to find something that had to be the problem!!
I soldered it back in place and connected it up. I waited and waited for the relay to throw in and the hum to start but nothing, then I realized the relay had thrown in and it was not humming!!!!
There is actually a tiny hum on one channel if you put your ear right up to the speaker, but the valves are very old some going white inside so my guess is the last tiny issue will be solved when the new valves arrive, fingers crossed and thanks everyone for your input.
Cheers
Chris
New pot arrived today so I changed that and that fixed the last of the crackle. I kept getting an earth screech which I traced to old bad connections between the outer of the rca sockets to the power amp and the connector ring so I cleaned it up and soldered them together (crimped before) and that solved that. What I could not understand is tapping the amp changed the hum, what could it be??
I went over the amp again and again, then I saw it, one of the caps across the valves had come away from the board, I was quite excited to find something that had to be the problem!!
I soldered it back in place and connected it up. I waited and waited for the relay to throw in and the hum to start but nothing, then I realized the relay had thrown in and it was not humming!!!!
There is actually a tiny hum on one channel if you put your ear right up to the speaker, but the valves are very old some going white inside so my guess is the last tiny issue will be solved when the new valves arrive, fingers crossed and thanks everyone for your input.
Cheers
Chris