This is my first amp build so I don't quit know what's wrong. I got the parts for a 5F1 champ clone separately (not in a kit) but got off brand transformers. All the voltages look good but everytime I turn the volume up, once I get past the midpoint on the knob the amp starts squealing very high pitched and I can hear the output transformer whine as well if I listen closely. I tried disconnecting the negative feedback loop but it doesn't change anything, I also tried swapping the cables on the primary of the output transformer but that didn't change anything either. So in the end I bought a Hammond version of the output transformer but that doesn't change anything. Anyway sorry for the novel :p anyone know what might be the root of the problem?
Is your wire from the input Jack to the grid sheilded and grounded on only one end?
Does flipping around the installed position of the coupling caps one at a time help the issue?
You also might try adding a 5 to 10k resistor right on pin 5 of the output tube!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Might be an issue with lead Dress... I know a few of my early amps had dress issues leading to squaking and squeeling.
The 5f1 is a pretty simple, low gain circuit, but as I can attest to, we DO make mistakes.... Double check your values, make sure your wiring is a short, clean and neat as possible, and take a pic or 2 so the guys here can do their best to help you.
I'm in the lead dress camp assuming it's wired correctly. You should pay close attention to the B+ layout in the output section. B+ too close to signal wires or output wires too close to the preamp section.
Electronic equipment is designed using facts and mathematics, not opinion and dogma.
Because you are a new builder, I'm going to guess some of our words don't mean anything. "Lead Dress" this means how you attached the wires and where they are placed, the shape and bends, and how close the wires are to each other and various components. Wire placement and installation can make a big difference. We call this "lead dress." No clothes involved!
