Hi, I recently built a 5f1 clone and im having some weird issues with it. It worked fine and sounded good for the first month or so, until i decided to start tinkering with the nfb resistor. At once point, i decided to disconnect the 220k resistor that goes from the coupling cap to ground to get a better angle, and forgot to reconnect it. I then played through the amp for approximately a minute before the volune was suddenly halved and there was a burning smell. The 6v6 socket had been arcing from pin 2 to 3, and the tube was toast. When i realized my mistake, i put a new socket and tube in and reconnected the 220k resistor, but i am now getting some really bad, almost static-y distortion at high volumes. At lower volumes there is no distortion; it starts between 4 and 5 on the dial. Any ideas on what it could be? I know people say its usually the last thing to go, but could it be the ot due to the direct arcing from pin 2 to 3?
Thanks!
5f1 bad distortion
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JoshBernstein
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5f1 bad distortion
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Not really
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Stevem
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Kk
Measure you idle current on one of the outputs and then play thru the amp if you see the current go up a good amount and the volume is low and ratty then your OT is shorted on the primary and is toast!
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Stevem
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Lll
Also be sure that any traces of the arcing ( carbon track) from those two pins is gone!
I use a sharp metal scribe to get back down to bare plastic if the socket is not ciramic .
I use a sharp metal scribe to get back down to bare plastic if the socket is not ciramic .
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!
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!
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JoshBernstein
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- Location: Key Largo, FL USA
Re: 5f1 bad distortion
Will measure the current when i get home, but the arcing is totally gone, as replaced the socket.
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martin manning
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Re: 5f1 bad distortion
My guess is the OT is fried. If the output tube's grid is floating, the primary current will go sky-high and overheat the transformer.
Re: 5f1 bad distortion
Fitting a fuse to the B+ would be a beneficial mod.
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