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Hi all,
I'm new here. I'm a guitarist/pedal steel guitarist trying to service my own tube amps with not much technical know-how.
I copied a 6G16 Vibtroverb circuit using the same values shown in the original Fender layout. With the specified 33K resistor in the bias supply, the reading on the 6L6 power tubes is only about 19 mA. I've been trying lower value resistors in place of the 33K to bring that reading up because I don't much like the way the amp sounds. Last value I tried is about 24K, which brings the mA reading up to 23 BUT I get an immediate shrill howling out of the speaker when I turn on the amp - this is with the intensity knob at >0. Any ideas what I might be doing wrong? I tried wiring in a bias adjustment looking at the Weber 6G16 kit layout(https://taweber.powweb.com/store/6g16_layout.jpg), trying both a 10K pot and 50K pot with the same results: Hoooowwwllll.
Any advice would be greatly appreciated!
Dan
I'm new here. I'm a guitarist/pedal steel guitarist trying to service my own tube amps with not much technical know-how.
I copied a 6G16 Vibtroverb circuit using the same values shown in the original Fender layout. With the specified 33K resistor in the bias supply, the reading on the 6L6 power tubes is only about 19 mA. I've been trying lower value resistors in place of the 33K to bring that reading up because I don't much like the way the amp sounds. Last value I tried is about 24K, which brings the mA reading up to 23 BUT I get an immediate shrill howling out of the speaker when I turn on the amp - this is with the intensity knob at >0. Any ideas what I might be doing wrong? I tried wiring in a bias adjustment looking at the Weber 6G16 kit layout(https://taweber.powweb.com/store/6g16_layout.jpg), trying both a 10K pot and 50K pot with the same results: Hoooowwwllll.
Any advice would be greatly appreciated!
Dan