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I've got one of these newer Peaveys, 50W versions, with the "TPI" circuit and lights, that turn red for each tube when a tube fails, is pulling to little current, or too much current.
Owner brought amp in last month, saying after 30minute of playing, the lights would start to go red. I observed a pretty hot bias in the amp, and cooled it down, making the assumption that once the amp starting cooking at higher volumes, the current draw exceeded whatever window the TPI deems acceptable. LEft the amp on for 3 hrs and it was fine
Amp came back to me this week, he says same thing happening after 1 hr. Tubes are brand new. Also, he's operating this thing with the speaker defeated, and DI through the PA, on 2W mode.
Also now, the amp goes quiet when this happens. If you let cool off for 1min, it's fine, apparently.
I'm convinced there's nothing wrong with the amp, but some combination of the 2W mode, speaker defeat is tripping the TPI circuit.
DOes anyone have a schematic? All I can find is the original VK, with no adjustable bias, from what I hear, and no TPI circuit.
I'm thinking about just yanking the TPI circuit, but would like to see how it's implemented first.
Of interesting note is that the reason he likes this amp is b/c it has the DI out, so he can keep his guitarist(who uses the amp), at a reasonable volume!
Thanks!
Owner brought amp in last month, saying after 30minute of playing, the lights would start to go red. I observed a pretty hot bias in the amp, and cooled it down, making the assumption that once the amp starting cooking at higher volumes, the current draw exceeded whatever window the TPI deems acceptable. LEft the amp on for 3 hrs and it was fine
Amp came back to me this week, he says same thing happening after 1 hr. Tubes are brand new. Also, he's operating this thing with the speaker defeated, and DI through the PA, on 2W mode.
Also now, the amp goes quiet when this happens. If you let cool off for 1min, it's fine, apparently.
I'm convinced there's nothing wrong with the amp, but some combination of the 2W mode, speaker defeat is tripping the TPI circuit.
DOes anyone have a schematic? All I can find is the original VK, with no adjustable bias, from what I hear, and no TPI circuit.
I'm thinking about just yanking the TPI circuit, but would like to see how it's implemented first.
Of interesting note is that the reason he likes this amp is b/c it has the DI out, so he can keep his guitarist(who uses the amp), at a reasonable volume!
Thanks!
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