Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dude on March 05, 2021, 06:04:59 pm
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I use to follow polarity when wiring filaments, same pins to the same pins, but I don't think it makes a difference. Whether you keep each pin 4 & 5 the same and all pin 9's the same, makes no difference...? Well, hopefully. I only have enough filament wiring in the same color to finish this amp I'm building. Finished the 6L6's and was just going to use the same color wire for the 12Ax7's pins 4/5 and 9, twist the wire and solder where she lands, 6.3V is 6.3 volts, not worrying about polarity, am I wrong here?
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What did Leo do?
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I think it makes no difference.
That said, I always wire all the 4/5 and the 9 pins the same. Call it what it is.
You know, if you use the same color wire to each, no-one will know the difference . . .
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You guys don't know :icon_biggrin:
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I think it makes no difference.
There probably is a difference. People smarter than I am say it makes for a lower noise level.
That said, I always wire all the 4/5 and the 9 pins the same. Call it what it is.
Same here. Less noise is better, generally, but thousands of Fender amps function just fine wired 'randomly'.
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... polarity when wiring filaments ... makes no difference...? ...
... People smarter than I am say it makes for a lower noise level. ...
I might not be any smarter than you.
But when I tried observing heater wiring polarity I heard no difference. That was around 1997, and I haven't bothered with it one way or another since.
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In the case of valves used in a balanced system, eg LTP, push-pull outputs, there’s a theoretical benefit in maintaining polarity. As this would help to make any induced hum a common mode signal, which would be rejected by the p-p differential amplification.
In reality, that theoretical benefit is of little value, eg single ended only amps don’t tend to have higher levels of hum from their heaters than p-p amps. Rather hum from HT ripple is an issue of far greater magnitude.
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It is beside the point, but I find it odd you ran out of wire at the stage of wiribg the filaments. Those are the first wires I put in after the power tx wiring...
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If you lay the filament wires against the chassis, they go in first. if you do the flying style (e.g. Fender), they go in last.