AC mains dress

[Randall]

What are the effects of running AC mains parallel to the chassis? My DRRI had the power cord coming over to the switch and fuse on a big raised arc. I "fixed" this by running both hot and neutral along the bottom crease to the switch/fuse, and then back again via same path before taking a right turn to the PT. Since this amp now has a low level hum I can't find, I wonder if this method can induce unwanted current in the chassis, causing hum? And maybe the big incoming lines arc wasn't laziness, but for a reason?

[Tom Phillips]

...maybe the big incoming lines arc wasn't laziness, but for a reason?

I'd say that the original wiring was just hurried messiness. Your description of reworked wiring sounds better and dressing the wires close to the chassis should not induce hum. Good practice would be to tightly twist the wires together but, even if you didn't twist them, I wouldn't expect it to cause a problem in a DRRI.

[Randall]

They are twisted, and neatly run. So much for that hope!

[Tom Phillips]

One more thought - Don't route the line power wires close / parallel to the wires connecting the phase inverter to the power tube grid pins. Same caution for the screen wires even though they will be less sensitive. This is probably not the cause of your hum but it's worth keeping in mind.

[Randall]

Thank you. Not the case, but duly noted.

[Steve Conner]

AC mains dress sounds like something Lou Reed might have worn on the Transformer tour.

[g1]

AC mains dress sounds like something Lou Reed might have worn on the Transformer tour.

Yah, what's up with all the fashion threads lately, there was another one just recently about "soldering station wear" .