Dedicated 20 amp lines/should i use a sub panel

@noromance,

From the picture of one of your mono amps you are not using the green safety equipment ground wire. I assume both amps are wired that way.
https://systems.audiogon.com/systems/1593#&gid=1&pid=11

How about the preamp, are you using the safety equipment ground on it?

I also noticed the steel cover plate on the single receptacle outlet.
https://systems.audiogon.com/systems/1593#&gid=1&pid=14
Not that it would cause the hum issue, it could have an effect on the SQ. Just for the heck of it pull the steel cover off the outlet and see if you can hear a difference. If yes just install a nylon plate in its’ place.

By the way, nice looking vintage equipment.


Just an added note.
I ran two 10-2 with ground NM-B cables, (Romex is a Trade Name manufacture of NM-B sheathed cable), around 75ft each in length. Preamp and amp are tube. System is dead quiet. Ear right up next to the drivers of each speaker.


Jim

Jim,
Thanks. Correct - that’s how I received it from the seller. Not sure if Stu R. originally did that or if it was the seller. As the REL is fine and grounded, the hum loop may be from the monos. I dunno. The Croft preamp has the safety ground intact as factory supplied. The 401 is also grounded. Interesting notes on the steel plate. However, I’ll definitely try it on the DIY 4 duplex receptacle unit if I can buy one in that size. Thanks for your help and apologies to the OP for going a little off-topic.

Thanks everyone, i appreciate the info. i guess ill forget about the sub panel as it seems like there is little to no benefit by adding it since the 3 runs will all be under 50 feet and i'm not going with an Equi=Tech as much as i would love too.

noromance,
No apology necessary, i'm enjoying all the different opinion's and just absorbing all the info.
   

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