babadono

The most versatile is a "dummy plug". It will help troubleshoot equipment and interconnecting cables. https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf For quickness start about page 100.

Like this...How did you do this before?

That there is funny Ice skating in southern Mississippi Funny

Yea I don't think so....... Did anyone ever really believe this BS?

Where's the nice button? Did you pour in the rain?

I am trying to help you pinpoint the problem. Trying another amp in the same outlet with the same speakers will determine if its an amp problem or a house wiring problem. But to make things equal you need to short the inputs of each amp when you test. I'm sure your tube amp has a relatively high input impedance, don't know about the SS amp. But shorting the inputs will make the amp under test amplify ground, this is the quietest an amp can be. In this way it equalizes the test of different amps.

I am not able to play any of your demos of the hum but be that as it may.... I want to make sure I understand ,the ST70 is just a power amp, correct? Line level unbalanced (RCA) inputs to speaker outputs? When you did the 2 prong/3 prong tests were the inputs open or shorted? And do you have any other amp you can plug into the same outlet and same speakers?

If you're talking to me I'll bow out.

Neutral and hot were swapped? Those testers don't check for ground/neutral swapped. Was the green "ground light" on even when the wires were swapped?

All the equipment has 3 prong cords? And un balanced connections? Where does the third wire go on all the equipment? To the chassis and then to the shields of all the un balanced connections?

Mittwock? Its the middle of the week a course.Ya know hump day.

Hey @Braided Where are you located? If your in the US, Monoprice sells a nice Y splitter: https://www.monoprice.com/product?p_id=6261

OMG remote controlled BBQs or smokers? You guys must have busy lives I have a Kamado(big green egg) that I use for everything. Grilling, smoking and in between. But it ain't remote contolled. You having to F'ing pay attention to what you're doing, what a shame.

Toroids do not like DC offset at all. Your Mac is not a toroid. Its this one, right? I had one of these back in the day until it got stolen. Sumabitches. Have you recently changed abodes? I mean is your ambient environment quieter now? When i moved to my house out here in the sticks it was much quieter. The hum from equipment transformers drove me nuts. Unbeknownest to me i built a 2 channel room with perfect dimensions to accentuate 60Hz hum. That's why i remoted all my amps. Many thanks to Bill Whitlock of Jensen Transformers helping me to figure out WTF was going on.

What you talkin'bout? You mean they don't have transformers? SMPS?