Chaps, equipment power polarity matters. I've been checking and altering it since the 1970s, particularly with monoblocks. Manufacturers don't always measure their transformer polarity and there can be discrepancies. I once got a 250V CT transformer that was symmetrical about the CT from a manufacturer that claimed 100% goods outwards test.
This image shows what happens when polarities are inverted with monoblocks.
http://ielogical.com/assets/M-125/PTPolarity.jpg
This link gives an example of miswired power transformers: ieLogical VTA M-125 HowBad - note the difference in the noise with the polarity reversed.
Articles on AC Polarity:
https://www.gcaudio.com/tips-tricks/determining-proper-ac-polarity/
Transformer Polarity | Energy Central
When AC polarity is correct, another of the proverbial veils is removed.
To make a polarity check adapter, get a cheater plug with a ring Earth Safety terminal. File down the neutral so it fits the line. Solder a piece of 12ga stranded to the Earth Safety tab and add a large insulated banana plug to the other end. 4897-0 Pomona Electronics | Connectors, Interconnects | DigiKey Expand the leaves slightly to ensure a good connection. Plug the banana into the neutral on the other socket. If it's used, temporarily use a cube tap to increase the available outlets.
NEVER EVER lift the Earth Safety. FIX the BLEEDING PROBLEM!!!
The life you save may be your own.
This image shows what happens when polarities are inverted with monoblocks.
http://ielogical.com/assets/M-125/PTPolarity.jpg
This link gives an example of miswired power transformers: ieLogical VTA M-125 HowBad - note the difference in the noise with the polarity reversed.
Articles on AC Polarity:
https://www.gcaudio.com/tips-tricks/determining-proper-ac-polarity/
Transformer Polarity | Energy Central
When AC polarity is correct, another of the proverbial veils is removed.
To make a polarity check adapter, get a cheater plug with a ring Earth Safety terminal. File down the neutral so it fits the line. Solder a piece of 12ga stranded to the Earth Safety tab and add a large insulated banana plug to the other end. 4897-0 Pomona Electronics | Connectors, Interconnects | DigiKey Expand the leaves slightly to ensure a good connection. Plug the banana into the neutral on the other socket. If it's used, temporarily use a cube tap to increase the available outlets.
NEVER EVER lift the Earth Safety. FIX the BLEEDING PROBLEM!!!
The life you save may be your own.