And how does one acquire an immunity to interconnect cables? Is it from a consistent exposure to same that you build up a natural resistance to them? Sheeeesh!🤔😝Proper inoculation I guess.
however, my encounter with preamp MP-1 is otherwise. In exactly the same setting, all variables are fixed and nothing changed (ie. interconnects, power etc..), i get hum from MP-1 , but i don’t experience hum after i swap to single ended pre. At a friend place, the same MP-1 preamp function just as great.@philipwu The most likely cause is that the amp you were trying to drive wasn't actually balanced. It may have had the XLR connector (an example of an amp like this is the Lamm 1.1, also any VTL amp equipped with an XLR input), but if the circuit inside wasn't balanced you would totally get a hum. The reason is that the output of a balanced source occurs between pin 2 and 3 of the XLR, and **ignores** ground. If that's connected to a single-ended input, essentially the unused pin (usually pin 3 when this problem shows up) acts like an antenna for noise because the circuit isn't completed! There are several solutions, certain adapters can be made to work, line transformers and its often possible to modify the amp slightly so that it will accommodate a balanced input.
I frequently show at audio shows with speakers that are 105db 1 watt/1 meter and do it with no hum.