On September 1, 2018 at 10:59, highfigh said...
I was asking for a simple answer, but OK.
You asked a question so simple that there was no simple answer, unless you would accept "Yes and no" or "Depends" as an answer. I thought those answers wouldn't help. My answer didn't leave it at one or two words but instead described the conditions under which "Yes" and "No" would be accurate answers.
Does it strike you as strange that most source devices don't have a grounded power cord and receivers, preamps and some integrated amplifiers do?
No. This completely avoids problem ground loops through the power cord and chassis. Note carefully that I said PROBLEM ground loops.
Ever measure the resistance from the ground ferrule on a source device and its chassis? They're often separated. I've seen that. I've seen a power amp (Citation 12) with a small resistance between amp ground and chassis. And when a capacitor got leaky, that resistor just smoked right up!
If the system is more simple and consists of a receiver with preamp out to a separate amplifier,
I should probably stop writing here since I don't know of a system with a receiver (which has a preamp in it, that is to say, source selection, volume, etc) WITH a preamp (unless you mean to say that the receiver has a preamp, which they all do)... so I'm not sure what you're talking about.
it could be said that the receiver is the source- that's the reason I asked in the way I did. Even a preamp and separate power amp that have grounded power cords and use XLR connections can have ground a loop, under the right conditions (or wrong, depending on how the building was wired)- I worked on a house with this condition when I installed a Krell preamp and power amp, using Canare cables. Changing to unbalanced cables cured it completely.
This probably has to do with how the ground was handled in the balanced wiring. It's definitely not true that an unbalanced connection, which gave you success here, is a better way to connect than balanced. As you say, there's no single method that works best in all situations. That's because each situation has certain things built into it that can make a good connection system have a problem.
Why did I use the word PROBLEM up above? The average system has many ground loops. The easiest to visualize is the analog audio connection of a player to a receiver or preamp or processor. There are two channels, and the ground of each channel of the player is connected to the ground of each channel of a preamp input. That's a ground loop.
We don't care about and don't even perceive ground loops until they cause a problem.
I'm sure you have seen this- there's no single method that works in all situations.
[Link: rane.com]I know thjs is now a long discussion. Still, I bet you would not have wanted me to answer "Yes and no" to your original question!
