Eliminating hum

You should be very careful when using "cheater" plugs or removing the ground prong on a plug.

Equipment ground is there for your safety, removing it eliminates electricity having a safe path to ground.

Solving the source of your problem - a difference in potential with the different grounds in your system - is the best way to solve the problem.

Try using a single circuit. If that's not practical, try using a single circuit for your amplifiers and another single circuit for your source components.

If this doesn't work, you'll need to identify the source of the hum. Unplug a single component, one at a time, to see if it removes the hum - trying the preamp last.

Once you find the source(s), try plugging them into a circuit common with other parts of the system. Say a transport is the problem and it's plugged in a separate circuit, try plugging it in with the rest of your source components, or your amplifier(s) - in that order.

If all your equipment is plugged into a common circuit, than your equipment is suspect and it is NOT recommended to remove the ground prong of the plug.

Good luck and hope this helps.

Thanks for the info. One more question. If there is a hum generated from a ground loop would it be there say at the end of a song or between tracks when listening to the CDP?

I had a hum caused by me Eastern Electric MiniMax DAC Plus when I added it to my system. I used an Ebtech Hum-X with it and the hum went way. I got the Ebtech Hum-X from Guitar Center on sale during the holidays. It is a safe cheater plug that can handle up to 6 amps of current.

Like others have stated start at the preamp and sources first.

Ground Loops and hum have been the source of many discussion hear on Audiogon. I would suggest that you do a search of ground loops and hum and read a few.

That said, ground loops can be caused by several things.

1. Poorly designed and constructed equipment with insufficient grounding schemes. This is the hardest to fix because the item itself is badly designed.

2. noise generated by home items such as lights, refrigerators, motors, etc.

3. poor interconnects, where the return and shield are connected.

4. Poor electrical connections where neutrals are shared by other lines. This happens a lot.

5. Poor electrical connections of the audio components.

As was mentioned previously, you must first find the source of the problem in your system.

The best way is to unplug and disconnect all the components except the amplifiers and speakers and then turn the amps and speakers on. Noise? no? Then move on to the next section. Noise? yes? Then it is the amps.

Connect the active crossover (if you have one), if not connect the pre-amp to the amp(s). Make sure all other components are unplugged and disconnected (interconnect cables) and only the crossover or pre-amp, amp and speakers are connected. Noise? yes, then it is the crossover (if you have one), interconnect cables, or pre-amp. No noise? Then move on.

connect a source component to the pre-amp and plug it into. pre-amp, amp and speakers are still connected. Noise? yes, then it is the source component or interconnect cables. No? then it is another source component that plugs into the pre-amp and test those.

Also, and very important to lower the noise floor extremely and to help eliminate ground loops are dedicated lines and proper connection of low level components.

I always advocate at least three dedicated lines. More depending on what you have. Two dedicated lines. One for each amp and one additional dedicated line for all of my low level source components. My low level source components (pre-amp, active crossover, tuner, cd transport, DAC, turntable) are all plugged into a power conditioner ( I really like the Transparent Audio Power Isolator 8 unit) which is in turn plugged into its own dedicated line. This helps eliminate ground loops.

The problem arises when your system is sharing a line with other stuff in your house before the electrical panel, such as the lights, and refrigerated.

Also, a dedicated line is as follows: A hot, neutral and ground wire "dedicated" solely for the one pair of outlets, which all three together go to the electrical panel and the neutral is not shared.

12 gauge or 10 gauge "romex" with hot, neutral and ground per line to the panel.

I had a ground loop the other day only to discover that I had accidentally plugged one component's power cord into the same outlet as my low level components connection. When I corrected this by plugging it into its own dedicated line (as it was supposed to be), the ground loop disappeared.

You don't need cheater plugs to find the source of a ground loop. Just follow the instructions above. People use cheater plugs to "fix" the ground loop and that is not the proper way to go. It is totally unsafe and being in the power/electrical field, is really......stupid. Once you discover the cause of the ground loop. Fix the problem.

enjoy

Using cheater plugs is completely safe and often effective.