Is cheater plug safe with grounded monster power?

thanks tbg. it has a 12V output and is made of plastic.

Ldatlof - the "brick" performs the same function as a wall-wart. It takes AC in, puts DC out. It is an outboard power supply.

Since the power supply supplies DC through the mini-plug connector that goes into the dock, there is no AC current in the dock. So, it was never grounded to your house AC system in the first place. With a cheater plug in place, the outboard power supply is not grounded for sure. Whether is is going to cause a problem or not, I don't know because I've never looked at the inside of the PS. Usually though, there is a reason why earth ground is connected.

Look in your manual. Does it say something like, "this product must be plugged into a properly grounded outlet?"

Greetings!

I have read this thread with interest, and I am no closer to solving my ground loop issue.

Now, I don't want to appear overly stupid, but I thought electronics was an exact science based on math and physics. By reading this thread, I get the opposite impression.

So what IS the best way to eliminate a ground loop? Cookbook advice is always welcome. Telling me to isolate a component, for example, does not tell me how to carry out that procedure. Remember I don't have multiple degrees in electrical engineering plus an electrician's license.

The system in question has the following components:

Proceed AMP 5 (five channel amplifier)
Proceed AVP (five channel preamp)
Sony DVD player
Muse Model 18 powered subwoofer
Martin Logan Ascent loudspeakers

When the Muse Model 18 was connected between the amp and preamp using RCA ICs, a ground loop condition occurred. I tried cheater plugs on the power cords of the AMP 5 and the Muse Model 18. The hum was reduced, but not eliminated.

When I removed the Proceed AVP and the Sony DVD player and used a Klyne System 7 preamp plus a Musical Fidelity CD player while still using the Muse Model 18, there was no hum at all.

I would like to be able to use the Proceed gear, the Sony DVD player, and the Muse Model 18 to watch movies.

Any help you can provide would be appreciated.

Regards,

Artar1 -

Give me some additional information:

1. List the components that have a three-prong grounded power cord, including the substitutes.

2. Are you using dedicated circuit(s)?

3. Are you using a power conditioner? If so, which model?

4. Are all devices plugged into one circuit, or into more than one circuit?

5. Are you using aftermarket power cords? If so, which models, and on what gear? If you are not, please tell me what the wire gauge of each of the three-wire cords are. It will be embossed on the cord jacket.

Rex, On your question #1 please bear in mind that most Japanese products come with three prong plugs but few have the ground attached to anything. Many don't even have a third, ground connector at the unit.

Artar,

I recommend the following procedure to at least identify the culprit.

1. disconnect everything except the amp to speaker wires. Put shorting plugs into your main amp and turn it on. If you have no hum, the culprit is not the amp.

2. Connect the preamp to the amp after removing the shorting plugs. Turn the preamp on and then the amp. If you have no hum, neither are culprits.

3. Plug in one front end device. If you have no hum, with it active, it is not the culprit.

4. When you add something that causes hum, it is the culprit. It is possible that it is that unit's interconnects, so try others. Also it may be the only grounded front end device. Try a cheater plug. If the hum does not go away, try reversing the cheater. If none of this works, you have a problem with that device.

If the hum goes away with the cheater, which will typically be the case, you have an issue--do you need it grounded? Rex would answer one way and I another.

You might also find that grounding the unit to the amp may cause the hum to go away. Also a resister on the ground may solve the problem.