Because you all are smart!

[Diamonds]

So here is the situation. My son has a Conrad Johnson Met 1 6 channel analog tube preamp. Just this weekend we added a Conrad Johnson 5 channel amplifier. They both were plugged into a Shunyata Hydra power conditioner. When I we turned the amp on we got a loud very audiable hum. So we rechecked our connections and turned everything on again...same hum. So I called my friend because he owns the same Conrad Johsnson two pieces. He suggested we use a cheater plug that goes from 3 prong to two prong.

Sure enough that worked!

I still have a couple of questions though:
1. Is using a cheater plug safe on an amplifier?
2. Is there a better way?
3. Do you think this effects sound?

 

[Audioseduction]

This may have a negative effect on the function of the protection circuit by removing the protective conductor, or earth, which is to provide a low resistance path for fault current so that the circuit protective devices operate rapidly to disconnect the supply. Another words your equipment may just fry to death if there is a fault in the audio equipment!

 

[Bernard]

......... Another words your equipment may just fry to death if there is a fault in the audio equipment!

It may also fry you in the process if you happen to be touching it.

 

[Cherian]

What you have going on is a ground loop. Not running a ground to the amp may not be the safest thing to do. My fear is the chassis of the amp is not grounded. If one of the connections in the amp were to come loose and come across the chassis then you could have a "live" chassis. Then when someone touches the chassis of the amp they complete the loop and bam a shock .

The odds of this happening are very small but still there.

Do you get the hum if you bypass the Shunyata (IE plug everything into the wall)? I’m guessing the Shunyata may cause the hum.

 

[Spike]

From what I gather, it looks like the ground from the cable (or satelite) connection is offsetting with the electrical ground causing hum.

Here are a couple (of many) articles you can read up yourself...
Hum and buzzes
How to eliminate hum or buzz

Good luck
Spike

 

[Bernard]

........
Do you get the hum if you bypass the Shunyata (IE plug everything into the wall)? I’m guessing the Shunyata may cause the hum.

If the grounds in the Shunyata are daisy-chained instead of being connected in a star configuration that could do it.

 

[Audioseduction]

The hums happen when you don't have a single source grounding point.

 

[Diamonds]

What about if I just broke off the ground at the plug. Would that be safer?

 

[Cherian]

No not safer. No difference.

 

[JonFo]

First try and isolate where the ground loop is being formed. So unplug the cable TV set-top or other 'usual suspects' from the pre-amp. Do it one by one and see which one induces the hum.

Then we can take it from there as far as how to cure.

Remember, the sub is also one of the suspects here if plugged into a separate outlet.