Ungrounded interconnects...help, please

[fenixdown110]

Of course the manufacturer will tell you its alright. He wants you to be happy and not necessarily safe.

 

[nattonrice]

Quote:

Originally Posted by Suprfly2k /img/forum/go_quote.gif I contacted the manufacturer of the head-phone amp, and he said that there would be no problem removing the ground from the power.

No problem in the sense that it won't stop working...
Safety wise that is a very bad thing to do.

 

[Suprfly2k]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif If by that he means defeating the power cord's safety ground, that's a very irresponsible recommendation in my opinion. se

No harm to the amp.

Risk of death by electrocution.

 

[fenixdown110]

Quote:

Originally Posted by Suprfly2k /img/forum/go_quote.gif No harm to the amp. Risk of death by electrocution.

That's what I call highly recommended.

 

[Suprfly2k]

So this thread has got me thinking, and worrying.

I have and use extensively some vintage gear...two McIntosh MC60 power-amps and a Fender Champ guitar amp; the former from the 50's and the latter from the 60's. None of these has a grounded power-cord.

Am I foolishly risking death by using these? Do I need to retro-fit them with a grounded power cord?

Thanks for your input.

 

[Anonanimal]

Well I believe the idea behind a grounded cord is to keep you safe just in case you get an internal problem on the AC side. For example- if one of the AC leads came loose inside the amp it could potentially short to the chassis of the unit (if the chassis is metal), which would of course shock you if you touched it. Grounding a metal chassis will lessen the danger such an occurrence would pose.

I'm sure there are other possible reasons but that's the most obvious one that I know of.

 

[Suprfly2k]

That's my understanding, too. The MC60's also have a metal chassis, and it seems I might face electrocution through the electric guitar should the Fender short.

Or do I have my..ahem..wires crossed?

 

[Suprfly2k]

I'm still trying to get my head wrapped around this.

Of all my components (phono stage, DVD player, CD player, power amps, receiver, headphone amp), only the head-phone amp has a grounded power plug.

Does this have some impact on my problem?

 

[Steve Eddy]

Quote:

Originally Posted by Suprfly2k /img/forum/go_quote.gif I'm still trying to get my head wrapped around this. Of all my components (phono stage, DVD player, CD player, power amps, receiver, headphone amp), only the head-phone amp has a grounded power plug. Does this have some impact on my problem?

Question.

With the ground of your headphone amp NOT defeated, do you get any hum with any of your source components connected directly to the amp?

se

 

[Suprfly2k]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif Question. With the ground of your headphone amp NOT defeated, do you get any hum with any of your source components connected directly to the amp? se

No.

I appreciate your putting some thought into this.

BTW...today, I plugged every component into a single power conditioner and the hum persisted. I removed just the headphone amp's cord and connected it to a different plug, and the hum persisted.

Also, I bypassed the new switch and used my receiver as a switch (connecting the head phone input to an analog out on the receiver)...same hum.

Also, when I disconnect all inputs to the system, the hum persists.

So, I seem to only get the hum when the head-phone amp is directly connected to the receiver (either through the mechanical switch or via direct interconnects to an analog out terminal).

 

[Steve Eddy]

Quote:

Originally Posted by Suprfly2k /img/forum/go_quote.gif So, I seem to only get the hum when the head-phone amp is directly connected to the receiver (either through the mechanical switch or via direct interconnects to an analog out terminal).

Receiver? Hadn't seen that mentioned previously.

Is your receiver connected to any sort of cable or satellite box?

se

 

[Suprfly2k]

The receiver is connected to a cable box via optical, audio, and component video. I disconnected the coax feed to the cable box, and the hum persisted.

I also unplugged the power of all components except the phono stage and headphone amp, and the hum persisted. When I disconnected the unpowered receiver from the mechanical switch, the hum goes away.

I have a bad feeling that it's an RFI problem of some sort, not grounding. I had a similar issue with my turntable that I could not isolate to a funky ground and resolved it by constructing a steel mesh Farraday cage around the turntable .

I hope I don't have to go down that road gain.