2. amps-preamps
  3. 1255755103

Mother of All Ground Loops

Hoping somebody out there has had something like this happen and can help a brother out.

I have owned for the past year Odyssey Stratos Mono Extreme SE amplifiers.

Recently, in an effort to upgrade my system, I got a great deal on a custom Response Audio preamp.

I waited for it to arrive, hooked it up, and there was only the faintest sound of music coming through it.

I then went to make sure that the interconnects in the back of the unit were okay, and in doing so got shocked.

I immediately panicked and sent the preamp back to Bill at Response Audio (awesome customer service, Bill is truly an honest and awesome guy to work with), who thoroughly checked it for any defects. Nothing. Preamp was in perfect shape.

For the few days that the unit was at Response, I had hooked up my Odyssey amplifiers to a receiver to have some capabilities. Everything worked out okay; albeit the sound was not so hot due to the receiver sucking as a preamp.

I got the Response preamp earlier tonight, and hooked it up the same way again to NO improvement. Hardly any sound, and shocked on contact of anything plugged into the outlet and made of metal.

I decided to hook everything up to an Emotiva amplifier I had laying around, and the preamp worked beautifully!!

So, its obvious that there is some major grounding issue with the preamp and the stratos amplifiers...

The problem is, how do you fix this?

I can't afford right now to replace either at the moment, and the sound is tolerable through the Emotiva, but I can tell a lot is missing...

Is there a cure for this problem?? Is it hopeless?

I fear sending back the amplifiers to Odyssey; at what would likely be several hundred dollars to ship and potentially getting damaged during shipping if there is nothing that can logically be done.

What can one do?

kingdeezie
magfan
1,583 posts
 
WHEN you reach a resolution, please POST.

What I suspect is a ground /neutral OR hot /neutral reverse, and I can't tell which OR which piece!

Did you use a DVM to check voltages?

I'm really curious, since this will help everyone eventually.
hifitime
715 posts
 
Also,there could be a capacitor leaking,shorting, or other part tied to the ground(chassis)that will pass voltage to the metal case.If it is new,it may have been miswired also.
kingdeezie OP
92 posts
 
I sent the preamp back to Response Audio, and Bill there said that everything was perfectly fine.

I bought this unit used, so someone else was using it before me for a year with absolutely no problem.

Both amplifiers cause the same problem with the preamp, even when Isolated from each other hooked up one at a time.

The amplifiers also work completely fine with my HT receiver.

I am going to send these amplifiers back to the company to get looked at by Klaus.

This way he can make sure they are 100 percent okay before I post them for sale.
jea48
4,416 posts
 
I am going to send these amplifiers back to the company to get looked at by Klaus.

You might want to send the preamp along with the amps.
Could be a coupling problem between the preamp and power-amps.

You never said in your posts if a moderate to loud hum was heard through the speakers with the preamp connected to the amps. You only mentioned the volume of sound was faint.
kingdeezie OP
92 posts
 
I do think its a coupling problem between the amplifiers and the preamp; but I am not going to be sending the preamp as well.

There WAS a hum.

I am sending them to Klaus to make sure they are okay to sell.
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