New main amp, now left Vantage has a buzz

[Kaboomnash]

Hey folks, I received my awesome Pass Labs X-250 direct from their factory after getting a total recondition. I have the inspection paperwork and the warranty to prove it.
Before installing the amp my Vantages sounded wonderful and total silence when void of musical notes. Now after installing my X-250 I have a buzz in my left Vantage, quite loud. It is only the left side speaker. If I put my amp in standby the noise goes away.
Any ideas where to start looking for issues? I have Audioquest interconnects and Audioquest speaker cables.

Thanks, Lee

 

[Kenscollick]

I would start by switching the speaker cables if the noise is then in your right speaker the problem lies with the amp.

 

[MotorToad]

First I'd swap the cables in the amp and see if it's the left channel or the left speaker.

Bah, totally ninja'd! Most likely it'd be the amp, since they were fine before.

 

[amey01]

It's most likely the amp i'd say. As long as there are no ground loops there - both speakers plugged in to the same socket?

Do you have your old amp to verify?

 

[Diamonds]

is the gain kicked up higher in one channel via the preamp? What are you using for a preamp?

 

[Gordon Gray]

Check your interconnect

Lee,

Had this happen one time. Turned out to be a soldering issue with the interconnect. Just a thought.

GG

 

[Cherian]

I would switch L and R from the amp to the speaker and see if the noise moves to the other side. Then I would switch the L and R on the preamp to see if it noise switches again. If the noise only switches side the first time its the amp. If it switches sides the second time then its the preamp.

 

[Audioseduction]

Any updates? I also think it's the amp.

 

[Gordon Gray]

I would switch L and R from the amp to the speaker and see if the noise moves to the other side. Then I would switch the L and R on the preamp to see if it noise switches again. If the noise only switches side the first time its the amp. If it switches sides the second time then its the preamp.

In Scenario 2, it could also be a grounding problem with the INTERCONNECT.

 

[Kaboomnash]

Do you have your old amp to verify?

Yep, both are plugged in at the same location.

 

[Kaboomnash]

is the gain kicked up higher in one channel via the preamp? What are you using for a preamp?

Nope, run the interconnects from the AVR.

I switched Interconnects and the buzzed stayed with the left side Vantage.

 

[Kaboomnash]

Any updates? I also think it's the amp.

Thanks for all the help. I switched the speaker cables and it switched to the right side. I am worried it might be the amp, crap!

Tim (MiTT) from this forum is supposed to stop by tonight to have a look and listen. Fingers crossed.

 

[Audioseduction]

Thanks for all the help. I switched the speaker cables and it switched to the right side. I am worried it might be the amp, crap!

Tim (MiTT) from this forum is supposed to stop by tonight to have a look and listen. Fingers crossed.

Good thing it's under warranty!

 

[Kaboomnash]

Very cool, my Logans are once again crystal clear.
Pass Labs was ready to ship me another amp, and return ship this amp at no cost to me. But, they suggested I try a $.69 cheater plug from Home Depot and wow what a difference.
No more hum, or buzz in the Vantages. I am so happy.
I rearranged the component rack, subwoofer and the left side Vantage locations to get the new amp into it's spot in the room. I will update my pics in my member system page soon.

Lee

 

[Cherian]

The dreaded Ground loop!! Glad it all worked out for you.

 

[timm]

kaboom - i had the same issue with my descent. guys here walked me thru everything - suggested a cheater plug - I went the route of finally taking it back to a dealer ... and no problem (befoe I bought the cheater plug)... but nothing else in my system ever had an issue - and I have some things with the 3 pronged plug...so - go figure... when you swapped the cords....dang - how could it be anything else???? well, congrats for you... i know the feeling...

 

[Bernard]

I hate those cheater plugs. The ground is there for a purpose - to protect you in the event of a fault.

A friend of mine told me that once at a party he put his hand on the amplifier to see how hot it was as they had music at a high level. The jolt he got made him spill his beer all over his clothes; the host was using a cheater plug and something obviously went wrong.

What I would do after plugging everything into the same wall outlet (no cheaters) is get a cheap $2 interconnect and cut off the RCA plug at one end, leaving with it a short length of the cable. Then strip both exposed ends and connect only the centre lead, not the ground shield. Insert this cable between various components until the hum disappears. Turn down the volume control while plugging/unplugging the cable.

 

[Spike]

Very cool, my Logans are once again crystal clear.
Pass Labs was ready to ship me another amp, and return ship this amp at no cost to me. But, they suggested I try a $.69 cheater plug from Home Depot and wow what a difference.
No more hum, or buzz in the Vantages. I am so happy.
I rearranged the component rack, subwoofer and the left side Vantage locations to get the new amp into it's spot in the room. I will update my pics in my member system page soon.

Lee

Lee,
Most of the time, the groundloop problem originates from the video side of the system. Now that you know it's the groundloop problem, you should see which component is the culprit in order to address the problem in the proper fashion. The 3-prong ground plug were made for a reason and should not be...cheated! One thing you can do quickly is to unplug the video cable from your system (receiver) and see whether the hum goes away without using the cheater plug. If the hum goes away, you'll need an groundloop isolation transformer like the "Cable TV GroundLoop Isolator" from Jensen. A little more than $0.69 but that is the correct solution to the groundloop problem.

Here's the link to Ground Loops, Let me hum a few bars which has good information on the ground loop problem.

Good Luck
Spike