Radio Noise from left speaker

ecod123

I recently purchased a used Melody SP3 tube power amp. It worked well in my main 2 channel setup. Then I decided to move it to another room to try it out with my horn speakers because a friend suggested these will match well.

After setting up last night, I was getting radio noise from the left speaker (but not from the right) in the new setup, which wasn't there before I added the tube amp. Previously had my Denon avr running the speakers but now I used the Denon as a pre-pro to the tube amp.

Tried swapping the speakers cables but left channel radio noise remained. Drove me nuts trying to figure out the cause late last night, unsuccessfrul and ended up needing extra shot of java joe this morning to get me going.:D

Can someone help this noob out with some pointers or a solution?

Thanks in advance.

[Deleted User]

Hello,
When you say "radio noise" do you mean a radio station is coming through the left channel? But not the right channel, correct?
Regards, Ken

Hairsonfire

ecod123 wrote: »

I recently purchased a used Melody SP3 tube power amp. It worked well in my main 2 channel setup. Then I decided to move it to another room to try it out with my horn speakers because a friend suggested these will match well.

After setting up last night, I was getting radio noise from the left speaker (but not from the right) in the new setup, which wasn't there before I added the tube amp. Previously had my Denon avr running the speakers but now I used the Denon as a pre-pro to the tube amp.

Tried swapping the speakers cables but left channel radio noise remained. Drove me nuts trying to figure out the cause late last night, unsuccessfrul and ended up needing extra shot of java joe this morning to get me going.:D

Can someone help this noob out with some pointers or a solution?

Thanks in advance.

Try using a different power outlet. Get a really long extension cord too. Move the speaker wires if you can. Your system is acting like a big antennae and you need to change something. I had to use a different power outlet. Good luck!

ecod123

Kenneth Swauger wrote: »

Hello,
When you say "radio noise" do you mean a radio station is coming through the left channel? But not the right channel, correct?
Regards, Ken

Ken,
Yes, getting a radio station from only the left channel, and not the right. Thanks.

ecod123

Hairsonfire wrote: »

Try using a different power outlet. Get a really long extension cord too. Move the speaker wires if you can. Your system is acting like a big antennae and you need to change something. I had to use a different power outlet. Good luck!

Unfortunately, all the cables/wire/cords are along a tight space behind an old style entertainment system and I am using a surge protector connected to the only power outlet I have there.

The radio station noise wasn't there before I introduced the tube amp. Will try moving the wires around to see if that helps when I get home.

[Deleted User]

Hello,
Usually vacuum tube gear isn't too sensitive to RF, but obviously not in your case. I think I would try a few simple tests first. At the preamp swap the right and left RCA cables and see if it changes channels. If it does then you know the problem is not with the power amp, speaker wire or speakers. If it doesn't change channels, then swap the RCA cables at the amplifier. The goal is to make it change to the right channel. If the problem is in the amplifier then no matter which speaker is connected to the left channel there's RF. But a slow process of elimination is the best method.
It goes without saying that you should always power down the amp whenever making any cable changes and maybe give the amp a few minutes before you turn it back on so the power supply can discharge.
Regards, Ken

TECHNOKID

Kenneth Swauger wrote: »

Hello,
When you say "radio noise" do you mean a radio station is coming through the left channel? But not the right channel, correct?
Regards, Ken

Hairsonfire wrote: »

Try using a different power outlet. Get a really long extension cord too. Move the speaker wires if you can. Your system is acting like a big antennae and you need to change something. I had to use a different power outlet. Good luck!

ecod123 wrote: »

Ken,
Yes, getting a radio station from only the left channel, and not the right. Thanks.

I've experienced that once during a set-up. In this case it was a bad microphone XLR connection causing the issue. As pointed out above some cable is acting as an antenna. This would more likely be caused by an open somewhere in the chain. You are saying that you swapped the cable and the problem remained. It seem the problem could be coming from the amp it self however, your next step should be to do some more swapping;

1. Have you tried swapping speakers, if not I suggest you do so.

2. Another thing to do is to relocate the path of the cable as you mentioned you didn't have this problem in your other room. make sure your cables don't cross and are far enough apart (powers and signal cables) as this may also create some unwanted transfer between cables.

GL and keep ua posted of your results

Cheers!
TK

ecod123

Thanks everyone, will try out the different suggestions later this evening and report back once I isolate the source of the problem.

txcoastal1

Isn't that the same problem Gilligan had:D:D:D

ecod123

txcoastal1 wrote: »

Isn't that the same problem Gilligan had:D:D:D

LOL. Luckily, I am not on a deserted island.:D

ecod123

Reporting back on the radio channel problem. Was a little busy so couldn't do much. But pretty much ruled out the tube amp as the source. Will probably have time this weekend to run a full blown testing.