So I noticed there are buzz/hum at random time when I turn the amp on. But tonight I decided to find out what caused such annoying buzz/hum. And I found it.
1/ Amp (grounded) connected to speakers only: turned on, it happened.
2/ Preamp connected to amp then speakers: still happened (only amp was grounded)
3/ I use another amp, it still happened.
4/ So I took sometimes to think about it, what couldve been the cause? Then I recalled, on step1, I still left the rca cables "A" connected at amp's end! Then I picked another pair of coaxial rca cables "B" (shielded).
I then, did a "A" vs "B" test, with them plugged/unplugged into the amp. I replaced them one after another, then turned amp on, I did 3 times each to make sure.
Result:
A: hum/buzz
B: silent
A: hum/buzz
B: silent
A: hum/buzz
B: silent
--------
A: $350 a pair of 1m
B: just something lying around but shielded.
--------
What couldve been the cause? It's not always happened.
My guess is RFI/EMI?
FYI: those are from England and they're red.
P/s: there's a big antena-like device not so far from my house, I can just walk there in minutes (in a straight line). I believe it's something used to re-cast/amplify the signal from the further away TV station. I think so because long ago, the TV station gave me an offer to put such thing on top of my house and pay me monthly in return, but I refused, so they picked another house/location, which is just across the street. Can take a photo of it tomorrow if needed
P/s2: and local TV station is not that far from my house, I can see its attena from the top of my house, approximately 7km max, in a straight line
1/ Amp (grounded) connected to speakers only: turned on, it happened.
2/ Preamp connected to amp then speakers: still happened (only amp was grounded)
3/ I use another amp, it still happened.
4/ So I took sometimes to think about it, what couldve been the cause? Then I recalled, on step1, I still left the rca cables "A" connected at amp's end! Then I picked another pair of coaxial rca cables "B" (shielded).
I then, did a "A" vs "B" test, with them plugged/unplugged into the amp. I replaced them one after another, then turned amp on, I did 3 times each to make sure.
Result:
A: hum/buzz
B: silent
A: hum/buzz
B: silent
A: hum/buzz
B: silent
--------
A: $350 a pair of 1m
B: just something lying around but shielded.
--------
What couldve been the cause? It's not always happened.
My guess is RFI/EMI?
FYI: those are from England and they're red.
P/s: there's a big antena-like device not so far from my house, I can just walk there in minutes (in a straight line). I believe it's something used to re-cast/amplify the signal from the further away TV station. I think so because long ago, the TV station gave me an offer to put such thing on top of my house and pay me monthly in return, but I refused, so they picked another house/location, which is just across the street. Can take a photo of it tomorrow if needed
P/s2: and local TV station is not that far from my house, I can see its attena from the top of my house, approximately 7km max, in a straight line
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