2. amps-preamps
  3. 157716-124365

Help with Hum issues.

I need to pick your brains please:

As I am going crazy with this issue:

Everything listed is Solid State.....NO tubes.


Ok, so when I had my Onkyo Amp and pre amp connected, I had a hum in the Right Chanel. This is the same Onkyo Amp where I ended up burning the transistor and fuse because I was trying to eliminate this Hum issue.

It sounds like Vooohhhh. and it is constant.


I thought it was the Amplifier.


Now I have a Mitsubishi amp connected to a phase linear pre-amp and a separate tuner. The Left Chanel is clean and has no hum noise, when I switch the speaker wire (same speaker & wire) to the Right side I get that same hum again I was getting in the other setup.


This same hum was happening when I lived in a different city.


I don't understand what or why this is happening. I replaced components, wires, speakers, outlets where the components are plugged.  I plugged everything into one power strip, different strips, into the back of the pre-amp and made no difference.


Why do I keep getting this hum in the R side Only ?


It is driving me nuts and don't know how to get rid of it. I grounded the system every which way, it made no difference.


Would appreciate any help.


Thank you,
customersfirst
twoleftears's avatar
twoleftears
5,318 posts
 

Step 1: identify the culprit by a process of elimination.

If you swop the IC's from the source to the preamp over, does the hum change sides, or stay the same.  If it stays the same, it's not the source.

Restore source to normal, and swop IC's over from preamp to amp.  If the hum changes sides, it's the preamp, if it doesn't, it's not.

Restore IC's to correct positions. Swop speaker cables over.  If the hum changes sides, it's the amp, if not then, well, it must be the speaker.

Step 2: experiment with different grounding of electrical supply to guilty component, dressing of cables, etc. etc.  If nothing works, it's internal, and yes, you need to seek out a repair person.

customersfirst OP
12 posts
 
Just to be clear...what do the following statements mean:

If you swop the IC's from the source to the preamp over ?

Restore source to normal, and swop IC's over from preamp to amp ??


What am I starting with here....Amp, pre-amp and tuner ?  Then what ?

Please be more clear.

Thank you.
twoleftears's avatar
twoleftears
5,318 posts
 

Interconnects from CD-player/DAC/phono amp, whatever the source is.  Leave the interconnects as they normally are at the source end, but change over L to R and R to L at the preamp end.  Audition.  Has the hum changed sides or not?

If not, continue on down the line, doing this same experiment at each stage of the chain.  source-->preamp; preamp-->power amp; power amp-->speakers.  If the hum changes sides at any point in this experiment, it's the component providing the signal at that point that's at fault.

If it never changes sides, you're SOL and need more expert help.

customersfirst OP
12 posts
 
I've already said that the hum changes sides but it is not the FM tuner that is the issue since it works just fine in another set up.
ozzy's avatar
ozzy
7,539 posts
 
Just by ear buds... and give up.

ozzy
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