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
amg56's avatar
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amg56
887 posts
 
Hey Customerfirst, it would seem you have tested all the configurations. Your conclusion would seem unlikely, but possible. BOTH preamps with problems?

What models are the amp/preamps? How old are they?

I would also agree with rixthetrick that there may be a dry joint or component failing in each (you need to be unlucky).

If you were talking about some sort of room treatment of a dubious source, you might attract more notice and help.

If I can think of anything further I’ll pop my head in and see how you are
doing. Good luck from me. 🇦🇺
rixthetrick's avatar
rixthetrick
1,060 posts
 
Do you have a competent electronics repair service in your area, especially a service agent for reputable hifi brands?
Perhaps you could get on Google and look for one, especially if you're in a highly populated area.

A good service agent should be able to with the correct tools identify the problem and give you ideas on costing to repair the device/s
basilfudge
3 posts
 
You may have mentioned this, and I missed it, but: Any chance there could be something going on with the speaker? 
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.
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