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

Showing 6 responses by amg56

amg56's avatar
amg56
887 posts
 
Ho Customersfirst,  You mentioned that you changed all the wires etc. Did you mean that you changed them with same but new cables (wires)? Or are the cables the same original ones but swapped around? Are the speaker cables terminated with plugs or just bare wire?
I noted the that you swapped the interconnect (IC) between the preamp and amp and heard that the hum followed.
I am giving thought to this. It appears to me that (a possibility), one of your sources could be damaging the preamp.
You did say that you bought a new amp and pre.
Until later 🇦🇺
amg56's avatar
amg56
887 posts
 
Thanks Tvad 🇦🇺
amg56's avatar
amg56
887 posts
 
I think that was the left preamp out to the right amp in. The the right preamp out to the left amp in. 🇦🇺
amg56's avatar
amg56
887 posts
 
Further to that thought, could a speaker feedback or amp feedback to the preamp be causing the hum?
If you search this forum you will see various views on ac regeneration and batteries etc. Worth reading when you get too frustrated! 🇦🇺
amg56's avatar
amg56
887 posts
 
The hum could (I stress could) be damage caused by a source to the preamp. You mentioned that you changed the preamp and amp to new ones but nothing else. It seems unlikely to be cables after your experimenting, so, if the preamp has the same (right) channel damage as before in your old Onkyo, I would suggest that a source (same as connected to the Onkyo) is causing damage to the preamp. Have you connected the same original sources to the same inputs as you had them in the Onkyo? Obviously the turntable will be connected to phono.
Other A’gon contributors with better electrical experience than myself might chime in here, but I was thinking that a source might be causing damage to the right channel of the preamp. 🇦🇺
amg56's avatar
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. 🇦🇺
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