Help with Hum issues.

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.

This is all RCA cables.  Speaker wires are just regular wires.  I changed all the cables and wires and no difference.  The Hum is always in the R. side.

Sorry I meant the spkrs connected to the Amp.

It is NOT the tuner.  If you read my post, different sources have been tried.  The hum is always there.

Without a speaker connected to the right side of the pre amp there is no hum.  The hum does not come on by turning the amp or pre amp on if there is no speaker connected.

It is not the speaker because I tried different spekrs and wires.  It is not the equipment because I tried different setup/equipment and still have the hum in the R. side.

Ok. I am responding to 2 people here since I don't see how to respond individually.

To Newbee:

What IC's ?  What are you talking about ?

I have tried other outlets....read my post.  Other amps, pre-amps.

To Tvdad:

I did that, the hum switches with the wires to the Left side....thus it is in the R. side (the hum that is).

Correct me if I am missing something here.

Thank you all.

Ok, I did that again and here is what happened:

Disconnected everything.

Plugged the Amp in with speaker attached.  No hum.

Plugged pre amp and attached it to Amp.  When I turned on the pre-amp the hum is back.

All is plugged into the same power strip.

My understanding is that I would not get a hum anyway by just plugging in the Amp since it needs a pre-amp to do anything.

So I doubt it is the pr-amp that is causing the hum.

Again...I was using a different pre-amp and amp before and I was still getting the SAME hum in the Right side....no matter what speaker or wire I used.

By the way None of these components have a 3 prong plugs.  They all have 2 prong AC plugs.  There is a Ground screw on the back of the pre-amp.  Grounding it is making no difference.

Changed the RCA cable to Gold Plated "Monster cable", the hum is still there.

Plugged it all into a different outlet.  Hum is still there.

This is just the amp and pre-amp, no source is plugged in to keep things simple.

Does not matter what source I add (Tuner or Turntable) the hum is still there.

I read at article about using one of those computer back up batteries for "Clean" AC power.

Will try that next as I am running out of things to try.

Didn't we do this already 2 steps back ?  I am sure we did.

This is all becoming too confusing and hard to follow.

Let me state (To simplify this hopefully) how this all started and where I am now:

I started out connecting an Onkyo large Amp and matching pre-amp.  Had a hum in the R side.  Grounded it every which way, sometimes it is better than others but the hum is never gone.

I noticed the Phono stage on the Pre-amp is often faint or fades away.

So I replaced the Onkyo pre with a Phase linear pre.  I still have the hum.

So I removed the Onkyo Amp and replaced it with a Mitsubishi Amp.  The hum is still there (NO matter what source or NO source).

This is also true with the Original set up (ALL Onkyo)

So just now, I did the following:

To complicate things further or maybe not:

I removed the Phase linear pre amp and connected the Onkyo pre amp instead.  Connected to the Mitsubishi amp.   I also connected a Tuner as a source.

The hum is gone but the Onkyo pre amp has issues with the phono stage and the L, R, Mono switch....as I mentioned above.  I have cleaned the switches with the spray but the issue is not resolved.

And when I had the Onkyo amp connected to it I had the same hum issue.

So what does this mean ??

I guess the Phase Linear pre amp is causing a Hum ?

And the Onkyo Amplifier is also causing a hum ?

And I need to fix the Onkyo Pre-amp as a Minimum and maybe the Onkyo Amp if the hum doesn't go away.

Ok, I hope things are clearer now.

So I tried these different setups:

1- All Onkyo (Amp, pre-amp).  Hum in R. side.

2- Onkyo Amp, Phase Linear pre-amp.  Hum in R. side.

3- Mitsubishi Amp.  Phase linear pre-amp.  Hum in R. side.

4- Mitsubishi Amp.  Onkyo pre-amp.  Hum is gone.  But there are the issues with the pre-amp that I stated. 

I eliminated the signal source (Tuner) since it is not the issue here.

All cables and speakers were changed so those are not the issue either.

What are the odds that the Onkyo amp and P. Linear pre-amp needs repair in addition to the repairs needed on the Onkyo pre-amp ??

And would any of this cause the Hum ?   I don't understand.

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.