fixing hum on Rega Rp6

So if you unplug the PSU, for the TT, from the AC power outlet the hum goes away?

Yes.  I think the hum is from the wall wort for the Rega PSU...

Check out this video. LOL, the guy is a little funny to watch.
https://www.youtube.com/watch?v=CAY2rRsqHLE

The PSU is not a wall wart one though.
As for the wall wart. If the plug in blades are not polarized try plugging it in 180 degrees from the way you have it plugged in now. See if that helps.

Here is an Agon thread I ran across. This is where I found the above video.
Ground Hum with Rega RP6, Exact and TT PSU.
https://forum.audiogon.com/discussions/ground-hum-with-rega-rp6-exact-and-tt-psu

Run a wire from the turntable ground to the preamp ground to eliminate hum!        ALL phono systems require THIS! Do this first before wasting money on another plug-in power supply! I am sure that what Rega provides is fine - they have been in business for decades!            Also, don't waste money on power cords! Contrary to marketing hype they offer ZERO benefit! Wire is the BIGGEST  B.S. factor in Audio!

Hum is caused by a voltage-potential difference between two components. Connecting them together by a piece of wire fixes this and eliminates hum.

roberjerman
185 posts                                                                     12-19-2017 10:31am

Run a wire from the turntable ground to the preamp ground to eliminate hum! ALL phono systems require THIS! Do this first before wasting money on another plug-in power supply! I am sure that what Rega provides is fine - they have been in business for decades! Also, don’t waste money on power cords! Contrary to marketing hype they offer ZERO benefit! Wire is the BIGGEST B.S. factor in Audio!

There isn’t any ground wire or ground lug for a ground wire on the Rega TT.

Rega grounds the arm tube internally by connecting one of the channel signal shields to it. (I believe the left channel) The ground connection to the phono preamp is made through the signal ground wire/shield of the interconnect.

.

My RP6 had some hum at times. I tried running a ground from the TTPSU to the phono preamp. Later diagnosis lead to a bad tonearm cable that was replaced under warranty. Now it is quiet to 50% volume (which is very loud on my system) with very little hum / hiss using a low .3v MV cartridge. If you unplug the TTPSU from the table, do you still get hum? If so, giggle the loop of the tone arm cable just after it comes out of the arm. 

Thanks very much!  I hadn't thought of the tonearm.  I will experiment with this and see.

The problem is intermittent, but I haven only noticed it when the TTPSU is plugged in...

Margot

Does the hum change when you touch the tone arm? Get louder?

No change when I touch the tone arm.  I notice it when I turn on the PSU TT...

Thanks!

@mcanaday,

Did you try as I suggested unplugging the 24Vac TT power supply wall wart from the mains power outlet, turning/rotating it 180 degrees and then plugging back in?

Did you watch the video I provided in my second post?
https://www.youtube.com/watch?v=CAY2rRsqHLE
You would not have to disassemble the 24Vac PSU unit to add the ground wire. All you would need to do is loosen the two screws just enough so you could insert a bared insulated piece of 20 gauge wire that would be sandwiched between the cover plate and chassis of the unit when you tighten the two screws back down. You could even bend a hook on the end of the wire so it would hook around the screw.

Connect the other end of the wire to the ground lug/terminal on the phono preamp.
The ground wire will put the chassis of the 24Vac TT power supply on the same ground plane as the phono preamp chassis.

I think the hum is from the wall wort for the Rega PSU...

mcanaday

Your PSU may be reacting to something on the same circuit.
Get an extension cord and have it go to another room not on the same circuit as the one currently. Plug your PSU into the extension cord.
is the hum still there ? .

I did watch the video and that is my plan!  Thanks.  

Also - for now- the hum is gone.  I moved cords around so maybe I was just getting some interference...

But I think I’ll ground the PSU just to be sure.

Thanks for all your suggestions!