Help - Rega P2 grounding issue but only at my house...

Hi there,

I have recently purchased an Onkyo A9010, Dali Zensor 3 speakers and a Rega P2. However, I am having an issue with what at first glance is something that has been discussed on a number of occasions, but one that I think is actually different to other threads regarding Rega P2 'humming'

When my amp is set to the phono channel, there is a noticeable hum regardless of whether the TT is plugged in to the mains or not (but obviously hooked up to the phono connection). I have had it checked by two separate hifi stores (both Rega dealerships) and both indicate that there isn’t an issue.

The humming itself increases as I move my hand closer to the tonearm and even more so when I touch any part of it. This happens regardless of the floor in my house I try it on, and I have also tried it with a pre-amp hooked up to another amp. I can remove the hum, if I touch the underside of the cartridge with my finger, or if I connect some speaker cable to the ground connection to the amp and then touch the screw on the top left part of the cartridge/tonearm.

However, I have also tried it at a friend’s house and the issue is not present at all (which is what the two dealerships said). Therefore, I can only assume it is something to do with my house, but what that is, is beyond me. I thought it might be a ground loop problem, so I bought a ground loop isolator, which hasn’t helped at all apart from I now can’t remove the hum by touching the bits that previously removed the hum.

When I touch the tonearm lever, I get a clicking noise and when I move the tonearm it both increases the hum as well as giving a bit of a static/crackle noise as I move it.

Does anyone have any ideas at all? As things stand I am going to have to sell the TT I have and buy a completely different make and hope that works.

Thanks in advance

Mark

 

First, I take it you are not using a phono stage between the a9010 and the turntable? Are you going direct into the a9010? And the TT ground is going to the A9010 if you are using the phono stage there?

Then, at your friends house, is that using YOUR setup that it goes away, or is it on his P2 and setup?

There are many factors that can produce ground loop / noise issues, and careful isolation of everything is critical.

 

Thanks for the response.

At home I have connected direct to the a9010 through the phono connection and also via the non-phono connections with a pre-amp. I have also tried it via a pre-amp on another amp source (my home cinema kit). At my friend's house, I have tried it direct to a phono connection, only via a pre-amp.

 

One thing to check - I know from experience - you can chase around ground hum issues all day long, and then find out later it is a polarity issue where one of your outlets is reverse polarity. Does not even have to be the outlet that you are using.

I am not going to tell you how to check it - it is easy - but for liability, ask your (or an) electrician, search the web.... I don't want you to get zapped, then say "this guy on the Hoff told me how to do it" But consider that.

The fact that it works at your friends house and not at yours tells me there may be a ground loop issue at your house - start with polarity checks of your outlets.

Next, the P2's - there are reviews where the users fought hum issues on Rega - I have never owned one, but there are plenty here that do.

But, again, since it worked at your friends house - was the table further away from the amp at your friends house, or more isolated? Do you perhaps have another power transformer in the same power strip that is misbehaving? (Common). I have had multiple instance where a wall wart plugged in the same circuit was noisy - an optical XMAS tree with I keep up all year (it looks cool, think lava lamp), also a light I bought for my TT station. I would even start there, take everything else out of the power strip - EVEN out of other outlets as they might be on the same circuit. Maybe start with this... easy to do.

EDIT: DO you have a cheap $5 power strip? Maybe now that you have a TT, the pinnacle of finicky with ground loops, maybe it is time to consider a mid priced Furman power conditioner. Many will debate, but at the very least it is a HIGH quality power strip.

Again, the fact you have hum in one location and not in another tells me there is something about the offending location...

Other things to note, which don't sound like the problem just good to know, the other day, I was getting a hum on my Lounge and after some time going "Wtf" - then I checked the wiring on my cartridge, one was rather loose. I then cleaned the contacts on the headshell, front and back, then put new wires on it (the old ones were the cheaper silver ones) and hum gone.

Just some food for thought... don't overeat.

 

Thanks - will look in to the polarity point. I had a look online and it went over my head to be honest, so that'll need an electrician I think.

At my friend's house, the TT was extremely close to the amp. I have also tried at home isolate as much as possible so I really don't think that is the issue.

I will try disconnecting everything else in the house and see if that makes any difference.

 

Update: I have turned everything off across the house, and on the fuse box only left the circuit on that the system was set up on. Same humming issue. I then moved it to another circuit, and the same problem. This is beginning to drive me crazy...

 

My P3 hums when i touch the arm but is fine when playing records. No other humming issues. Do you know a friendly electrician? It might be the only solution. My guess is that you changed the TT the problem may well persist

 

I think you've done all the normal steps, so I agree that it's time for an electrician. I have a ground hum that I couldn't fix for a long time. Luckily it was very low and tolerable. But I checked my outlet and found that it had no ground. 1950's home, so not uncommon. I installed a new outlet with a ground tied to another newer outlet that had a ground set up all ready. Problem solved.


The things we do for good sound, haha.

 

Make sure you have everything connected to your stereo directed to ONE outlet and ground your integrated amp. If you still get a hum then I bet you need to have a ground wire installed from your cartridge to your amp. I have had that problem with both Regas I've owned. I sent both of my tonearms and had them rewired with Incognito upgrade by Brit Audio (in NC). This upgrade includes a dedicated ground wire to your cartridge which will take away your hum. It sucks to not have your TT for 2 weeks but if you have this issue you need to do this and I don't recommend doing it yourself unless you are experienced with rewiring your tonearms.

 

No accounting for the fact there seem to be a lot of instances where users have had hum issues with some model Rega TT's. I think there are a couple posts recently here on the board, and on well read review sites.... HOWEVER it does sound like something in the location where the OP is, seeing as how it works at a friends house, but just sayin'

OP - I hope you get it sorted. To add to my previous post - checking the polarity of your outlets - takes a $20 voltmeter and about 2 seconds. If what you were reading on the net went over your head you were reading the wrong sites, and probably intentionally making it sound harder than it is. Do a little more digging, many of us do it routinely. If you are not comfortable with that, no worries, COMPLETELY understood just wanted to share it is not a complex, expensive or difficult proposition for a homeowner to do.

If you do find reverse polarity, it is a simple as shutting down the mains at your house, pulling the outlet and swapping the hot and neutral wires - again, many do it routinely. If any of this scares you, which I can understand if it does - electricity scares a lot of people - then hire the electrician. Don't do anything you are not comfortable with!!

But I would keep eliminating all variables first... lots of good advice throughout the thread.

 

Thanks for the advice everyone.

I bought a socket tester today (although it doesn't check for earth neutral reverse) and it told me everything was fine. So, I think it is time to get an electrician in given it seems to be hum-free in other properties.

 

I guarantee you need the ground wire installed on your tonearm. I've been there with it. I'm not sure but you may be able to test this theory by running a wire from your amp ground to your cartridge although I didn't do that myself and someone else with more experience could maybe confirm if that is a good idea. I just don't know if there is a bad place you could touch the wire to the cartridge. However, I would def pursue this fix because I'm sure this is it more likely than your house's wiring. Its the difference in wiring between the 2 houses but the Rega hum issue is variable from person to person too.

 

If the turntable is fine elsewhere, then would this still be an appropriate step to take? If so, what are the best and/or easiest ways to do it?

The concern I have is that given it has been tested in three different properties and has been fine, then there is a more serious under-lying cause in my house.

Thanks

 

Try a different TT, hopefully one with a grounded tonearm, and see if you have same problem. If you do, then it is not the grounding of the tonearm. Also try to disconnect your cable and HDMI connections if they are connected to your stereo in any way.

 

Like I said earlier, you can try running a wire from your cartridge to the ground of your amp and see if it stops the hum. If so, you need a ground wire installed. I sent mine to Brit Audio for the Incognito wire upgrade and asked for a dedicated ground wire. My TT hums really bad without it.