Weird minor shock from turntable

[kalowski]

Here's a weird one - paging Busby!!

I sometimes get a shock from my turntable tonearm. Very specifically the pointed "arm" you might use to position the tonearm.
I don't think it's a static electricity shock, but I guess that means something more dangerous. It's not a powerful shock (like the time I pushed a broken plug into a wall socket and nearly blew an arm off) but it's uncomfortable and worrying.
Although it's also mild enough for me to sometimes think I'm imagining things.
I attached the earth connection to my preamp as expected when I got it in March, and there's nothing different about the set up, other than the power being off for a week whilst I was on holiday.
I don't know what else to check, but nor do I know who I'd call for help. An electrician?
Any advice is welcome.

[Zetetic]

Do you have a multimeter?

[Echo Valley 2-6809]

Do you have a multimeter?

[touchingcloth]

Do you have a multimeter?

No, I hardly knew her.


As in, I knew her. Hardly.

[idunnosomename]

does sound like some significant charge is earthing through you via the metal arm. anyone who works on personal electronics can sort it out. my guitar was feeding back through itself when you touched the metal pickup casings, so I got a guitar man to rewire it for like £35.

[kalowski]

does sound like some significant charge is earthing through you via the metal arm. anyone who works on personal electronics can sort it out. my guitar was feeding back through itself when you touched the metal pickup casings, so I got a guitar man to rewire it for like £35.

It's only four months old. I wonder how this has happened?
I don't have a multimeter (grandad) but had considered getting one.

[WhoMe]

May be worth asking over on vinylengine or audiokarma forum, there are some very experienced heads knocking around

[Jasha]

Have you tried moving the arm with wet hands whilst wearing rubber boots?

[kalowski]

Here's why it's odd. Everything is plugged in as normal, I've touched the end as usual but no shock.
But literally nothing is different from yesterday.

Anyway, good advice about audiokarma, will try them.

[JesusAndYourBush]

I used to occasionally feel a very minor shock when I unplugged the audio leads that connect my pc to my hifi and replugged them into another socket (normally it's set for listening but when I'm transferring some old tapes I obviously have to change the position of the leads.)  Whatever it was it's not done it for years, it might even have been the previous pc not the current one.

Here's why it's odd. Everything is plugged in as normal, I've touched the end as usual but no shock.
But literally nothing is different from yesterday.

That was my experience too.  Usually, nothing.  Just occasionally - minor shock.

[Flouncer]

SOUNDS LIKE A GROUNDING ISSUE MATE, HAVE YOU TRIED SETTING ALL YOUR GEAR UP IN A FARADAY CAGE?

[badaids]

Dont touch me
Cos I'm electric
And if you touch me
You'll get
Shocked
Shocked
Shocked

[touchingcloth]

Here's why it's odd. Everything is plugged in as normal, I've touched the end as usual but no shock.
But literally nothing is different from yesterday.

Anyway, good advice about audiokarma, will try them.

My laptop (aluminium chassis) gives me very minor tingly buzzes sometimes. It's a common issue from googling it, and grounding of the sockets that the laptop is plugged into seems to be the common culprit.

It's not as simple with a record player as a laptop, but can you try moving it round different sockets in the house to see if some make it buzz and others don't? With my laptop it's only certain sockets, and there's one socket that only ever caused it if a particular appliance was plugged in in another room of the house.

I've had an electrician check the wiring in the house, and people online seem to suggest that it's not a big deal, but it's definitely going to cause my death one day.

[Goldentony]

if you were listening to total shit it might be a warning off the device itself

[St_Eddie]

I've touched the end as usual

I bet you have, you dirty old bollocks.

[Zetetic]

My laptop (aluminium chassis) gives me very minor tingly buzzes sometimes. It's a common issue from googling it, and grounding of the sockets that the laptop is plugged into seems to be the common culprit.

The reason I asked about the multimeter, because it's using one of these that I proved that the pain I sometimes got from brushing the underside of my work laptop with my hand was down to the screws having 40V difference to earth.

(I'd thought it might just be trapping hairs or something.)

[Jittlebags]

Probably static as you've got rubber belts transferring charges around, a bit like a van de Graff generator.

[Blumf]

Probably static as you've got rubber belts transferring charges around, a bit like a van de Graff generator.

So avoid listening in houses with no doors.

[Goldentony]

knew it was those titheads

[buzby]

Here's a weird one - paging Busby!!

I sometimes get a shock from my turntable tonearm. Very specifically the pointed "arm" you might use to position the tonearm.
I don't think it's a static electricity shock, but I guess that means something more dangerous. It's not a powerful shock (like the time I pushed a broken plug into a wall socket and nearly blew an arm off) but it's uncomfortable and worrying.
Although it's also mild enough for me to sometimes think I'm imagining things.
I attached the earth connection to my preamp as expected when I got it in March, and there's nothing different about the set up, other than the power being off for a week whilst I was on holiday.
I don't know what else to check, but nor do I know who I'd call for help. An electrician?
Any advice is welcome.

What turntable is it? Does it have it's own earth connection, or is it DC powered (via an external adapter/PSU) or if it has a mians lead, is it double insulated (i.e. it has no connection to the earth pin in the plug)?

There are two types of ground in audio gear - audio ground, the 0V reference for the AC audio signal, which is what usually carried by the outer ring of the RCA connector and so via the shield in each leg of the stereo cable, and chassis ground from the power supply, which is usually connected to mains earth (on devices that aren't double insulated). Some amps tie the chassis and audio grounds together, some don't as interfence on the earth from other earthed devices in the home can then be carried over into the audio circuit.

On the tunrtable, the audio ground is carried by the RCA cables into the tonearm and then to the cartridge via 2 of the 4 thin unshielded wires. Because they are unshielded, these can pick up 'hum' from other mains powered gear nearby, so the earthing point is provided to connect the chassis ground from the preamp to the tonearm to allow it to act as a shield.

The first thing I'd look at is the preamp's earthing arrangement. Is there continuity from the earth pin in the plug to the chassis grounding point where the turntable earth connects? If not then you have got a 'floating earth', which may be why you are getting shocks, especially if you are in contact with something that's actually connected to earth (if it's a valve preamp then there is a considerable risk of high voltages there too). If there is continuity between the earth pin and chassis, I'd then look to see if the earth in the socket is actually connected (you would either need a sorcket tester plug or powering the ring main off at the fusebox before taking the socket of to have a look, or an electrician). If it's connected to the socket via a socket strip extension lead, check that has earth continiuty first.

To check for continuity, you either need a cheap multimeter or a continuity tester(basically a bulb or LED  and a battery with a  probe on one side and a lead with a croc clip on the other - connect the croc clip on one end (the earth pin on the plug, in this instance) and touch the probe on the grounding point on the preamp. The bulb or LED will light if the grounding point is connected to the earth pin on the plug, as the cicrcuit between the bulb and battery will be completed.

[kalowski]

It's a Pro-Ject Debut Carbon DC, powered by a 12V DC adapter, as is the pre amp. I'll get a multimeter and check continuity, but as I said it's now stopped so perhaps it was static after all.

Thanks everyone.

K.

[buzby]

It's a Pro-Ject Debut Carbon DC, powered by a 12V DC adapter, as is the pre amp. I'll get a multimeter and check continuity, but as I said it's now stopped so perhaps it was static after all.

Thanks everyone.

K.

Ah, it's most likely static then -  the bolded bit above is probably why. If both ends are powered by DC adapters (i.e. double insulated) there there is probably no connection to the house earth at all (unless it's via the power amp, in which case it would be via the ground side of the RCA connectors between the preamp and power amp). The preamp probably has it's 'grounding point' bonded to it's audio ground as there is no chassis ground. The static is building  up by playing records (especially in hot weather), and if there is no connection to the house earth for it to dissipate it will find it's way to earth through you.

[kalowski]

Just got a fuckwad of a shock there, convinced it is static now, but I just can't seem to earth myself in any way.

[Phoenix Lazarus]

Thought this would be about Jimmy Savile.

[Goldentony]

just get a big fucking electric shock every time you play a record, cant think of any other way about this

[Jittlebags]

Just got a fuckwad of a shock there, convinced it is static now, but I just can't seem to earth myself in any way.

If it's static, earthing yourself is not the solution. That makes it worse as you are providing a path to ground. Your best bet it to insulate yourself from earth. Maybe some cork soled shoes, and a rubber suit.

[thenoise]

Have you tried listening to music using your phone rather than wheeling your gramophone out like it's the 1930s?

[kalowski]

Maybe some cork soled shoes, and a rubber suit.

My wife said "Never again" the last time.

[NoSleep]

Just got a fuckwad of a shock there, convinced it is static now, but I just can't seem to earth myself in any way.

Put a rubber sleeve or some insulation tape over the bit you have to touch.

[buzby]

Just got a fuckwad of a shock there, convinced it is static now, but I just can't seem to earth myself in any way.

If nothing in your system has a chassis ground that's connected to Earth, then as Jittlebags says every time you touch it you are providing the route to Earth for the static.

One thing you can do is take a 3 pin plug, remove the Live and Neutral pins (you don't have to, but it's safer to take them out) so there's just the Earth pin left, and run a wire from the earth pin to the preamp grounding point. If you plug it into a socket, it will then link the preamp chassis ground (and therefore the turntable) to Earth, so static will no longer build up.

If any other piece of your gear is earthed, then this runs the risk of creating an Earth Loop (which you would hear as a loud 50hz hum when the preamp & amp are turned on), but you have already said that the deck & preamp are DC powered, and if the power amp is earthed it's doesn't sound like it's connected through to the preamp.

Has the power amp got a 'Float' or 'Ground Lift' switch on the back? Some of them do. This disconnects the chassis ground from the Earth (if it has one) as a means of preventing earth loops. However, if the preamp or turntable do not have an Earth connection either then it means the whole system will have a floating ground, and there's nowhere for the static to go.