static electricity doing bad things to my keyboards

[ramthelinefeed]

(For some reason, every time I start a new thread I'm never sure I'm putting it in the right forum... this one might be better in Studio Design ... or in the Do You Seriously Want to Electrocute Yourself forum... whilst when I searched the forum for 'static' it was all about mics and guitars... but it's my keyboards are bearing the worst of it..! bear with me )

Basically: I've moved house, and have all my stuff set up in a new room.
I *think* the electrics are fine (famous last words... ) -
the letting agent had an electrical safety test done on the property before it was lit,
I tried a trusty Martindale socket tester on every socket,
and all my music stuff is plugged into the wall in the same arrangement I've used for the past decade or more, namely:
I used two wall sockets. Everything with a three-core (i.e. earthed) mains lead is starred back through some multiway-adaptors to one wall socket. And everything with a two-core lead (double-insulated) is connected back to the other.
I've also totted up all the power consumptions on a spreadsheet, and on paper they're comfortable within the 13A capacity.
And I tested it with a little in-line 'smart meter' thru-plug from my electricity supplier, which gives a live current readout (amongst other things), and I've never seen a current draw above 3A on either socket. And I always switch on at the wall first then bits of gear individually, to avoid surge inrush.

HOWEVER.
I keep getting static electric shocks when I touch various bits of gear (my Akai MPC4000! My SCI Six-trak. Even my digital Mellotron M4000D). The first two of those are earthed appliances, the last one isn't.
It doesn't feel like 240V live on the chassis (or I'd be long dead, I think), it just feels like those static shocks one sometimes gets in certain buildings when you touch a metal door handle.
Tell tale clue: there is a new springy synthetic carpet on the floor. And I only seem to get the shocks when scooting about in trainers, not if I walk about barefoot or in socks.

ANYWAYS -
the worst thing about it is that I also though my Mellotron M4000D had developed a fault. It kept spontaneously rebooting and making a nasty click in its output.
Initially this seemed to be when I waggled it's wallwart, and I though it was a dodgy wallwart. Although it seemed to be more mechanical movement of the 2.1 dc barrel connector in the machine's socket that did it, when I touched it with my fingers...

...but then the next day, it barefeet, I couldn't reproduce this reboot behaviour at all! The wallwart inlet seemed completely sound.

So: my question is: am I giving my mellotron static shocks? I mean, would that make the electronics blip and reboot? (the M4000D is basically a hardware ROMpler). Does that sound plausible?
Am worried I might just fry some ICs inside it... or particularly on older synths (like the Sixtrak, which has 35 years old Zilog Z80 CPU inside).

Is there something homebrew I could do to guard against ESD on my keyboard rigs? (Like those little wrist straps you used to be able to get in Maplin, and can doubtless now get on Amazon)... or should I call an electrician before I die?
(I found it counter intuitive that an earth chassis of an MPC4000 or SixTrak could give me a static shock... but then I thought it did make sense, cos I'd built up a charge on my body, and it was precisely because those chassis we earthed that it was discharging painfully through my fingers and through the chassis when I touched them?)

[Drew Stephenson]

Sounds very like the situation I used to have at work, I eventually pinned it down to one particular pair of shoes. The static discharges there were sometimes enough to crash either my laptop or the Mac, and more than enough to really hurt sometimes!
Possibly some kind of trailing earth cable to attach to yourself when you enter the room?
Or a big rug of a different material to the current carpet?

[Folderol]

Sounds exactly what I'd expect from a modern synthetic carpet, especially if the atmosphere is very dry too. You might do a bit better wearing leather- soled moccasins . Also, if the room is very dry, try putting a bowl of water in a corner somewhere (where it won't get kicked). A full-fat humidifier might be overkill.

I know you can get anti-static carpet treatments, but have no experience of them.

[Hugh Robjohns]

You've identified the cause: synthetic carpet and trainers generating static voltages on yourself, being discharged when touching earthed metalwork.

And yes, static surges can definitely upset microprocessor-based systems. (they can actually cause permanent damage in some cases)

And no, you don't need the services of an electrician.

The solution is to avoid building the static charge in the first place, and/or discharging yourself before touching the keyboards.

An ESD bracelet (or anklet) would obviously take care of the discharging. But you might not think that's a practical option. Alternatively, you could make a grounded (metal) wrist wrest that you get into the habit of touching regularly.

But Drew's suggestion of common-synthetic) mat over the carpet is probably the more pragmatic option. You can even buy special purpose-designed grounding mats like these:

https://www.groundology.co.uk/earthing/grounding-mats

[ramthelinefeed]

Thanks all. I think honestly I'll just take my trainers off! It's much simpler

[Martin Walker]

If you take your trainers, just make sure you're not wearing nylon socks, as the problem might get even worse (I know from experience!)

Go for socks with a high percentage of natural fibres.

Martin

[Arpangel]

I had this problem at one point in my old flat, I was wearing shoes with plastic soles, on synthetic carpets, not good.
I just didn’t wear any shoes or socks in my studio, just bare feet, problem solved.

[Dave B]

Zukan keeps warning everyone about wearing Crocs around gear, but everyone just assumes he is a fashion nazi. Not so - he is in fact trying to save our synths!

[ramthelinefeed]

https://www.groundology.co.uk/earthing/grounding-mats

I note they sell 'earthing rods' for a mere £22 quid.
(Scroll down on https://www.groundology.co.uk/earthing/accessories )

We seem to be getting into Russ Andrews territory here But for people with a garden, would this be a cheap and useful way to lower the resistance to ground of your mains earth (instead of spending a fortune having your house rewired)? Would it do beneficial things to your audio? More than once I have read in Sound on Sound from consultants who design studios that one of the most important things, asides from acoustics, is getting the lowest number of ohms you can on your ground path.
Or does sticking this in your back yard just risk acting like an aerial and sucking up electrical muck from all around?

[Hugh Robjohns]

A lot of the stuff on the Groundology site is very definitely in Russ Andrews terrority -- but although the prices are silly, they aren't quite in the same stratopheric league!

But 'Earthing Recovery Bag'? Really?

But having said that, they do have some very useful products that I've not found anywhere else and which offer very convenient and safe solutions to those not blessed with the appropriate DIY skills and competences...

On a related matter, I have visited the electronics production lines at the Calrec factory in Hebden many times, and everyone working and visiting there has to wear a 'grounding footstrap' to make sure there is no static energy building up which could easily damage the microprocessors and other components and boards. This is pretty standard in high-tech electronic manufacturing facilities. These straps are conductive plastic strips that you slip under your heel and around underneath the heel of the show, and it simply drains off any static to the conductive flooring. Obviously, factories go through these things in their hundreds every week and they cost pennies each when bought in bulk...

The same things are being sold on the Groundology site at £25 a pair! Now that's how you get rich...

[The Elf]

Zukan keeps warning everyone about wearing Crocs around gear, but everyone just assumes he is a fashion nazi. Not so - he is in fact trying to save our synths!

No, he just has this 'foot thing' going on at the moment. I regret sending him the photos...

[Folderol]

But for people with a garden, would this be a cheap and useful way to lower the resistance to ground of your mains earth (instead of spending a fortune having your house rewired)? Would it do beneficial things to your audio? More than once I have read in Sound on Sound from consultants who design studios that one of the most important things, asides from acoustics, is getting the lowest number of ohms you can on your ground path.
Or does sticking this in your back yard just risk acting like an aerial and sucking up electrical muck from all around?

Don't do it!

You should never connect two grounds with different earth sources. There is no such thing as 'Earth' potential it can vary a surprising amount over relatively short distances. At best you are likely to get obscure ground loop issues. At worst you could set your house on fire - I'm not kidding! There may only be a few volts difference, but the source impedance is likely to be very low, so possibly resulting in massive currents.

[ManFromGlass]

I have a similar carpet. Two things fixed it for me.
- I spray the inside of the specific shoes with an anti static spray, the laundry stuff, works for awhile.

- I bought a cheap Amazon humidity meter and a humidifier and keep the humidity to at least 40%. 40 to 60 is supposedly the best range for humans. Warm air holds more humidity than cold.

I thought a pot of water on the woodstove would do the trick but according to internet science not enough is absorbed into the air to do much. My humidity meter concurs.

The thing that really hurts is riding in a car with cloth seats wearing those shoes and then stepping onto the ground. Big toe and hand touching the door opener - painful shock! Yowza!

[Hugh Robjohns]

I note they sell 'earthing rods' for a mere £22 quid...

They are 'toy' rods, and with only a 2mm wire connection not exactly safe either! They state they are for use in older premises that still lack a properly grounded incoming main feeds, but you won't find a qualified electrician who would go anywhere near the things! There are much better and safer solutions.

More than once I have read in Sound on Sound from consultants who design studios that one of the most important things, asides from acoustics, is getting the lowest number of ohms you can on your ground path.

Yes, it is, but there's the right way to do it, and the wrong way -- as Folderol has pointed out if you get it wrong it could be very nasty indeed!

Professionally designed studios may well have their own local grounding arrangement with rods or, more likely, underground meshes. But they won't (usually) be connected to the incoming mains ground -- they are kept entirely separate as a dedicated 'Technical Earth'.

[ramthelinefeed]

Don't do it!

You should never connect two grounds with different earth sources. There is no such thing as 'Earth' potential it can vary a surprising amount over relatively short distances. At best you are likely to get obscure ground loop issues. At worst you could set your house on fire - I'm not kidding! There may only be a few volts difference, but the source impedance is likely to be very low, so possibly resulting in massive currents.

This sounds like wise advice and reminds me of the time there was a 10A (srsly!) ground loop current between my NTL cable feed and my ring main, manifesting itself as a hideous mains hum when plugging the set top box into my hi-fi amp.
Took about a year of trying to explain to NTL Customer Support what a earth loop was before they finally sent me a little isolator thing for my cable feed.