Electrical safety question - UK Vintage Radio Repair and Restoration Discussion Forum

Ancient Geek · 2nd Feb 2018, 2:13 pm

I'm currently restoring a '90s vintage professional synthesizer/keyboard made by Roland. I was rather surprised to see that it has a figure of eight mains connector with no protective earth. Most of the casing of the instrument is anodised aluminium. There is no 'double square' double insulation marking. I can understand issues surrounding ground loops and stage equipment, but were Roland sailing close to the wind with this bit of kit? Where would I stand if I wanted to sell this unit on?

Nickthedentist · 2nd Feb 2018, 2:34 pm

Roland aren't exactly a fly-by-night brand, and it's not very old either.

Assuming it has not been modified (e.g. a grey import, i.e. designed for a different area with different mains supply and safety regulations, then re-worked by an unofficial UK importer), I would leave it exactly as it is.

If you modify and sell, then you become responsible should anything go wrong.

If it's for your own use on the other hand...

Nick.

Ancient Geek · 2nd Feb 2018, 2:42 pm

Cheers, Nick. What's rather interesting is the quantity of pro-music kit that's supplied with wall-warts these days. It makes perfect sense from an economic perspective, of course. It's way cheaper to buy in an already certified adapter than to go through a costly certification process a number of times, at least once for each jurisdiction.

sortedradio · 2nd Feb 2018, 2:46 pm

It also helps keep noise caused by a power supply out of the machine.

Martin

G6Tanuki · 2nd Feb 2018, 2:55 pm

Under IEC61140 (the relevant standards document here) and its prdecessor IEC536-2 the "double square" marking is an alternative to a "Class II" labelling for such equipment: it doesn't need to carry both.

I'd trust what Roland have done and - unless you want to pay for recertification - not make any modifications!

The Philpott · 2nd Feb 2018, 3:28 pm

Just have a double check that the double square symbol hasn't been included as part of a plastic moulding somewhere, rather than being on a label as we are accustomed to seeing.

Ancient Geek · 2nd Feb 2018, 4:55 pm

Doh !

The double square symbol was hiding in plain sight on the rating label. My excuses are:

1. Its similarity to the Roland 'R' symbol made it look like decoration.
2. I need new reading glasses.
3. I only gave it a 'man look' at SWMBO would call it.

Nevertheless, I would have preferred to see some shrouding around the mains transformer, given the proximity of the exposed pins to the metal bottom plate.

dglcomp · 2nd Feb 2018, 7:17 pm

As has been said a lot of keyboards dont have earths, most Roland keyboards especially using the slightly weird rectangular 2 prong power connector that must have frustrated many a musician if lost before a gig.

And as for wall warts/in line PSU's, some keyboards (inc. the Waldorf Q and Korg M3) actually have an inline PSU mounted inside the case, not even soldered to the mainboard but using a standard barrel socket.

Another advantage of not having an internal supply is that you can have one adaptor that powers many models. The PSB-1U/230 for example powers most of their keyboards and effect units (and has done for quite a while) meaning very few different adaptors need to be made and certified meaning that you get better economies of scale and therefore lower costs.

Behringer, on the other hand, only use an external power supply when there is no chance of fitting one inside, such as in their smaller mixers, something I applaud them for.

2nd Feb 2018, 2:13 pm	#1
Ancient Geek Retired Dormant Member Join Date: Aug 2017 Location: Bristol, UK. Posts: 136	Electrical safety question I'm currently restoring a '90s vintage professional synthesizer/keyboard made by Roland. I was rather surprised to see that it has a figure of eight mains connector with no protective earth. Most of the casing of the instrument is anodised aluminium. There is no 'double square' double insulation marking. I can understand issues surrounding ground loops and stage equipment, but were Roland sailing close to the wind with this bit of kit? Where would I stand if I wanted to sell this unit on?

2nd Feb 2018, 2:34 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,844	Re: Electrical safety question Roland aren't exactly a fly-by-night brand, and it's not very old either. Assuming it has not been modified (e.g. a grey import, i.e. designed for a different area with different mains supply and safety regulations, then re-worked by an unofficial UK importer), I would leave it exactly as it is. If you modify and sell, then you become responsible should anything go wrong. If it's for your own use on the other hand... Nick.

2nd Feb 2018, 2:42 pm	#3
Ancient Geek Retired Dormant Member Join Date: Aug 2017 Location: Bristol, UK. Posts: 136	Re: Electrical safety question Cheers, Nick. What's rather interesting is the quantity of pro-music kit that's supplied with wall-warts these days. It makes perfect sense from an economic perspective, of course. It's way cheaper to buy in an already certified adapter than to go through a costly certification process a number of times, at least once for each jurisdiction.

2nd Feb 2018, 2:46 pm	#4
sortedradio Heptode Join Date: Jan 2008 Location: Sheffield, South Yorkshire, UK. Posts: 655	Re: Electrical safety question It also helps keep noise caused by a power supply out of the machine. Martin

2nd Feb 2018, 2:55 pm	#5
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: Electrical safety question Under IEC61140 (the relevant standards document here) and its prdecessor IEC536-2 the "double square" marking is an alternative to a "Class II" labelling for such equipment: it doesn't need to carry both. I'd trust what Roland have done and - unless you want to pay for recertification - not make any modifications!

2nd Feb 2018, 3:28 pm	#6
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,106	Re: Electrical safety question Just have a double check that the double square symbol hasn't been included as part of a plastic moulding somewhere, rather than being on a label as we are accustomed to seeing.

2nd Feb 2018, 4:55 pm	#7
Ancient Geek Retired Dormant Member Join Date: Aug 2017 Location: Bristol, UK. Posts: 136	Re: Electrical safety question Doh ! The double square symbol was hiding in plain sight on the rating label. My excuses are: 1. Its similarity to the Roland 'R' symbol made it look like decoration. 2. I need new reading glasses. 3. I only gave it a 'man look' at SWMBO would call it. Nevertheless, I would have preferred to see some shrouding around the mains transformer, given the proximity of the exposed pins to the metal bottom plate.

2nd Feb 2018, 7:17 pm	#8
dglcomp Heptode Join Date: Jul 2016 Location: Portland, Dorset, UK. Posts: 874	Re: Electrical safety question As has been said a lot of keyboards dont have earths, most Roland keyboards especially using the slightly weird rectangular 2 prong power connector that must have frustrated many a musician if lost before a gig. And as for wall warts/in line PSU's, some keyboards (inc. the Waldorf Q and Korg M3) actually have an inline PSU mounted inside the case, not even soldered to the mainboard but using a standard barrel socket. Another advantage of not having an internal supply is that you can have one adaptor that powers many models. The PSB-1U/230 for example powers most of their keyboards and effect units (and has done for quite a while) meaning very few different adaptors need to be made and certified meaning that you get better economies of scale and therefore lower costs. Behringer, on the other hand, only use an external power supply when there is no chance of fitting one inside, such as in their smaller mixers, something I applaud them for.