I'd look at which way it goes inside, some dual voltage things do a 2:1 step down for 240, some do a 2:1 step up for 110-120... it would be a bit silly if you went to "lengths" to step the input down to 110 only to have it multiply it up to 220-240 again.

Having said that, in this part of the world, you find some of the better convertors in the luggage stores. Also a lot of overpriced trash too, but you will find some choice.

Manual of the thing sort of suggests it has a full range PSU in it. If you are willing to open up the thing and have a look inside, it shouldn't be hard to determine if it really does have a PSU like that. I couldn't find any good photos but what matters is the voltage rating on primary side bulk capacitor. If it is 400V it is having a full range PSU and there won't be need for any stepdown converter.

As far as these converter goes, it should be an autotransformer based thing rather than anything active. They are very much foolproof and for a low power device like this MIDI module, pretty much anything should do...

EDIT: I found a photo in a japanese blog that clearly shows that capacitor to be 400V :

https://inqra-yoch.hatenablog.jp/entry/20111225/1324797864

See also : Questions on running/testing a Japanese 100v sound module (Roland SC-D70) on a North American 120V power grid .

I'm almost positive the SC-D70 is universal. Used it in Aus and US both with no conversion, just a different cable due to the plugs being different.

Well thanks for your help everyone, I'm now the proud owner of a paperweight.

After half an hour of diagnostics, I'm confident the fuse has blown (and hey, it's soldered in so I can't fix it myself!) Obviously no way to know if anything else is fried till that's repaired, but at least I have a chance.

So is there anyone who can answer my original question? Because I imagine I'm going to want to give the repair shop an appropriate transformer.

The sc55 sc88 and jv1080 all have a component (a universal transformer I think is called?) inside where you can easily convert to us voltage by unsoldering and soldering one wire. It’s clearly labeled with voltages on large pins sticking out. Does the d70 have the same thing inside?

You should never plug in something meant for a different voltage into us mains power, that’s asking for it to break. Even 100 to 120 isn’t safe.

Edit: I just looked it up and there is Indeed a universal transformer inside. Just unsolder the wire running to 240 and solder it on to 120 instead.

Actually you’re going up to 240 aren’t you? Sorry I thought you were in the us. Just unsolder whatever the wire is on currently and solder it on to your voltage.

midicollector wrote on 2024-03-19, 19:15:

.....It’s clearly labeled with voltages on large pins sticking out. Does the d70 have the same thing inside?
Edit: I just looked it up and there is Indeed a universal transformer inside. Just unsolder the wire running to 240 and solder it on to 120 instead.

Please read the room, and also the thread. The SC-D70 doesn't have a "universal transformer", it has a switched mode power supply. So; no idea what picture you're looking at.

Also, if you read the two previous comments, I followed the advice in this thread (checked for a 400V input cap and then plugged it in) and IT'S ALREADY FFFFFFFFFFFFFFFFFFFFFFF DEAD.

So could you do me a solid, and if you don't have an answer to the original question of "what power transformers are worth buying in the UK", could you just Not Comment At All? Because my mood right now is a little too sour to enjoy any more wrong answers.

InTheStudy wrote on 2024-03-19, 19:28:

Please read the room, and also the thread. The SC-D70 doesn't have a "universal transformer", it has a switched mode power suppl […]
Show full quote

midicollector wrote on 2024-03-19, 19:15:

.....It’s clearly labeled with voltages on large pins sticking out. Does the d70 have the same thing inside?
Edit: I just looked it up and there is Indeed a universal transformer inside. Just unsolder the wire running to 240 and solder it on to 120 instead.

Please read the room, and also the thread. The SC-D70 doesn't have a "universal transformer", it has a switched mode power supply. So; no idea what picture you're looking at.

Also, if you read the two previous comments, I followed the advice in this thread (checked for a 400V input cap and then plugged it in) and IT'S ALREADY FFFFFFFFFFFFFFFFFFFFFFF DEAD.

So could you do me a solid, and if you don't have an answer to the original question of "what power transformers are worth buying in the UK", could you just Not Comment At All? Because my mood right now is a little too sour to enjoy any more wrong answers.

I am sorry that the fuse apparently blew in yours. Hopefully nothing else got damaged.

That being said, short of asking Roland and getting an official answer OR actually analyzing a specific PSU's design/construction, there are no absolute guarantees.

If one trusts anecdotal user experiences (my own included), at least some Japan sourced units have :
- appeared to work correctly in North America on 110/117/120V
- appeared to work correctly in North America on 220/230V

This does not imply that all Japan sourced SC-D70 (or those from North America) units can handle 240V.

I am again sorry to read that yours apparently reacted badly and hope that the unit can be brought back to life inexpensively. Additionally, while all circumstantial evidence points towards the unit having balked at being fed 240V, it is not impossible that the fuse blew due to either another reason altogether or even as a result of a component having gone out of spec/being borderline in a way that caused a failure that would normally not have occurred otherwise even at 240V .

so, am I right and there is no SC-S70 Service Manual available, at least not one that is in the public domain?

InTheStudy wrote on 2024-03-19, 19:28:

Please read the room, and also the thread.

So in case it's not obvious, my particular beef with MC is that their comment came 45 minutes after I'd already said it was dead, and consisted of information that wasn't even anecdotally correct. I assume they got confused with the D70, rather than the SC-D70 - Understandable, but if they had read the other replies they would have A: gotten the obvious clue that they were looking at the wrong thing, and B: seen the message that it was dead, and known that giving *any* answer at this point was likely to be seen as spectacularly unhelpful. I'm not apologising for reacting poorly to that and I think I showed quite spectacular restraint in the moment.

darry wrote on 2024-03-19, 21:50:

There are no absolute guarantees. Anecdotal user experiences. This does not imply that. Circumstantial evidence.

Hopefully you'll note I resisted the temptation to ask you to contribute to a replacement.

Hopefully nothing else got damaged. Hope that the unit can be brought back to life inexpensively.

I actually recorded a "funny" video clip as I powered it on for the first time, with a "VOGONS if this doesn't work you owe me a new synth" commentary, and followed by "...fine, you win."

It powered on, ran for two minutes, and blew roughly the time I powered on my PC. When I was troubleshooting, my multimeter gave a reading of 242VAC. It's not calibrated, so there's a chance it's just way off - but that would be well within the upper bound of UK spec (230 +- a bit). So it's possible turning on the PC caused a transient, or there was an unrelated small variation that took me over the 250V fuse rating. Honestly, that's the straw I'm clinging to right now. Because I can't afford to replace this if it's dead. I can barely afford to pay for the repair, since the day after I ordered this I got a £1000+ car repair bill (still waiting on parts availability - let alone the final total). And it's not like I can send it back having given it 2.5x the rated input voltage, even if this was a "something else was on the edge".

But to be clear, the reason I'm angry is because I knew this was a bad idea to start with.

So, my SC-D70 arrived today! Now, I am aware that people have successfully used these on 240V mains without any problems. I am not so brave, especially given what they're going for at the moment. So I need a step down.

It was my intention from the very beginning to run this at 100-120V through a step down converter. The only question I asked was "which is a good quality transformer brand, people in the UK?" and you, and several others, gave me unsolicited advice that talked me into taking the risk. That's your fault(s), and quite frankly it's entirely fair and reasonable for me to blame you and be angry at you for it. That said, the final decision was mine and mine alone which is why I'm not letting myself shout, or rave, or try to bully any of you into paying for it. This is my cost to pay. But it doesn't absolve you for your words, and I hope you'll all reflect on that.

I see no sign of burnt chips or burst caps. I don't have a way to do any other testing on the spot, and I'm not skilled enough to try and do anything more myself. I "know a guy" who works in a lab and has a side hobby of repairing electronics. I trust his skills and his costs are fair. If this is just the fuse, I can chalk this up to a learning experience and it won't cause me any long term harm.

If not - well - you, Spikey and Tiido have collectively ruined my week. If I've actually killed it dead, you've probably ruined the hobby for me. I guess we'll see.

mattw wrote on 2024-03-19, 22:18:

so, am I right and there is no SC-D70 Service Manual available, at least not one that is in the public domain?

Not that I've been able to locate. Nor have I been able to locate one for the other synths reported to use the same or similar PSU. Which is unfortunate.

InTheStudy wrote on 2024-03-19, 22:26:

use the same or similar PSU

hmm, too many reports from actual owners it works just fine on 220-240V and the switch-mode power supply inside is in fact universal:

Re: Seeking advice on Sound Canvas VA versus hardware (8820/D70)

Re: Seeking advice on Sound Canvas VA versus hardware (8820/D70)

and so on. So, I am staring to believe your device failed for some other reason, i.e. it would have failed within those 2 minutes of work even if you plugged it to 100V.

That is most unfortunate, I'm very sorry that this happened D:

I am up for a repair (and perhaps any necessary modification to prevent a future blowout), but shipping cost would need to get covered...

Tiido wrote on 2024-03-19, 22:38:

but shipping cost would need to get covered...

IMHO, the "Customs Clearance" will be the biggest problem.

Tiido wrote on 2024-03-19, 22:38:

I am up for a repair (and perhaps any necessary modification to prevent a future blowout), but shipping cost would need to get covered...

As I said, taking care of this locally but the offer is appreciated.

mattw wrote on 2024-03-19, 22:42:

IMHO, the "Customs Clearance" will be the biggest problem.

I am in a terrible mood already do NOT get me started on Brexit, for the love of god.

mattw wrote on 2024-03-19, 22:36:

i.e. it would have failed within those 2 minutes of work even if you plugged it to 100V.

But at least then I'd have been able to turn round to the seller and ask for a refund.

I think I will agree with mattw's thought on this, it likely was gonna fail with 100V too in this situation...

mattw wrote on 2024-03-19, 22:42:

IMHO, the "Customs Clearance" will be the biggest problem.

On the Norway side on things, I have not had any kind of problems or have had to pay anything either so far.