USA to UK voltage step down converter

[vinorange]

Morning Basschatters

I’ve taken a punt on a USA voltage amp and need a suitable step down converter. The amp runs 600w at 4 ohms and 900w peak I think. I’ve read that I need double the wattage capacity so a 3kw transformer would do but can anyone recommend one that would be suitable please and advise of that sort of capacity is right?

Thanks

[Hellzero]

Hi Vin,

The output power and consumption power are two different things. You need to use the consumption power which will be lower. 😉

[Hellzero]

What amp did you buy ?

[vinorange]

Just now, Hellzero said:

What amp did you buy ?

Eden WTP600. I have a bad Eden addiction......

[Hellzero]

No need for a step down converter as it's a multitap power transformer inside. A qualified tech will make the adaptation in 2 minutes (it's only a soldering affair).

[vinorange]

Really? That's even better news than I could imagine!

Thanks Tony.

[vinorange]

45 minutes ago, Hellzero said:

No need for a step down converter as it's a multitap power transformer inside. A qualified tech will make the adaptation in 2 minutes (it's only a soldering affair).

The seller says in the ad that the PSU is not multi country. Has he got it wrong?

[Hellzero]

It's an inside mod, not an outside switch.

[vinorange]

39 minutes ago, Hellzero said:

It's an inside mod, not an outside switch.

He reckoned he’d been in touch with Marshall USA and they’d said it couldn’t be modified but it wouldn’t surprise me if they didn’t know what they were taking about.....

[Stub Mandrel]

If not, you can usually pick up second hand building site step down/isolation transformers for relatively cheap prices.

This one is £30

https://www.ebay.co.uk/itm/333942668997?hash=item4dc088bec5:g:TbsAAOSwZCVgZead

[machinehead]

A quick look inside at the power transformer will tell you if the tappings can be changed to suit a different voltage.  It's pretty simple to understand.  Check the primary side of the transformer (the input side) for tapping options. If you're not sure, post some pics and a description of what it says on the transformer and me or someone else will be able to advise.

If the tappings can be changed, it's a simple job to carry out.  And if the amp was designed for this, it will also be designed to work on both the USA supply frequency of 60Hz and 50HZ European supply frequency.  In any case, using a device designed for 60Hz on a 50Hz supply is less problematic than using a 50Hz device on a 60Hz supply. (in the latter case you can reduce the supply voltage slightly to compensate for the frequency change.)

Have a quick look and let us know.

Frank.

[vinorange]

22 minutes ago, Stub Mandrel said:

If not, you can usually pick up second hand building site step down/isolation transformers for relatively cheap prices.

This one is £30

https://www.ebay.co.uk/itm/333942668997?hash=item4dc088bec5:g:TbsAAOSwZCVgZead

Thanks for the tip. I’d seen ex site transformers but wasn’t sure they’d be ok. Ta

[vinorange]

8 minutes ago, machinehead said:

A quick look inside at the power transformer will tell you if the tappings can be changed to suit a different voltage.  It's pretty simple to understand.  Check the primary side of the transformer (the input side) for tapping options. If you're not sure, post some pics and a description of what it says on the transformer and me or someone else will be able to advise.

If the tappings can be changed, it's a simple job to carry out.  And if the amp was designed for this, it will also be designed to work on both the USA supply frequency of 60Hz and 50HZ European supply frequency.  In any case, using a device designed for 60Hz on a 50Hz supply is less problematic than using a 50Hz device on a 60Hz supply. (in the latter case you can reduce the supply voltage slightly to compensate for the frequency change.)

Have a quick look and let us know.

Frank.

Thank you Frank. I’ll open it up when it arrives and post some pics. Thanks very much for your advice.

[vinorange]

I just got through to the service department at Marshall who said that Eden made different transformers (not multi tap) for different countries so I'd need either a UK voltage transformer or a step down transformer.

Still haven't got it to have a peep yet though......

[Hellzero]

Better open it and take a look inside yourself...

[vinorange]

Here's a picture or two of my innards....

[PaulThePlug]

Toroidal out if RS Components?... https://uk.rs-online.com/web/c/power-supplies-transformers/transformers/toroidal-transformers/

63.2 - 0 - 63.2

 

[vinorange]

19 minutes ago, PaulThePlug said:

Toroidal out if RS Components?... https://uk.rs-online.com/web/c/power-supplies-transformers/transformers/toroidal-transformers/

63.2 - 0 - 63.2

 

Thanks for the link and advice.

Which one from RS though? There's 8 pages of toroidal xformers.....

Edited June 8, 2021 by vinorange

[vinorange]

That's what she says....

[Matt P]

it looks like there are 3 sets of windings on that transformer, 

63.2v-0-63.2v        0-11v           and  17v-0-17v

if that's the case then RS won't be much help, that's a fairly unique transformer so you will either need to have it wound to order or find the correct UK eden one.

 

Matt

[machinehead]

I think Matt is right.  The transformer in my Thunderfunk is custom made too and is probably the only component that isn't a standard piece.

That transformer is made by Webb in Taiwan.  There is an enquiry page.  I'm not sure how successful an enquiry would be though.  A separate 230/120 volt transformer might be the easiest way around this.

Webb Ltd (globalsources.com)

Frank.

[Matt P]

From experience i think a separate step down transformer is the easiest option if Eden/Marshall cannot sell you the correct transformer.

I spent some time last year trying to buy a replacement for a blown transformer for my Cyrus Hifi amp, (2 sets of secondary windings, toroidal transformer), Cyrus didn't have any left and i spent a couple of days hunting for the correct spec, in the end i bought a new amp instead.

 

if you get a step down transformer that is housed in a box you could mount the whole lot in a rack case and that way you'd never turn up at the gig without the step down transformer.

Matt

[vinorange]

2 hours ago, Matt P said:

From experience i think a separate step down transformer is the easiest option if Eden/Marshall cannot sell you the correct transformer.

I spent some time last year trying to buy a replacement for a blown transformer for my Cyrus Hifi amp, (2 sets of secondary windings, toroidal transformer), Cyrus didn't have any left and i spent a couple of days hunting for the correct spec, in the end i bought a new amp instead.

 

if you get a step down transformer that is housed in a box you could mount the whole lot in a rack case and that way you'd never turn up at the gig without the step down transformer.

Matt

Thanks Matt. 

 I'm beginning to think that is best. Just waiting on Eden who are now owned by Gear4Music to get back to me to see if there's any UK stock and then it'll be a step down transformer. To be honest it'll be easier and cheaper that way as, although handy, I'd not trust myself wiring in a replacement xformer.

Cheers. Vin

[fleabag]

Oops

Edited June 9, 2021 by fleabag

[Matt P]

Have you asked marshall as well? They might have some transformers on the shelf from when they owned eden