Power amp 220v would it work in UK?

[rag987]

I am looking at a power amp on eBay, it is rated at 220v (European specification?) rather than the 230v nominal rating in the UK. Would it be a OK to use?

From my understanding:

• EU harmonised voltage is 230v
  
• UK remains 240v grid with a -10 +6 range after EU harmonisation - i.e. 216 to 254v
• EU remains 220v grid with a -6 +10 range - i.e. 207 to 242v

Also I have a meter in my house that shows voltage as 239.6v this morning. It generally sits around the 240mark, though I have no idea on how accurate it is.

If the amp's voltage tolerance is +- 10% that would give a safe operating range of 198 to 242v. So close to the limit at the top - what happens if the voltage delivered is above 242v?

 

[Mike P]

The answer is to run it off an external bucking transformer that has been specified to knock 20vac off the mains voltage. I've done just this on several occasions.

You can then relax knowing that the amp is working within its designed operating conditions.

 

[Dan K]

https://pinkfishmedia.net/forum/threads/bucking-transformer-advice-please.253238/page-2#post-4527359

Working very well

 

[rag987]

Thanks both - learnt something here. Let me look into these, the amp is rated at peak 1kW so presumably the transformer would need to exceed that rating? Though I expect it would normally run 50-100W range.

 

[Arkless Electronics]

Whether or not a 220V amp will be OK on 240V depends a great deal on what type of amp it is and, more difficult to ascertain, the nature of the internal circuitry.

 

[rag987]

Whether or not a 220V amp will be OK on 240V depends a great deal on what type of amp it is and, more difficult to ascertain, the nature of the internal circuitry.

Bryston 4B3

 

[Arkless Electronics]

It may well have internal taps for 240V.

 

[chartz]

I have loads of 220 V old gear. Now we have 235 V and they work just equally fine. Just expect more noise from toroidals especially.
Obviously when a 240 V UK tap is available I use that.

 

[Mike P]

It may well have internal taps for 240V.

Yes, I may have been a bit hasty there with my suggestion of a bucking transformer. Obviously check this first!

 

[CJ14]

I wind my transformer now and when I did Inca Tech with 20% extra wire on the primary, just to help stop audible hum, you could use a auto transformer, there are some with electronic to select the tap voltage for you.
So look for Electronic Controlled Auto Transformers, normally done for large industrial device with solid state relay, beware if the SSR is a back to back thyristor type it will cause noise, so filter, but the good news is that Root2 do a silent SSR based on my patent design.
https://www.root2.ltd.uk/

https://data.epo.org/publication-server/document?iDocId=2073117&iFormat=2

https://worldwide.espacenet.com/sea...ne&compact=false&DB=EPODOC&query=colin+wonfor

 

[rag987]

This talk of taps is beyond my practical knowledge, so if I go ahead would have to be done by someone in the know. Do these images help in determining if this is technically available with this amp?

I also found a schematic of the older 4BSST on the web - any use?

 

[Operajulian]

Bryston 4B3

Bryston are based in Peterborough, Canada. Not far from me.
They have 120v versions so I would expect there are multiple taps on the transformers.
Why not contact them and ask ?
https://bryston.com/#contact-form

They have a very good reputation over here.

If you are in UK - there are a number of dealers.
See this:-
https://bryston.co.uk/dealers/default.php

 

[Arkless Electronics]

This talk of taps is beyond my practical knowledge, so if I go ahead would have to be done by someone in the know. Do these images help in determining if this is technically available with this amp?

I also found a schematic of the older 4BSST on the web - any use?

That one has taps for 100V, 120V and 230V but not 240V

 

[wacko]

That one has taps for 100V, 120V and 230V but not 240V

Perhaps because it doesn't need them as it will work fine on 240v ? Anyway just ask Bryston as mentioned above.

 

[rag987]

Thanks all for your input - I will contact Bryston and see what they say.

 

[Beobloke]

As it’s a Bryston it should be absolutely fine.

If it was some dodgy cheap Chinese thing, I would be more concerned!

 

[James]

Thanks both - learnt something here. Let me look into these, the amp is rated at peak 1kW so presumably the transformer would need to exceed that rating? Though I expect it would normally run 50-100W range.

No, that's not how bucking transformers work - according to Rod Elliot, where he says ...

The bucking transformer works by placing the secondary of a (relatively small) transformer in series with the mains, but wired out-of-phase so the voltage is 'bucked' or reduced by subtraction. Only the secondary winding needs to carry the full mains current. This means that for 240V to 220V we need to 'buck' 20V at 10A - a maximum of 200VA. Likewise, for 120V to 110V, we only need to buck 10V at 20A ... also 200VA.

 

[Mike P]

No, that's not how bucking transformers work - according to Rod Elliot, where he says ...

Indeed. A bucking transformer can be much smaller and cheaper, which is a key benefit of doing it that way.