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Jay watts 16th November 2011 01:43 AM

Pioneer amplifier voltage selector
Hi all I was just after a bit of advice.
I have a pioneer vsx-521k amplifier and I want to change it from 110v to 240v.
I have taken the power supply out and on the board there is a spot for a switch, however the switch is not on the board and instead there is jumper wires connecting the terminals.
Does anyone know if I can re-arange the jumper wires to convert it to 240V???

Jay watts 16th November 2011 03:05 AM

1 Attachment(s)
Attachment 249607

This is a photo of the power board.
as you can see i put a jumper from the center terminal of the selector to the R/H terminal. it was originally from the center to the L/H terminal. Which was achieved by jumping j302 and 301.

Jay watts 16th November 2011 05:03 AM

Alternatively would anyone have a schematic of the power board or service manual?

Mooly 16th November 2011 08:37 AM

Your piccy appears to show just an auxilliary power supply that will be used to keep the microprocessor and remote receiver active when in standby.

So I think there is a lot more you need to check.

Does the main amplifier power supply use a normal mains transformer or does it use an SMPS type supply ? That also has to be altered for 240 vac. An SMPS type may need no adjustment (but you MUST check for sure). A linear supply certainly will need adjustment... and that may not even be possible depending on the original transformer fitted and its intended market.

I would advise caution with this as you risk writing the unit off if you get it wrong.

Jay watts 16th November 2011 09:32 PM

1 Attachment(s)
Thanks Mooly, yes there is a second transformer as seen in this photo.
One of the power inputs to this transformer comes directly from the AC lead and the other comes from the power selector terminal on the power circuit board.
With 110V input, the voltage across the centre and L/H posts of the voltage selector is 86V, and across centre and R/H is 44V.
That's the reason I thought it might be as easy as changing the jumper wire.
Attachment 249775

Jay watts 16th November 2011 10:00 PM

Hello again, is there a way to find out if it is a SMPS or Linear type transformer?

Mooly 17th November 2011 08:46 AM

That's a linear (normal PSU).

What you are looking for (and going off the picture I can't see it) is multiple primary windings to allow voltage selection. All I can see is the blue and black leads from the centre of the transformer bobbin going to what appears to be the mains input feed to the transformer. Which if that is so means its a single voltage winding. All the other wires appear to come from the outer bobbin which are the secondaries.

Equipment like this is aimed at many markets and the small auxilliary PCB does appear to have voltage selection available but that is only for that PCB which may be fitted to all variants. The main transformer looks like it is single voltage only.

What does it say on the rear panel ? Does it specify 110/130/240 etc via adjustment or not.

I think what you are measuring voltage wise is just the voltage across the different primary tappings on the small transformer.

Jay watts 17th November 2011 10:33 AM

Again thanks heaps for your help. It only has 110V written on the back.
I will buy a better quality step down transformer than the one I have, and hopefully it will work a bit better.

Mooly 18th November 2011 12:41 PM

I think that's all you can do tbh

Another long shot idea is to see if the 240 volt tranny is available as an official spares item. If you have a manual it may cover all markets and give part numbers...

airebros 29th January 2012 10:18 AM

Did you fix it?
So, I have the same problem, I am from europe and buy the av on usa, I want to change the voltage to eliminate the 500W 220 to 120 v transformer.

Did you fix it?

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