Accuphase voltage conversion


I have a Japanese market Accuphase E-370 for which I plan to use an external voltage converter for 120v.    Looking inside this Integrated, it no longer appears to have the jumpers which allowed easy voltage conversion.    Are all the new Accuphase products similar?     Does anyone know how to change the voltage internally?   Thanks 
pip555
I assume you must replace transformer. "Authorized" dealers will charge arm/leg for it.
pip-

consult Accuphase for the proper info on this matter.
Keep me posted & Happy Listening!
Bear in mind that local Accuphase distributor won’t be very happy knowing that you have Japanese unit. By their terms it’s "Unauthorized" and they will simply refuse to provide service.
Contact Japanese service provider preferably via Japanese website.
Tell you’ve moved to USA using Japanese and not English.
The other simpler way is to wire 240V dedicated line out of the distribution box. Thus no internal mods needed.

If you have no switches or fuses to change the mains voltage all is not lost.

It all depends if the mains transformer has the number of wires on the "primary side" of it to be able to be reconfigured for different mains voltages, you need a tech to look and see if it has. If so it can be as small as a 15min job.

Cheers George

Thanks for all the replies.  From what I have read on other forums, the Accuphase transformer is multi-tap (therefore multi voltage), so in theory, all one should have to do is rearrange the transformer wires.  All I require is a photo, or a schematic of someone who has a 120v version.  

When I purchased this unit, I knew that being from the gray market, I would not have access to service or assistance from Accuphase.    I don't mind using a step down transformer, but I am curious how to convert this unit internally.    


There are certain logical ways to examine which unused taps should replace ones already currently connected. 
Often on PCB you can spot the input AC voltage printed than measure voltage accross the unused taps so it's the desirable one to be connected.
For safety I'd disconnect power transformer and run tests with 220V than run tests with 110V so to find matching unused taps. The color code on output taps of power transformer can often give you some tips, but to be sure measurements can give you precise picture of your project.

pip555 OP
Thanks for all the replies. From what I have read on other forums, the Accuphase transformer is multi-tap (therefore multi voltage), so in theory, all one should have to do is rearrange the transformer wires. All I require is a photo, or a schematic of someone who has a 120v version.

When I purchased this unit, I knew that being from the gray market, I would not have access to service or assistance from Accuphase. I don’t mind using a step down transformer, but I am curious how to convert this unit internally.



Pip555 this is a very dangerous way to go about it to be told how to do it..

If you don’t know how to do it "by measuring the primary windings with an ohm meter", to find out which way to wire it up. Please give it to a qualified tech who does know and will do it this way, as he won’t go by just being told, he’ll measure twice adjust once. Just like a good carpenter, who measures twice cuts once.

As not only can you blow the amp, but also yourself in changing things in this area..


Cheers George


George, 
What is difference between qualified tech and unqualified? Is there licensing for working with electronics? I doubt it. You get lisence of electrician, but for electronics repair you don't  need even that. As to safety, there's plenty of information on how not to get zapped.

All I require is a photo, or a schematic of someone who has a 120v version.


What I’m saying if this question needed to be asked, and one doesn’t know how to do it oneself using a DMM. Then it would be much safer to get a electronics technician to do it.

As if there are multiple primary wires for different mains voltage operation which it sounds like there is, depending on the export country they can even have different colours. And there can be half a dozen different ways to wire it up.

The safest way is to measure using DMM all the static impedance of each of the
primary windings, so one can get the series or parallel connection or what wires not to use for the mains input voltage required


Is there licensing for working with electronics?

Of course there is, especially on the mains side if one need to have trust in a persons ability.

You get licence of electrician

Electricians I know, would not have much of an idea how to do this, they might have a go but confidence would be lacking. An electronic technician however would know how.

Just look at the amount of wires here on the transformer on the primary side of things, this transformer may be able to serve 100v, 110-120 or 230-240v mains, and there’s what looks to be a resistor involved, which could also be a thermistor. (seven possible connections)

http://www.hifido.co.jp/photo/07/108/10895/e.jpg


Cheers George

hmmm... 
I started changing tubes in my mono console system when I was 8. Than started repairing TV not too long after.
Never bothered getting lisence of electronic tech and still prefer to repair my own electronics as a matter of fact without help of lisenced tech.
License is probably something to do more with money not with actual skill or trust. 
Number of possible connection dictates to use logic to identify the right terminals more than knowledge of electronics or electro-magnetics. It means that there are color codes to ID either by measurements or by asking crowd or by asking manufacturer directly in Japan who will most-probably share this information. 
As DIY tech I've been able to receive or download lots of circuit diagrams that carry bunch of usefull information about voltage across certain terminals and wire colors. It might be harder to get diagrams for later models, but if available for earlier models the color code can very possibly match the newer model.
pip555,
Open the amp, see if you can find the  broad https://www.facebook.com/media/set/?set=a.401024800009547.1073741833.266965016748860&type=3