voltage problem...

[seoirse2002]

Hi All,

Marantz PM80 Japanese 100V...

Allen kindly came around today and we managed to power it up with his stepdown transformer which goes to 100V,but we hadn't got the correct output fuses which immediately blew...I have ordered the correct ones 125V 5a so should be sorted soon....
My question is: Do I have to use a stepdown to the Japanese 100V as they seem hard to find or can I use a stepdown to 110/120v which seems much more common....
Provided I can get the amp working with a borrowed stepdown to 100V....should I wait to find one or use a 110V? I don't want to damage such a vintage amp....ta in advance:) and I will await the experts advice

[istari_knight]

I've used a 110v stepdown on a 100v DAC in the past without a problem.

Can you confirm which fuses you fitted that blew ? They shouldn't be blowing unless woefully underrated...

Looking at the service manual it would appear your version [100v 50/60Hz] has input voltage selection somewhere inside, can you post up a high res picture of the internals [focusing around the power supply.] We might be able to figure it out :)

http://i26.photobucket.com/albums/c129/istari_knight9/PM80_zps77d81026.png

[Ali Tait]

I'd find a 100v one myself. Using 110/120 is just like running a chinese 220v valve amp on our 240v. Might be fine, even for years, but will eventually take it's toll. Especially where more fragile vintage kit is concerned.

[Canetoad]

You could make up a bucking transformer using 115v primaries and 12 or 15v secondaries. I did a similar thing to get 220v for my Dared valve amp. Works great! :)

[Ali Tait]

Aye, that would work well.

[seoirse2002]

I've used a 110v stepdown on a 100v DAC in the past without a problem.

Can you confirm which fuses you fitted that blew ? They shouldn't be blowing unless woefully underrated...

Looking at the service manual it would appear your version [100v 50/60Hz] has input voltage selection somewhere inside, can you post up a high res picture of the internals [focusing around the power supply.] We might be able to figure it out :)

http://i26.photobucket.com/albums/c129/istari_knight9/PM80_zps77d81026.png

Hi James,
pics later on.....yes, woefully underated.... as I hadn't got any 125V 5a....I fitted 250v 100ma...I think they are for the outputs?...as 2 other original fuses in there weren't blown 250v 1A we left them in and one of them blew as well....only one didn't blow was the 8A...

[seoirse2002]

Hi James,
pics later on.....yes, woefully underated.... as I hadn't got any 125V 5a....I fitted 250v 100ma...I think they are for the outputs?...as 2 other original fuses in there weren't blown 250v 1A we left them in and one of them blew as well....only one didn't blow was the 8A...

These pics ok??

http://theartofsound.net/forum/attachment.php?attachmentid=10501&d=1378122460

http://theartofsound.net/forum/attachment.php?attachmentid=10500&d=13781
22448

http://theartofsound.net/forum/attachment.php?attachmentid=10499&d=1378122435

http://theartofsound.net/forum/attachment.php?attachmentid=10498&d=1378122423
http://theartofsound.net/forum/attachment.php?attachmentid=10497&d=1378122408

[Audio Al]

George

Have a look at this one

http://www.airlinktransformers.com/voltage_convertors/japanese_100V_voltage_converters/JA0050/

may do the job

£21 ;)

or these

http://www.airlinktransformers.com/voltage_convertors/japanese_100V_voltage_converters/

[seoirse2002]

Ta for the links Al, and many thanks for the help yesterday,
Ill keep in mind,I have to make sure its working first and it has been mentioned that it may be able to be converted inside....I await:)

[istari_knight]

Ta for the links Al, and many thanks for the help yesterday,
Ill keep in mind,I have to make sure its working first and it has been mentioned that it may be able to be converted inside....I await:)

Thanks for uploading the pictures... This is the voltage change procedure:

http://i26.photobucket.com/albums/c129/istari_knight9/PM80vc_zps7c9b98db.png

Which is basically moving the cables from E to D.

Should make it clearer:

http://i26.photobucket.com/albums/c129/istari_knight9/pm801_zps4648bb33.jpg

Only problem is that its the Jap model which is the only model not specifically mentioned in the SM, it has UK,EU,US,AU etc etc but no JP. Is there anything printed on the other side of the board that might give us a clue of what the transformers primary's are ? If not I wouldn't like to risk it & recommend just using a stepdown... No point guessing when it comes to mains :)

[seoirse2002]

http://theartofsound.net/forum/attachment.php?attachmentid=10504&d=1378132256

http://theartofsound.net/forum/attachment.php?attachmentid=10505&d=1378132269


This any help?

[istari_knight]

Hmm I've been looking & thinking [always dangerous :lol:] If the service manual is to be believed moving the cables from E to D will make it 220v input... Cant guarantee it though & I don't think any more pictures are going to help i'm afraid.

Either way you'll still need a stepdown which makes changing it an exercise in pointlessness [unless you planning on moving to Europe!]

[seoirse2002]

Hi James,
Thanks for your input so far....as I haven't a clue about moving cables etc. a stepdown transformer looks like a better option for me at least,unless I can find someone on here to do it and check it all out for me.....I don't expect it for nothing obviously,but I suppose someone possessing the skills and test equipment could easily do it......know anyone?....ideally not too far from London?

[istari_knight]

Sorry I don't know of any tech's in the London area but Walpurgis [Geoff] might, I think he's local.

[seoirse2002]

Great,thanks,Ill pop him a message:)

[Audio Al]

George
If you get the correct fuse's and want to drive over to my house you are welcome to try again here with my 100v transformer

[Audio Al]

George is this now sorted ?

[seoirse2002]

Hi Al,
Sorry Ive been busy with other stuff....and thanks for your help so far...
I managed to order and get the fuses I needed and as I was out that way called in to Rob(Puffin). connected it up to his 100V transformer and got Sound!! but only from one channel and only with the source direct switched on....so that's something at least.Ive been meaning to post an update....Now all I need is someone to go through it and check it all and perhaps fix it for me as Rob has lent me the transformer....any takers?

I really need someone that knows the PM-80 as I have another one as well,(but a MK2)also not working...

[Audio Al]

PM sent

[Arkless Electronics]

According to those schematics it should be easy to set it to 240V.