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U.S Tube Fisher Purchase?


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I was very keen to purchase a 30 watt 1962 Fisher tube amp at auction. 

But on inspection it has an American plug, so must be 110 volt.

So Step Down Transformer as well as a cheap variac ($189) must be factored into the price. 

I can't do more than look at it.

The seller knows nothing, its an auction.

I've read previous posts and have decided to take the chance of a step down receiver degrading the sound quality, if the price is right.

I suppose the previous owner ran it on a step down?

Can it be powered up on a Variac and a step down transformer at the same time?

Thanks.

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Edited by The man who fell to earth
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More information is required. Pictures of the rear  panel would show the mains  power specifications and it may be a case of the amplifier being  actually a dual voltage type.  If this is so, then to comply with Australian standards the mains lead would need to changed to a three wire type, something that was not always carried out in the 1960,s with imported American equipment.

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1 hour ago, The man who fell to earth said:

I was very keen to purchase a 30 watt 1962 Fisher tube amp at auction. 

But on inspection it has an American plug, so must be 110 volt.

 

Most probably.  However, a friend of mine has a CDP (with a 2-wire mains cord) which has a 2-pin Yankee plug - yet he's got it plugged into a 240v wall socket (via a plug-converter).  :)

 

Quote

So Step Down Transformer as well as a cheap variac ($189) must be factored into the price. 

 

Why do you need a variac as well as a 240v-110v step-down-tranny?  This should work excellently (given it's a power amp ??

  • Jaycar MF1084

 

I use this with my 110v us LP cleaning tank/blow dryer.

 

Andy

 

 

Edited by andyr
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1 minute ago, andyr said:

 

Most probably.  However, a friend of mine has a CDP (with a 2-wire mains cord) which has a 2-pin Yankee plug - yet he's got it plugged into a 240v wall socket (via a plug-converter).  :)

 

 

Why do you need a variac as well as a 240v-110v-step-down-tranny?

 

Andy

 

 

Thanks, 

His CDP would be dual voltage.

This 1960s tube amp wouldn't be (I'm 90% sure).

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10 minutes ago, The man who fell to earth said:

Thanks, 

His CDP would be dual voltage.

This 1960s tube amp wouldn't be (I'm 90% sure).

 

So why do you need a variac as well as a step-down tranny?

 

Andy

 

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4 minutes ago, The man who fell to earth said:

It's a 1962 'TUBE' amp that was last plugged in 'who knows when'.

It is necessary to bring the device up to full power very slowly to avoid shocking it's components and to observe any problems that require immediate shutdown.

 

Aah, OK - yes, I would probably want to do the same.  :thumb:

 

Be aware that, as a nearly 60-year old amp ... you should replace every electrolytic cap!  ?

 

And re. your recent pic ... it seems to be a mono amp?

(Each input has just 1x RCA socket and there's text which says "Left Speaker"?

 

Andy

 

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9 minutes ago, Andrews_melb said:

@andyr it does have two output trannies so should be some kind of stereo set up i would guess?

 

edit: looks like the right channel is on the top of the amp

 

Aah, OK - missed that!  ?

 

Andy

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@The man who fell to earth The original question wont get lost mate, all good.

Try to get this moved to the diy section.

 

Your spot on about wanting to bring it up slowly

As Andy mentioned the caps will probably be cooked. Have you built valve amps before so you know how to refurb this? Looks like itll be a great project. 

Will it be covered up or fully exposed on a rack? Id be worried about getting shocked 

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Nope, I'm a fool.

I will stay away from touching it (I love making and listening to music, I'm no scientist, electrical engineer)

I have done my research and the resto on this will be costly and time consuming.

Providing I can find someone to do the resto.

But first I need to know if I should buy it at all.

If it can't be powered up on both a Variac and Step Down Transformer simultaneously then it's just a parts amp.

Edited by The man who fell to earth
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19 minutes ago, The man who fell to earth said:

But first I need to know if I should buy it at all.

If it can't be powered up on both a Variac and Step Down Transformer simultaneously then it's just a parts amp.

 

The variac brings the Oz mains voltage up from 0v to 240v.  So that plugs into the wall socket.

 

The 240-to-110v step-down transformer plugs into the variac and simply converts what it's fed - 'Xv' - into 'X x 110/240v'.

 

So, yes, for testing purposes, you use both variac and step-down.  Once you've sorted out that the amp is running OK (and replaced the electrolytic caps in the PS) ... you no longer need the variac.

 

Andy

 

Edited by andyr
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9 minutes ago, Karl Rand said:

https://www.ozvalveamps.org/valvetechs.html

Before jumping in you may want to phone one of these bods. 

Thank you. 

I wont be jumping in. 

This will be a slow, careful process, carried out by professionals.

I spent time saving for the amp. Now i will need to save for the resto. So it wont be quick. Thanks

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Guest Muon N'

You can just use the variac, just don't take it beyond the rated mains voltage for the amp, 110 or whatever.

 

Edit: I would have a tech' look over it first.

Edited by Muon N'
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The procedure I would suggest, keeping in mind the age of the amplifier and  needing to replace suspect  component parts, is not to follow the path  of  the Variac and step down transformer additions. The  amplifier uses a mains  transformer that is rated 50 to 60 Hz and this can be rewound to suit the Australian  standards. This is the neatest method of conversion and should cost about the same to implement as that of a stepdown transformer. If your Fisher model is the X100 and the  output valves are the original 7189 A  types, the Russian 6Pi14Pi  can be used as a replacement although some small changes to the valve socket wiring may be needed.

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1 hour ago, VanArn said:

The procedure I would suggest, keeping in mind the age of the amplifier and  needing to replace suspect  component parts, is not to follow the path  of  the Variac and step down transformer additions. Tcertainly the best approachhe  amplifier uses a mains  transformer that is rated 50 to 60 Hz and this can be rewound to suit the Australian  standards. This is the neatest method of conversion and should cost about the same to implement as that of a stepdown transformer. If your Fisher model is the X100 and the  output valves are the original 7189 A  types, the Russian 6Pi14Pi  can be used as a replacement although some small changes to the valve socket wiring may be needed.

 

^^^ what he said, @The man who fell to earth:thumb:  (Although I would suggest a 50Hz replacement transformer (rather than getting the existing one re-wound); I understand 50Hz transformers have more iron in their core than 60Hz transformers.)

 

Andy

 

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4 hours ago, DEANO23 said:

Fisher was imported here and there were 240volts models but with a US plug ? Makes you wonder, that's a stereo model the left on the back the right channel is on the top side ironically on the the right. 

OMG !!!

I bought her.

More than I wanted to pay, but that's auctions, if the auctioneer had run it differently I would have saved $118. But she's home. I will let her sit untouched for a few days before a photo shoot.

U.S.A tubes (don't say fisher). That's as far as I have gotten. I just walked in the door.

 

I'm still a touch confused (and hopeful).

How do I tell the difference between an Aussie import 240v with u.s plug, and a 110v u.s version?

 

Oh and she is an X200 (updated KX200).

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5 hours ago, andyr said:

 

^^^ what he said, @The man who fell to earth:thumb:  (Although I would suggest a 50Hz replacement transformer (rather than getting the existing one re-wound); I understand 50Hz transformers have more iron in their core than 60Hz transformers.)

 

Andy

 

The Fisher  mains transformer suits  50 or 60Hz mains frequency. What has to be considered is the height of the unit as there is a little available   clearance  when the case is fitted and a suitable   off the shelf replacement would be a problem to find. Otherwise   you  may have to go for  a custom built transformer  and then you may  just as well rewind the old one. Modern insulation and wire coatings are superior to materials used in the 1960s. The  original output valves are more likely to be 7868 types which were unavailable for many years and these used  a special Novar  socket.

Other replacement types such as the 6L6WGC ( Russian 6Pi3C-E ) are readily available  providing an Octal valve socket is fitted.

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1 hour ago, VanArn said:

The Fisher  mains transformer suits  50 or 60Hz mains frequency. What has to be considered is the height of the unit as there is a little available clearance when the case is fitted and a suitable off the shelf replacement would be a problem to find. Otherwise you may have to go for  a custom built transformer and then you may  just as well rewind the old one. Modern insulation and wire coatings are superior to materials used in the 1960s.

 

Understand, now.  Thanks, VA.  :thumb:

 

Andy

 

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7 hours ago, DEANO23 said:

Fisher was imported here and there were 240volts models but with a US plug ? Makes you wonder, that's a stereo model the left on the back the right channel is on the top side ironically on the the right. 

Took the case off.

Found the mains specifications.

Bummer.

I think I'd rather use a step down and keep her original to the u.s market, sound quality sacrifice maybe. 

7591 tubes. 

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P8131188.JPG

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