Transformer replacement for AU217

[dbeugeling]

Recently, I bought a non-working AU217.
The fault was a blown internal fuse in the transformer.
I managed to get it out and made a bypass. Now the amp is working.
Still, I‘m a bit worried, because I had to ply and cut some isolating paper etc.
Is there somebody who van advise me on buiing a replacement transformer?
I could not found any. Maybe two toroid transformes will do 24-0-24 Nd one for 0-20 V)

thanks.

 

[Hyperion]

You'll probably be OK with it how it is, as I understand it the fuse that was blown is a 'thermal fuse' designed to protect the transformer from overheating dangerously. The unit probably had a fault which caused the overheating and thus the blown fuse. Of course I haven't seen what you have done, but providing you were careful, and used good quality electrical insulating tape or sleeving to cover any bare wire you should be OK. And also what happened in this case is quite common, there are many units in use where the thermal fuse has been bypassed in the way you describe.

Having lost the protection of the thermal fuse, make sure any conventional fuses in the unit are the correct rating and type, this will ensure electrical safety is maintained.

My advice:-
Don't change the transformer for anything other than an original from another AU-217.

 

[dbeugeling]

Thank you!
It seems that there are different versions of the amp.
One has internal voltageselect on a board and has mains outputs and an other has a voltageselector on the back, an no mains outputs.
Which is the newer one ?
Dick

 

[Sansuiman]

That is more a matter of units made for different markets. Units made for sale in tbe US and Canada had to be manufactured for 120 volt operation only. These units have a power transformer that only has a single primary and therefore no voltage selector. Units that were made for general export sale were equipped with a multi voltage selector and therefore had a power transformer with multiple primaries.

If you find a power transformer from a general export unit of the same model, you can use that, but will need to wire up the 120 volt primary directly, and properly insulate the wiring for the other primaries. Keep in mind that the AU-217 had a revised version, the AU-217 II, which is different enough that the power transformer from that model probably cannot be used.