Replacement Transformer

[ilmenator]

I have a Kurzweil K2000R that has a problematic transformer: the damn thing makes a lot of noise, as it is vibrating and the whole chassis is resonating. A little as if there were 2 10.000 RPM SCSI harddrives running inside...

So I am looking for a replacement. Basically, the secondary outputs are 2x 14V and 2x 6V, with a center tap on each. I find it hard to find a single transformer that fulfills these specs, but I wonder if I could use two separate ones? Big question: Would I have to connect the center taps of the two secondaries to make sure the zero Volt potential is the same for both power sections?

[Zossen]

Hi,

here is the Service manual http://www.synfo.nl/servicemanuals/Kurzweil/K2000_K2000R_SERVICE_MANUAL.pdf,

under 5.1.2.2 you see a shematic , so i think you can use two transformers with no need to connect the center taps,

the internal circuit does everything for you, but

here you can make a transformator for your K2000R with original Voltage and center taps.

http://www.multi-circuit-boards.eu/en/pricing/toroidal-transformers/enquiry.html

the also make them fully encapsulated.

you can search for such a company, there are a lot of them in the World.

Hope i could help you.

best regards

Zossen

Edited April 29, 2012 by Zossen

[Imp]

I'd try to isolate the source of vibration from the chassis first.

E. g. mount it with some rubber elements or foam in between.

You could also try to tighten the package of the transformer, to reduce inner movement.

If it doesn't help, maybe cast it in resin.

[ilmenator]

here is the Service manual http://www.synfo.nl/servicemanuals/Kurzweil/K2000_K2000R_SERVICE_MANUAL.pdf,

Great find, thanks - the schematics at the end of that PDF also show that center taps should not be connected!

I'd try to isolate the source of vibration from the chassis first.

E. g. mount it with some rubber elements or foam in between.

You could also try to tighten the package of the transformer, to reduce inner movement.

If it doesn't help, maybe cast it in resin.

In my experience, tightening the package mechanically from outside does not work, as it will always come loose again. I tried that. Rewinding the transformer could do the job, but without the proper equipment it is extremely difficult and even dangerous, because you easily hurt the insulation lacquer.

De-coupling the transformer from the chassis could reduce the noise somewhat, but will not eliminate it. I'll detach it from the chassis and see/hear how much noise is left.

Thanks for sharing your ideas!

[ilmenator]

Old thread, but I though I'd post the solution to the problem described above anyways.

 

My K2000R now sports a bar clamp / vise that sits tight around the transformer package. I was not convinced before trying this, but it actually did the trick - thanks Imp! There is enough space in the enclosure to close the lid, so for me this is now a permanent solution.