, Various, custom made pair with problem

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Eric Michelson2004-02-23 22:21

I have a custom pair of acoustats. they are actually 2 pairs that have been combined to equal 2 large acoustats with ribbon tweeters onthe side. It appears that my low end transformers have a problem on one of the speakers. How can I test to see which transformer is bad, and where can I find a replacement? I don\'t know what to do and I love these speakers. Eric Michelson


Andy Szabo2004-02-23 22:21

The usual procedure is to swap the interfaces from one speaker to the other, in an effort to isolate the problem to the interface. If the problem follows the interface, then the problem is in the interface. This is usually the case, since the panels rarely, if ever, go bad.

Replacement transformers are not generally available, although a repair service is available at Sounds Like New (see information posted under “Refurbishing”). They do not sell parts, but they are capable of repairing your interface, and they claim to have a good stock of transformers available. Your best bet is to verify that the problem is in the interface, and then send it to them for repair. They can figure out the exact nature of your problem.

The transformers themselves are difficult to test, other than a simple ohmmeter test comparing each winding to a known good unit. However, even a malfunctioning transformer can pass an ohmmeter test. Typical transformer problems occur only under high-voltage conditions, when the voltage is sufficient for the winding(s) to arc over.

Besides the LF transformer itself, you may want to check the two 50,000-ohm, 50-watt resistors for the correct ohm-value and/or signs of arcing or burning. These resistors are fairly reliable, but I have seen them go bad. They are readily available from electronics distributors. (This last paragraph assumes you have the MK-121 series interfaces.)

Gary Clausen2007-06-04 17:46

I have seen the insulation on one of my bass transformers appear thin in one spot. Perhaps broken internal conductor as I had week/distorted bass from one of my interfaces. splicing and resoldering fixed it the put some teflon shrink tubing over the splice. BTW, does anybody know the insulation used for the Medallion leads. Does seem like teflon to me, but not sure?

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