, Interfaces, Medallion C

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Steve Morris2004-02-23 22:21

I am having a problem with one of my Acoustat Medallion C Transformers. I had a channel go out in my amplifier. On replacing the amp, the transformer on the side with the amp problem now produces a very thin sound, lacking any bass. I have ruled out a panel problem, as the speaker sounds great when the other transformer is attached. Any help with a diagnosis of the problem or a lead on a replacement would be most appreciated! Thank you.


Andy Szabo2004-02-23 22:21

From your description of the problem, it seems that you have a problem in the low frequency portion of the interface. There are three possible components: the 1-ohm resistor in series with the low-frequency transformer, the low frequency transformer itself, or the 50K-ohm resistors on the output of the low frequency transformer. But before you begin checking components, make sure the low-frequency tap is properly connected. The resistors are easy enough to check with an ohmmeter. Temporarily disconnect the low-frequency tap to get an accurate measurement of the 1-ohm resistor. This 1-ohm resistor is a 25-watt wire wound, and the 50K-ohm resistors (2 per interface) are 50-watt wire wounds.

The low frequency transformer (the largest of the three transformers) is tough to check by measurement. Your best bet is to exchange the transformer with the known good one in the other interface. Unfortunately, the transformer is the most likely failure: your failed amplifier channel may have damaged it (or vice-versa). You\'ll probably have to search the used market for a replacement. Since you have the Medallion interfaces, make sure you get a Medallion replacement transformer (identified by a black paper wrapper (not brown)).

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