How to connect impedance matching audio amplifier to impedance matching transformer?
Sep 21, 2011 at 10:28 AM Thread Starter Post #1 of 2


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Sep 21, 2011
I was wondering if anybody out there would be kind enough to help me hook audio amplifier to impedance matching transformer? I am trying to hook up KEMO M034N to HAMMOND 119Y30 transformer. I am having trouble knowing what pin to hook up at the transformer.
Below is the specs:
Mar 26, 2012 at 8:27 AM Post #2 of 2
The transformer you've chosen is available with two line level inputs, 25V and 70V.  The output taps are for speakers with ratings of 3.2, 8, or 16 ohms. The higher the impedance, the higher the output voltage. The Kemo M034N has a decent amount of gain in my experience, so choosing a transformer with a 70V line input to 8 ohm output is a good place to start, such as the 117F2 2W transformer. The 8 ohm tap of the transformer should feed into a 10K potentiometer (what Kemo recommends).  The pot's wiper arm is connected to the amplifier's audio input.  You may need to add an 8 ohm, 5 watt power resistor across the output tap in order to get a uniformly flat frequency response.  Good luck with your project.
BTW, the Kemo M034N amplifier is quite good.  I'm using one to drive a flat screen TV center channel speaker I built.

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