[ARC5] ARC-5 passive filter take II

[J Mcvey]

It was going to be difficult to wind a torroid  with sufficient inductance to work in the 8K line, so I opted for the low z 8 ohm speaker circuit.AS it turns out, a common mode line filter torroid ( I love to re-purpose stuff) wired in series aiding mode provides about 200-250 ohms reactance at 700 Hz.The core material isn't the best for frequency response, but I think it will suffice.There are some of these type torriods that are double wound back such that each winding only occupies half the core on each side. The others are wound in the traditional way . The traditional 300 degree winding is more efficient for this purpose.
The insertion loss was about  2.4 db . None the less,  it was still loud enough with very little drive with just the series LC.
The final design will be the series resonant LC with a parallel LC across the speaker. 

Who knows? If I like it enough, I may spring for better materials! Stranger things have happened.




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