DCAudioDIY.com

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Walt

The 16309 is highly prone to failure. Though generally considered the better-sounding of the two, it's less desirable because of the tendency toward open primaries. According to Mike LeFevre of Magnequest, the 16458 replaced the 16309 due to reliability problems. It's possible that Kittleson had it backwards but I don't know for sure. W5's with the larger 16458 are considered a safer buy these days.

There's a lot of back and forth about why the 16309's were so prone to failure. I've seen examples with corrosion on the windings from faulty potting. I myself have one with an open screen winding. Some blame the underrated coupling caps in the original W5, which would leak or fail and cause red-plated, taking out one primary or another. Heathkit eventually recommended the installation of a surgistor to reduce the turn-on surge, which could go well above 600VDC.

A year or two ago I reworked an 807 amp and I used two different output transformers. The P-P impedance was the same, but the interleaving was different. These were experimental transformers I had made during the development of my EA2101 amp. Both Jim G. and Charlie P., both critical listeners, felt it was a very successful build.

By the way, I might mention that I have some output transformers that I am not using that I would sell. I have one pc. Partridge type CFB/0/0.95. This is 10k primary p-p with eight secondaries each 0.95 ohms. I also have a pair of Dynaco 454216.

Oh shoot, I could have used that Patridge six months ago when I was looking for a mate for mine. I finally gave up and sold it, but I'm happy with my Peerless's.