If you just want a simple amp for outdoor speakers then just find a used receiver. I personally have a few laying around, but I'm sure many people do, or they could be gotten for about $50 or so and that gives you input choices also. Or use a T amp if you have efficient speakers.

On the original thread, it was interesting to note the poster got to try the PS Audio Humbucker unit, although it didn't completely fix the issue enough.