In Reply to: Re: Choke Filters, and the Buzz... posted by mrfixit on February 9, 2003 at 11:35:41:
Lewis -I didn't change the power supply - always 800vdc. I started out running the 211's quite lightly - around 40ma. The GE spec sheet for 211's shows a class A operating point of 750v/34ma. I'm now convinced that they sound better at 800vdc/60ma. They should still have a very long life.
I'll be glad to draw up a schematic, and will hopefully post better pic's and some documentation in the next few weeks. My most useful comment is that you really need careful wiring around the 6C45's with grid stopper carbon comp resistors, and ferrite beads. There's a real "harshness" you'll notice as the 6C45's oscillate. When I first powered up my "clip lead" version you could actually see the RF on my TV. If I were to do it again I'd etch up some PC boards with a ground plane for construction. The rest of the amp was a pretty easy construction job.
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Follow Ups
- Re: Choke Filters, and the Buzz... - Gary Kaufman 02/9/0312:02:40 02/9/03 (1)
- Re: Choke Filters, and the Buzz... - mrfixit 12:24:27 02/9/03 (0)