In Reply to: Question for Banat posted by Lew on February 18, 2014 at 10:45:03:
Hi Lew !10R cathode power res. bypased with 1000uF Elko alltogether with separate DC coupled driver results on so called `combined ` power tube(s) bias , where minor negative bias voltage is achieved automatic on cathode R/C member(s) , but major power tubes(s) negative bias voltage come as usual from separate DC coupled drivers cathode(s).
This solution is basically one good Compromise , since on the one side result in improved stability operation of output power tubes , but on the other side result in slightly to insignificantly reduced sonic performance of the OTL Circlotron Amp .
This mean that order of magnitude of sonic performance decrease is 1000 times or even less than in case when we want to use any type of the best feromagnetic transimpedanse power device ( read OPT ) , by use of this `combined` bias method highest possible sonic resolution Amp performance is still obtained , which is typical sonic characteristic for any good designed OTL Amp .
BTW , my formula to chose optimum value of cathode W.W. res. is R=1/10 of B+ , for example , if B+ is 140VDC than Rk have to be 14R , but since 15R is common available res. value than this sligtly higher value is good too .
Edits: 02/19/14 02/19/14
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Follow Ups
- RE: Question for Banat - Banat 08:07:09 02/19/14 (7)
- Another question about the cathode bypass capacitor - Lew 06:53:11 02/20/14 (6)
- RE: Another question about the cathode bypass capacitor - Banat 14:13:09 02/20/14 (3)
- I think I understand - Lew 14:30:34 02/20/14 (2)
- Just FWIW - Ralph 09:41:39 02/21/14 (1)
- Yes, I agree, 2 Hz cut-off - Lew 10:44:31 02/21/14 (0)
- RE: Another question about the cathode bypass capacitor - tyu 07:34:02 02/20/14 (1)
- I had a new question for Banat - Lew 08:12:53 02/20/14 (0)