In Reply to: RE: Dear Alan posted by ahendler on December 25, 2015 at 13:32:02:
Futterman amplifiers are capacitor-coupled. The Berning ZOtl amplifiers are not; they work by raising the audio signal so it "rides" on a frequency around 250 KHz, then the carrier frequency is filtered out at the output by use of a small inductor, rather than an output transformer. Because the carrier frequency is so high, only a small inductor is required which makes it possible to achieve very wide bandwidth and low distortion. I'm sure this is a gross over-simplification, but for sure David Berning is a brilliant guy. Pretty much nothing he designs is ordinary. Absent that small inductor, the Berning ZOtl amps are direct-coupled.EDIT. I'm sure there's an electronic network involved too, in filtering out the carrier frequency, not just an inductor.
Edits: 12/25/15
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Follow Ups
- Actually,... - Lew 15:40:16 12/25/15 (14)
- RE: Actually,... - ahendler 20:18:34 12/25/15 (13)
- RE: Actually,... - cpotl 22:54:32 12/27/15 (1)
- Thanks. - Lew 05:42:21 12/28/15 (0)
- single ended OTL? - Cousin Billy 02:02:20 12/26/15 (10)
- RE: single ended OTL? - Banat 06:55:39 12/26/15 (9)
- Banat, thank you - Cousin Billy 07:14:39 12/26/15 (8)
- RE: Banat, thank you - ahendler 20:15:08 12/26/15 (7)
- In addition,... - Lew 08:11:02 12/27/15 (1)
- It does. nt - Ralph 09:04:25 12/28/15 (0)
- I Love and thank everyone - Cousin Billy 00:23:54 12/27/15 (4)
- You can make higher power SETs,... - Lew 08:18:33 12/27/15 (3)
- RE: You can make higher power SETs,... - Banat 10:44:30 12/27/15 (0)
- RE: You can make higher power SETs,... - Cousin Billy 09:49:38 12/27/15 (1)
- RE: You can make higher power SETs,... - Lew 12:33:48 12/27/15 (0)