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Re: Class A, AB1, B, C Operation/Modes [message #96353 is a reply to message #96344]

Thu, 09 February 2023 21:01

gofar99
Messages: 1949
Registered: May 2010
Location: Southern Arizona

Illuminati (5th Degree)

Hi, MLs act like huge capacitors. They go from just over 4 ohms at low frequencies to 1 ohm at 20K. The slope of impedance can give many amps fits. It was why I added 3 db of frequency limited NFB to my amps. I figured they were about as tough a load as anything anyone would use. (some crossovers might be worse though) I have not had any misbehave without it...but testing shows a strong resonance point in most of the amps at about 70-85KHZ. So I start the slope at about 25-30K and it insures stability no matter what the amp sees on the output side. I have tested all of the various sizes with and without the NFB and have not been able to get any to mess up...still a couple of parts is cheap insurance. In the commercial versions and shown on the diy schematics I show NFB defeat switches and most folks can only say that the use of NFB cuts the gain by a few db. No surprise there...but in a blind test can't tell which one is which.

Good Listening
Bruce

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[Message index]

		Class A, AB1, B, C Operation/Modes By: positron on Sun, 05 February 2023 20:40
		Re: Class A, AB1, B, C Operation/Modes By: Wayne Parham on Sun, 05 February 2023 20:54
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Mon, 06 February 2023 20:38
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 07 February 2023 16:13
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Tue, 07 February 2023 19:33
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 07 February 2023 20:37
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Thu, 09 February 2023 21:01
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 09 February 2023 21:35
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 28 February 2023 19:04
		Re: Class A, AB1, B, C Operation/Modes By: Wayne Parham on Wed, 01 March 2023 08:28
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Wed, 01 March 2023 19:45
		Re: Class A, AB1, B, C Operation/Modes By: positron on Sun, 05 March 2023 00:33
		Re: Class A, AB1, B, C Operation/Modes By: Wayne Parham on Sun, 05 March 2023 08:05
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Sun, 05 March 2023 08:10
		Re: Class A, AB1, B, C Operation/Modes By: positron on Mon, 06 March 2023 19:01
		Re: Class A, AB1, B, C Operation/Modes By: positron on Sat, 06 May 2023 22:32
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Tue, 09 May 2023 21:30
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 11 May 2023 00:26
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 05 September 2023 23:48
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Fri, 08 September 2023 21:12
		Re: Class A, AB1, B, C Operation/Modes By: BreakneckRedneck on Sun, 24 September 2023 00:42
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 12 October 2023 11:21
		Re: Class A, AB1, B, C Operation/Modes By: positron on Fri, 03 November 2023 12:22
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Fri, 03 November 2023 20:58
		Re: Class A, AB1, B, C Operation/Modes By: positron on Sun, 05 November 2023 01:38
		Re: Class A, AB1, B, C Operation/Modes By: positron on Thu, 07 December 2023 23:12
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Mon, 18 December 2023 20:20
		Re: Class A, AB1, B, C Operation/Modes By: positron on Tue, 16 January 2024 21:32
		Re: Class A, AB1, B, C Operation/Modes By: gofar99 on Wed, 24 January 2024 20:31
		Re: Class A, AB1, B, C Operation/Modes By: positron on Mon, 08 July 2024 20:22

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