Re: Damping Factor, output resistance....

Posted by Tom Dawson (A) on November 12, 2001 at 19:29:02

In Reply to: Damping Factor, output resistance.... posted by Thorsten on November 12, 2001 at 16:17:14:

"As to damping factors significantly above 1 - they don't exist in reality."

Not to get involved in a gee-whiz war of semantics by 'neglecting' VC resistance in the denominator of such an equation, but the conventional definition of speaker/amplifier damping factor which might be stated as being the values of load impedance divided by the source impedance at, for instance, the speaker terminals, or, if one prefers, the amplifier terminals is more serviceable than the alternative you propose.

For instance, it is of use in explaining how back EMF from,say the woofer driver can appear as audible output at the midrange or tweeter in a single amped multiway speaker.

And, yes, FWIW, my OTL amplifier is perfectly capable of negative damping factors and the potential instabilities into ungodly loads such can bring, given the positive current fb loop that is included in its design.

Btw, my OTL maintains its response flatness to well beyond 100khz within 3db below its slew limit into 8 ohms. Not bad for a purely thermionic amplifier, wouldn't you say? I picked its 3db low end cutoff to be 1hz, trending down to unity gain at DC. No servos, no regulators at all and the only solid state devices are rectifiers driving the CLC filters for all supplies.

Added on Date: 19:26:33 11/12/01

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Follow Ups Full Thread

Topic - Emulating tube amp source Z w. solid-state - is series RL network enuff? - freddyi 12:27:11 11/12/01 (17)

Damping Factor, output resistance.... - Thorsten 16:17:14 11/12/01 (10)

Re: Damping Factor, output resistance.... - PÃ¤r 04:03:26 11/13/01 (3)

-ve impedance - Pete McK 17:18:45 11/13/01 (0)

Re: Damping Factor, output resistance.... - Tom Dawson 09:19:50 11/13/01 (1)

Tnx both :-) - PÃ¤r 00:10:51 11/14/01 (0)

Are you saying NS1000 drops well below 4 ohms, Thorsten? - geeber 19:37:45 11/12/01 (0)

Re: Damping Factor, output resistance.... - Tom Dawson 11/12/0119:29:02 11/12/01 (0)

Re: Damping Factor, output resistance.... - Tom Dawson 18:52:00 11/12/01 (2)

Nominal Load and Reality - Thorsten 03:35:12 11/13/01 (1)

Re: Nominal Load and Reality - Tom Dawson 08:41:03 11/13/01 (0)

Re: Damping Factor, output resistance.... - freddyi 16:57:14 11/12/01 (0)

Re: Emulating tube amp source Z w. solid-state - is series RL network enuff? - Tom Dawson 12:31:15 11/12/01 (5)

Re: Emulating tube amp source Z w. solid-state - is series RL network enuff? - freddyi 12:40:46 11/12/01 (4)

Re: Emulating tube amp source Z w. solid-state - is series RL network enuff? - Tom Dawson 13:32:05 11/12/01 (3)

Re: Emulating tube amp source Z w. solid-state - is series RL network enuff? - freddyi 14:41:27 11/12/01 (1)

Re: Emulating tube amp source Z w. solid-state - is series RL network enuff? - Tom Dawson 15:29:48 11/12/01 (0)

Re: Emulating tube amp source Z w. solid-state - is series RL network enuff? - Tom Dawson 13:40:55 11/12/01 (0)

Follow Ups

Re: Damping Factor, output resistance.... - Tom Dawson 11/12/0119:29:02 11/12/01 (0)

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