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Path: utzoo!decvax!decwrl!sun!idi!oliveb!allegra!prem
From: prem@allegra.UUCP (Swami Devanbu)
Newsgroups: net.audio
Subject: Sorry about previous posting, This one's right (I hope)
Message-ID: <5415@allegra.UUCP>
Date: Tue, 19-Nov-85 08:31:21 EST
Article-I.D.: allegra.5415
Posted: Tue Nov 19 08:31:21 1985
Date-Received: Thu, 21-Nov-85 03:20:44 EST
Distribution: na
Organization: AT&T Bell Laboratories, Murray Hill
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Replace this line with your message
Subject: Power amplifier questions
Newsgroups: net.audio
Distribution: na




[  Burp! ]

I have some questions about power amplifiers:


a) Is there any data (or theoreritical reason) that would
   cause one to suspect that amplifiers with "intelligent"
   power supplies (NAD, Carver, Proton)  would have greater
   tendency for Transient distortions ?


b) Does bridging cause any additional problems in terms
   of phases being different between the two sides of an
   amplifier, and the different drain on the power supply ?


c) Does high current capability on the output side have
   anything to do with anything ? 


d) Is this calculation correct: The slew rate for the
   NAD 2200 is rated at 35 V/MicroScond, or 35 megavolts/sec.

   for a frequency of 20 KHz:

   Signal: sin2PiFt,  F = 20,000.
   Derivative: 2PiFcos2PiFt, at t=0 (crossover point),
   derivative =~ 125K times the signal amplitute volts/sec.

   So max signal amplitude, approx: 280 Volts.

   To deliver rated 400 W transient power into 8 ohms, needed
   voltage is approx 58 V.

   So why should I give a flying findangle to get an amp with
   a higher slew rate ? Assuming, of course, I was using a
   CD, which has lower bandwidth than an LP :->.



If there is enough interest, I will repost all the answers.



{ucbvax,vax135,ihnp4}!allegra!prem