Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!watdcsu!bmaraldo From: bmaraldo@watdcsu.UUCP Newsgroups: sci.electronics Subject: Re: Choosing Cap Size in Power Supply Message-ID: <3691@watdcsu.waterloo.edu> Date: Tue, 28-Jul-87 21:55:05 EDT Article-I.D.: watdcsu.3691 Posted: Tue Jul 28 21:55:05 1987 Date-Received: Wed, 29-Jul-87 06:22:40 EDT References: <5705@ut-ngp.UUCP> <1884@kitty.UUCP> <935@sdcc7.ucsd.EDU> Reply-To: bmaraldo@watdcsu.waterloo.edu (Commander Brett Maraldo) Organization: Unit 36 Research Lines: 30 The usual modification to an audio amplifier power supply is replacing the old caps with higher quality caps of the same capacitance or higher. Also, the addition of a .47uF and 5uF polyproylene bypass cap helps to clean up the sound. I have added as much as .25F to a power amplifier and notices an incredible improvement in the low end transient responce. These modifications are of course audiophile related and my not make any sence in the real world. As you know, the world of the audiophile operates under a different physics :-) I generally put as much capacitance on the dc rails as possible. Under some operating circumstances, this may not be advised, but these unusual circumstances are unknown to me. Also remeber to put a drainage resistor across the caps that'll drain them when the power shuts down. On large supplies it is best to have a relay close which that places the resistor in the circuit. I have welded a 3/8 inch drill bit to a quarter with my 40V .25F power supply. Brett L Maraldo -- -------- Unit 36 Research --------- "Alien Technology Today" ------------------------------------------- bmaraldo@watdcsu