Path: utzoo!attcan!uunet!samsung!brutus.cs.uiuc.edu!apple!fox!portal!cup.portal.com!ISW
From: ISW@cup.portal.com (Isaac S Wingfield)
Newsgroups: sci.electronics
Subject: Re: Help to eliminate pre-amp power-up click
Message-ID: <24126@cup.portal.com>
Date: 17 Nov 89 00:51:31 GMT
References: <184@vlsi.waterloo.edu>
Distribution: na
Organization: The Portal System (TM)
Lines: 17

If your preamp "pop" problem is like mine, it also occurs at
power off; after lots of head scratching, my preamp controller

1) turns on the preamp
2) delays 5 seconds, and turns on the power amp
3) at turnoff, turns off the power amp
4) delays 30 seconds, and turns off the preamp

BTW, the controller and preamp power supply are in a separate box
located about 4' from the low level electronics. The power switch
is on the preamp; when it's off, all power is off (including the
controller). When it's on, there is *no* 60 Hz or other power line
component in the wires to the power switch. Took a little work, but
hum is not a problem.

Isaac
isw@cup.portal.com