From owner-freebsd-questions Thu Nov 26 09:56:56 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA18769 for freebsd-questions-outgoing; Thu, 26 Nov 1998 09:56:56 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from wolf.com (ns1.wolf.com [207.137.58.20]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id JAA18758 for ; Thu, 26 Nov 1998 09:56:54 -0800 (PST) (envelope-from dan@wolf.com) Received: (qmail 13869 invoked by uid 100); 26 Nov 1998 18:05:48 -0000 Message-ID: <19981126100547.A13666@wolf.com> Date: Thu, 26 Nov 1998 10:05:47 -0800 From: Dan Mahoney To: kent@iastate.edu Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Sound card as a cheap DAC References: <199811260539.XAA22064@isua4.iastate.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.93i In-Reply-To: <199811260539.XAA22064@isua4.iastate.edu>; from Kent Vander Velden on Wed, Nov 25, 1998 at 11:39:25PM -0600 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Hi. Can a sound card such as the SoundBlaster 64 Gold be used as an > inexpensive DAC? My goal would be to vary a voltage source under > computer control. I have tried to send a string of values into > /dev/audio and watch the response on an o-scope. I only seem to see > changes when the values going into /dev/audio are changing. This > makes me question my understanding of a sound card. Anyone have > experience in this area? I haven't looked at the output circuitry of a sound card recently, but I would expect it to be capacitively coupled. If so, you *would* only see output when the output levels were changing (i.e. AC output). Dan Mahoney dan@wolf.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message