Path: utzoo!utgpu!watserv1!ria!helios.physics.utoronto.ca!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!uunet!iconsys!jensenq
From: jensenq@iconsys.icon.com (Quinn Jensen)
Newsgroups: comp.dsp
Subject: Re: Digital Output and VU meters
Message-ID: <1991Mar13.210806.17231@iconsys.icon.com>
Date: 13 Mar 91 21:08:06 GMT
References: <50146@apple.Apple.COM>
Organization: Sanyo/Icon International, Inc., Orem, Utah
Lines: 10

> What does 0VU really mean?  I assume it is power related but I'm not sure of
> all the nuances.....and I suspect that there is a temporal dimension to it.

If I recall correctly, 0 VU equals 1 milliwatt sinusoidal RMS
into 600 Ohms (probably 1 kc is the standard tone).  So if you have
a 600 Ohm output with a 600 Ohm load, 0 VU is somewhere around .77 V RMS,
which is about 1V peak or 2V peak-to-peak.  So if you know what code
on your DAC would produce that voltage, then you'd have a standard 0 VU.
But that may not be as important as just providing a dancing bar graph
with an arbitrary 0 VU.