From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paco Date: Wed, 23 Jun 1999 18:35:10 +0000 Subject: Re: Reducing "noise" from output Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org On Wed, 23 Jun 1999, Bryan Scaringe wrote: > So: What is the difference between line-out and speaker-out, > specificly from a functional standpoint. Is line-out expected to > be sent to an amplifier that will control bass/treble/vol? Exactly. For line-out, you have minimal control over the amplitude of the signal. "Line-level" voltage is (I believe) 2.2V, peak-to-peak. Volume control of line-out allows you to change this peak-to-peak value, but not significantly. Line-out signals are meant to go to another device which will control the bass/treble/volume. (ie, your stereo) Speaker-out signals are amplified *on-the-card* and provide enough juice to power speakers themselves. This on-card amplification may be the cause of your hiss. (I'm not too sure if the on-card amplifiers are very high-quality on an AWE64.) > Is this why line-out is less responsive to bass/treble changes > using "aumix" than speaker-out? BINGO! Bass and treble controls function just like the volume control for line-out; they *do* cause changes in the signal, but not significant ones. You can think of bass and treble controls as "turning up the volume" of the low or high EQ bands. regards, Chad "Paco" Walker