From: boris (boris@usf.org)
Date: 04/03/00-10:20:20 PM Z
Here, I'm forwarding the message I posted to the iopener list a while
before.
---------- Forwarded message ----------
Date: Wed, 22 Mar 2000 21:38:02 +0000 (GMT)
From: boris <boris@usf.org>
To: iopener@scsiboy.com
Subject: Line level audio outputs
I was just reading the datasheet for the National Semiconductor LM4835,
which is the audio amplifier used in the IO. Quoting from the datasheet:
[Emphasis mine]
DOCKING STATION
In an application such as a notebook computer, docking station or *line
level* outputs may be required. Pin 9 and Pin 13 [right and left,
respectively] can drive loads greater than 1kOhm rail to rail. These pins
are tied to the output of the input op-amp to drive powered speakers and
other high-impendance loads. Output coupling capacitors need to be
placed in series with the load.
[snip]
Although the single ended outputs of the output amplifiers can be used to
drive line level outputs, it is recommended to use Pins 9 and 13 to
achieve better performance.
That outright says it almost clear as day, doesn't it? Might be easier
than Ryan is making it out to be... Apparently all that's needed is two
capacitors between .33 and 1 uF. Also, there is mention that the volume
control does NOT affect these outputs. Looks like just the thing for us.
boris
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