Re: Echo II Soundcard

["Scott Alfter" <KsIaLlLfStPeArM@MiEbRmS.NnOeWt>]

Romeo wrote in message <6q2h6l$btp$2@news1.anet.com>...
>Hi. I recently bought a IIgs that has an Echo II card in it. It seems to be
>some sort of mono soundcard. Is this thing worth having in a IIgs? I
thought
>the IIgs had awesome sound without need of an external soundcard? I plugged
>headphones into the "Echo speaker out", and got a lot of "hum". Are these
>things supposed be that noisy?

For the time, the GS's sound was the best you could get (who else had
hardware-based wavetable synthesis in 1986?).  Even today, it's not bad
(certainly better from a musical standpoint than a Sound Blaster 16, but a
modern wavetable sound card (such as an Ensoniq AudioPCI, which BTW is from
the same company that was responsible for the GS's synth chip) will sound
cleaner with its higher sample rates and higher resolution (16-bit vs.
8-bit).

"Sound cards" for the GS are little more than demultiplexers.  The Ensoniq
5503 supports up to 8 channels of audio output, but they're all multiplexed
onto one output pin.  Apple decided not to include the necessary
demultiplexing circuitry on the motherboard, but made a connector available
that had all the necessary signals.  GS sound cards hook into this
connector.  (Some cards also have software-controllable mixers and/or power
amplifiers for driving unamplified speakers.)
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