Melody Z-II Sound Card Review

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                      Review: Melody Z-II Sound Card
  Ralph Debusmann                                     rade@coli.uni-sb.de
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We already know of the positive impact of hobbyists on the Amiga - most
notably the Aminet of course.  Also done by hobbyists is a new and quite
ingenious piece of hardware - the Melody sound board for one of your Zorro
II/III-slots.  The card was designed by four German students in their spare
time, the KATO-Development-Group.  I was happy to be able to borrow board
#23 (of 24 built boards from the first series) and have a quick look at it.

So what is the Melody and what is the motivation behind it?  First of all,
the melody tries to substitute the Paula custom chip, i.e.  Paula's main
purpose: sound output.  While the Amiga's sound output remained the same
(8bit, 14bit with "cheats") during the last 12 years (!) PeeCees already
have 16bit sound output for many years.  The Melody sound board gives your
Amiga 16bit sound output at 44.1 KHz.

The second motivation behind the Melody board is that the developers wanted
to have a gadget which allows to listen to MPEG-Audio files from within a
multitasking environment - not easily possible since processor-driven
MPEG-Audio decompression (mpega) takes lots of CPU time even on a 060.
Thus the perhaps most interesting thing the Melody offers is the Texas
Instruments DSP, which not only allows 16bit audio output but also has the
capability to decode ISO-MPEG (Layers 1+2) in realtime.  That simply means
that you can listen to Audio-MPEGs with your Amiga while the decoding
process only takes a few percent and your main processor is free for other
tasks.

Installing the Melody is a breeze.  I just plugged in the Zorro II-board
into one of my A4000's free slots and had all the above described niceties
built into my Amiga.  The Amiga's native sound output (Paula) can be put
into the Melody card and is put through to your stereo.  This makes it
possible to listen to Paula's and the Melody's output simulataneously.  On
the software side I got a program called MPEGPlay to play MPEG-Audio Layers
1+2 and 16bit audio files in AIFF, WAVE and AUD format through the melody -
nice GUI included.  A special version of the "toccata.library" emulates the
Toccata soundcard on the Melody.  This makes for AHI-compatibility of
course and gives you the chance to run many applications which already
offer Toccata compatibility.  Proper AHI-compatibility through an own
Melody audiomode will be available soon.

After installing, you can use the melody for various tasks.  You can
utilize it for playing MODs, XMs and S3Ms using AHI under HippoPlayer or
DeliTracker, and you can play 16bit audio files including MPEG Audio
(Layers 1+2).  As a composer Melody can give you real 16bit output in
applications such as Symphonie or SoundStudio.  I confess that I as a
non-musician mostly played MPEGs (MP2s) through the Melody.

I should also note two drawbacks I found out using the Melody.  The one is
that the samplerate and -resolution are fixed at 44.1 KHz/16bit.  (i.e.
CD-Audio-rate) This decision has been taking to keep the price low.  While
reading through the preceding paragraphs you might also have noticed that I
did not talk about MP3-(MPEG Layer 3) compatibility.  The actual DSP only
decodes Layers 1+2 and thus fails when you face it with a song in Layer 3
format.  Although Layer 2 still provides for good compression ratios (about
1:7 to 1:8) and near-CD quality, Layer 3 is *the* hype format (ratios 1:9
to 1:12) in the Internet.  A cure in form of a chip upgrade is also in
sight for this problem, but as Layer 3-chips seem to be too expensive at
the moment, this should be regarded as a future option.

Concluding I should note that I've never had a nicer gadget plugged into my
A4000 than the Melody sound board.  I am even thinking about buying one
(the price of the upcoming non-developer boards should be around $175) just
for the fun it offers.  You can have dozens of near-CD quality-songs (in
MPEG Layer 2) on your harddisk or self-burned CDs and access to them via a
simple mouseclick.  And playing them takes no almost no processor time.
Playing 16bit music modules or samples whilst having real 16bit output also
is a nice option, although several features are missing in the standard
configuration of the Melody - to make for a reasonable price.  I should
notice last but not least that the Melody has been built in a very modular
way which allows for many upgrades (e.g.  a m56k-DSP, sampling facilities
and even a serial port extension like Hypercom).

For much more detailed information:
http://members.aol.com/tgruner
and
http://home.pages.de/~kato

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