Thanks again, it's cool that there are people around willing to share
their expertise. Really appreciated! :)
I should emphasize that this is purely sentimental. MOD is the format
used for trackers, or sequencers, back in the days of 16-bit home
computers which had very limited RAM and disk space. A MOD is basically
a collection of so-called patterns which contain the sequence of samples
(~instruments) to be played in up to four channels, the note values for
each entry, plus special commands like volume changes, vibrato, volume /
tone slide, arpeggio, play speed etc.
Patterns are arranged in a list so it is possible to play the same
pattern or sequence of patterns multiple times with just one additional
byte needed per pattern in the pattern list. So far it is similar to
MIDI.
Eventually the samples, which typically occupy most of the payload,
follow one after another in the same file, basically a list of 8-bit (!)
waveforms with size info and optional loop info to enable a sample to
repeat itself at a given point and restart at another given point to
play indefinitely. This is where MOD is fundamentally different from
MIDI which relies on samples being stored in the playback machinery, and
configured externally such that the right instruments are patched. A MOD
would bring its own instruments at all times, ensuring the experience is
the same no matter what.
All this is very economic. A MOD is not a linear audio stream but relies
on repetition and saves lots of space by enabling playback of samples at
arbitrary frequencies so the same sample can be played in three octaves.
Just a few kilobytes of input could give you hours of playback. Plus, it
supported creativity a big deal because one could "steal" samples from
existing modules to use in one's own, and learn pattern arrangements,
effect commands and their overall use from others easily. Associated
programs like SoundTracker, ProTracker, StarTrekker etc. made it easy to
work with modules. Their results were used in the entire demo scene and
most of the games back in the day.
Amiga computers introduced this technique as far as I remember, and
added some "artifacts" like the low-pass filter that was usually engaged
on power-up to suppress digital noise interference in the analog
outputs, but would also cause the sound to appear pretty muffled. It
could be switched off by a command in the MOD file, which is what
virtually any composer did in the first step, or even be toggled for
effects if needed. Another problem with basically any home computer was
that the stereo separation was nearly 100%, i.e. the tracker channels 1
and 4 would play strictly on the left channel, 2 and 3 exclusively on
the right. This is almost painful when using headphones. While some of
that separation was desirable, the arrangement kind of falls apart. To
bring it all closer together, I used to help myself with a resistor
placed between the positive terminals of both audio outputs. The sound
field got narrower this way of course but with the right resistor value
the results were pretty good.
The same would have to be done in software now because I don't want this
permanent resistor in my signal path. Transcoders like XMP handle filter
and stereo separation through command line parameters as you stated.

But I see that I underestimated the effort needed to make it work in LMS
as desired. Not a big deal, this is kind of a low-level enthusiast
matter, and as hard disk space is no longer a big concern these days, I
may convert at least the top 100 modules of my collection to whatever
replicates them best at a good compression rate.



PN me if your Boom / Classic / Transporter display has issues!

LMS 7.9.0 on Windows Server 2012
1x Squezeebox Classic SB2
7x Squeezebox Classic SB3 (one waiting for repair)
7x Squeezebox Boom (two waiting for repair)
1x Transporter
2x Controller (one waiting for repair)
3x Touch (two waiting for repair)
1x Radio
------------------------------------------------------------------------
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View this thread: http://forums.slimdevices.com/showthread.php?t=108331

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