Commodore Free 12/Commodore_Free_Issue_12_2007_Commodore_Computer_Club.d64/t.soasc faq

Text File | 2007-01-01 | 12.3 KB | 395 lines

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SOASC= FAQ - Frequently Asked Qestions:

PART 1
 There are bound to be people asking
themselves why I did it THAT way? Or
just people beeing incredible critical,
just because they have a sound system
that are 20 years newer and can TODAY
bring forward that awful static
noise, and details you'd never heard
before in authentic Commodore 64 music
This FAQ below will logically answer
ALL those questions.

http://www.6581-8580.com/index.htm

A: No, its not. The keyword is emulate
It means to simulate or reproduce
something in another environment that
its original environment An artificial
environment. Is this real then? No.
Therefore, the music MUST be recorded
from the real environment to ensure
the authentic and genuine sound of the
C64. Recording from hardware cards or
software emulators of the newest kind
is NOT authentic. That's the easy way,
I do it the hard way..so there! But,
don't get me wrong. The work done for
the software emulation of the SID
chips are really a incredible task.
Respect! Another thing is that the SID
chips have incoming capacitor lines
which are made out of natural elements
and this means that the filters are
impossible to simulate on a computer
100%. And do rememeber that 2 similar
chips and C64's will NEVER have the
exact sound on both! The filters are
based on nautral ingredients (which
are of the analogic world) and
therefore there will naturally
be deviations from emulation, clones
vs the real thing! C64 is not living
in a digital filter sound world..and
thats why the sound is so incredible
and this also apply for a lot of old
synthesizer equipment from the 80's...
like the Roland TB-303. Pure analog
sound which is NOT comparable to
software clones of today. (But that's
another battle story..

Q: "Cool, real hardware is the way to
go, but what chip revisions & batch
are you recording on?

A: The chips used for recording is:
"MOS 6581R4 3387 14" (Yes, no AR
markings!) and the "C= CSG 8580R5 2689
25". Hopefully the whole 90000+ tunes
will be recorded on these if they do
not fail during the 3-4 month process!

Q: "Hey, my favourite tune sounds
wrong, I can't remember this version!

A: In most cases the tune are
authentic and is exactly how it
sounded when played on a real C64 with
6581 or 8580. Remember that composers
designed tunes to be perfect on the
6581, and when 8580 came out a few
years later the damage was of course
not possible to fix. They could not
have known that the filters was
changed on the 8580. This is the most
important part to remember. Tunes ARE
and WAS specifically  designed to that
of the composer had in his machine.
But how the hell can you know what the
composer intended? I many cases, you
don't - so please use the guidelines
below for help! Guidelines for
choosing the correct MP3 version to
download/listen to:

1: Make sure you download the MP3
file (either 6581 or 8580) as
suggested by HVSC and also indicated
in our database. If still not sounding
okey, proceed to step 2.

2: Download the SID file instead.
Tweak settings in SIDPLAY2w to force
6581 or 8580 model to use. If the same
problem (missing sounds or channels)
is there, then the SID file is
supposed to sound like that on the
opposite model or the SID is a bad rip
(difficult to determine)

3: There are known differences
between 6581 and 8580 recordings. For
instance the sample playback on 8580
may be low or missing. Please try the
6581 version instead. Even between
revisions of the same chip the sound
can be different, so remember that!

4: Please try and remember what kind
of C64 you heard the tune on
originally "back in the days" Download
the appropriate MP3 file, and that
should be it.

5: Also, to confuze you even more.
The MOS6581R4 used for recording has
some really strong filtering, so if
thatis not pleasing or you can't
remember, a safe say would be that the
MOS6581R2 version is the one you seek!

6: Download all MP3 versions (6581
and 8580) and choose the most suiting
one for your ears and stick to that!
General:The sound of C64 is analogic
and sounds differently on each chip
and given between the same revisions!
So a quick estimate from me:1982-1988
= Go for the 6581 versions(100%)
1988-1993 = preferred model unknown
1993-2007 = preferred model 8580 (but
still not 100% trustable)

BUT also remember that tunes made
1982-2007 WITH samples will not sound
correct on 8580 (in most cases) so
that too is a little bit confusing I'm
afraid. If the problem is still there
and you are certain that something HAS
gone wrong during the recording,
please post the bug and we shall
investigate and give feedback.

Why we didn't do this intially during
the pre-recording process is simple:
People was used to the music they
heard on whatever model they had
regardless of what the tune was
originally composed on "back in the
days". So, if a tune was suggested to
be played with a 6581 model (like tune
9 in Last Ninja) it would have a
special filtersaw string in the
background. But, on a 8580 the same
sound would not be present. So, for
people only listening to tune 9 in
LastNinja on a 8580 model, they would
not have recognized the "new"
filtersaw string in the background if
they downloaded the 6581 MP3 version
of today. So, it was a easy decision:
We HAD to record everything on both
models to suit everybodys childhood
memories: )

Q: "Hey, my favourite tune is missing
1 to 0.5 second (start or end), and
the looping is not perfect!"

A: The tune lengths were extracted
from HVSC own songlengths.txt file
which do not contain that much of
precision.Furthermore,it is well known
that a number of song lenghts are
really wrong. The songlengths.txt is a
beta project still.But in time, HVSC
will probably take care of this, and
even adjust the lengths to more
precise numbers. Its rounded to the
nearest second. I have added about 0.8
second to the recording in my SIDREC
software to compensate. This means
that your favourite tune or sound
effect will either be perfect, missing
0.2 second or having 1.3 second too
much making a seamless loop not
possible. The other thing you have to
remember is that the SOASC= recording
is an AUTOMATED process and there{SHIFT-*}s NO
WAY I could load each tune into Adobe
Audition and manage this for approx
95000 tunes. That is IMPOSSIBLE. BUT,
of course such things are irritating,
so requests for re-recordings and
manual mastering is an option through
our FORUMS!

Q: "Hey, my favourite tune is having
a click/pop audio problem somewhere!!!

A: Some of the SID tunes played on
a real C64 contains peaks beyond what
you could believe. Its a analogic
world on the C64 and things CAN get
out of hand. I have not used any
software to prevent clipping as this
can destroy certain elements of sounds
in other tunes probably. Furthermore,
the audio in recording volume is ONLY
about 25% of the REAL signal. This
should prevent clipping in 99.8% of
the songs. After the recording a
NORMALIZE function is performed on the
tune, maximizing it to the fullest
volume possible. If the peaks are
already recorded with 25% volume, the
peak will naturally still be there.The
click/pop problem is a minority of the
tunes. You should try the 6581 or 8580
version to determine if the problem is
on both of them and report back to the
FORUMS. Maybe even request a
re-recording where the clipping is
manually removed by us. And again,
remember the SOASC= project is an
automatically based project, no human
involment to fine tune each SID song.
Some sacrifices will be present, but
all things can be fixed. There is hope,
"keep hope alive" (C) TCM!

Q: "Hey, almost all tunes have an
annoying click in the beginning!  WTF?

A: Yes, this is the actual software
INIT being done by PSID64 for the SID
chip. Its just the same click you will
hear on a real Commodore 64 if you
were to start the actual game or demo
yourselves. I tried to fine adjust
the recording to avoid this, but there
are some minor milliseconds to which
to work on, so a lot of tunes were
chopped off about 0.1-0.5 seconds in
the beginning instead. So, I decided
to adjust it back to make sure the
tunes were not chopped off in the
beginning. Sorry for this, its just
the nature of the SID chip...and since
the SOASC= is authenthic I guess it
have to be in there...uhh. But maybe
it wont play on all MP3 players both
hardware and software, depends on how
for instance you have the fading
between songs (ie crossfading in
WinAmp) or that your ipod ignores the
first 0.1 seconds and skips it...you
never know :

Q: "Hey, Have you guys deleted some
recorded files, where are the "_PSID"
recordings?

A: The _PSID are files that were back
in the Amiga days hacked to be played
perfectly with samples when using
Amiga PlaySID. Today, the result
(when played on a real Commodore 64)
is sample playback missing or totally
screwed up etc by using PSID64 (which
the entire SOASC= was used for). I
think there are possibilities to
record even the PSID files by using
MMC64 or another dedicated SID player
on the C64 itself, but this has not
yet been researched upon. In time I
will investigate and prepare them for
new re-recording upon the next SOASC=
major recording process during 2007.
Today, the PSID files resulted in
incredible noisy files when processed
by the SOASC= recording technique for
instance. This is also mentioned in
HVSC FAQ, and they have intentions to
re-rip all _PSID tunes and make them
real C64 ripped files which will be
played correctly on a real C64. They
are not really suitable and can't be
trusted at all, so we filter them out!

Today, most tunes are duplicated with
both the PSID and the regular SID
format anyway, so this question will
be null and void during time.

Q: "What actions did you take to
ensure recording of PAL/NTSC based
tunes?

A: This is a bit of a troublesome
point. All tunes were played on both
6581 and 8580 PAL timed machines.
This beeing of course that I live in
the PAL area and have only access to
PAL machines. Furthermore, the PSID64
player (used to playback the tunes in
this project) might ignore the NTSC
flag bit set in the original SID file.
As the "TODO.TXT" in PSID64 states:
"compatibility mode for PAL SIDs on a
NTSC computer and vice versa.

I guess the development of PSID64
never included that, or was never
fully completed. What the result is
for the SOASC= is this: The NTSC
specifically timed tunes will sound
(in the MP3 version) a little bit
slower and also be pitched slightly
down (factor 1.038). This might also
interfere with the "songlengths.txt"
which is probably based on the
PAL/NTSC timing accordingly and
therefore some tunes will be in a
sense "wrong" in terms of the
AUTHENTIC factor!

So if a tune had a NTSC flag in it by
HVSC standard (like "Norman_Paul/
ForbiddenForest.sid") it will sound
slower and pitched down on a PAL
machine (or in the SOASC= MP3 version)

For a PAL specific tune, it would
then ofcourse be played faster and
pitched up instead if you did compare
it to your original NTSC machine or by
using SIDPLAY2 with the NTSC flag
speed set on.

However I tried "Sidplay64 v0.4" by
Glenn Rune Gallefoss / SHAPE / Blues
Muz' and that actually played NTSC
tunes different from what PSDI64 did,
so I'm not sure what effect I will let
this have on the current SOASC=
collection. If there are numerous
reports that certain tunes sound wrong
I might re-record them using the
Sidplay64 instead!

Q: "Why the 224Kbps, mono and CBR MP3
coding?

(I used LAME 3.97 Command line
version to convert the recorded wav
to MP3)

A: CBR is constant bit ratio which
means that a silent period in the MP3
have the same compression factor as  a
period with sound in it has. This
results in larger size MP3, but size
is NOT an issue here, and also it's
supported by older equipment (which
also represents the 224Kbps ratio)
such as DVD players,Car Stereo MP3
players, MP3 players both software and
hardware. It IS yesterday's
compression scheme for sure, but not
everybody are hip enough to follow
the bandwagon and be cool and buy all
the latest ipod MP3 players and do not
care about dowloading the latest MP3
player software. SOASC= is about
compability in probably all
environments and situations. MONO is
of course the only choice when
recording C64 music. C64 does NOT
play STEREO sound out of the
AUDIO/VIDEO connector and for the tech
freaks, the CHIP inside (6581 and
8580) has only ONE audio output.
Please remember, 3 VOICES OUTPUT
(as written in the C64 manual) is
not the same as STEREO SOUND OUTPUT,
and therfore what good will a STEREO
MP3 with the same audio in both
channels be any point to consider?

Continued in part 2