Music Production > MilkyTracker Support

Samples automatically finetuned?

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raina:
AFAIR 8363 is also the initial value for sample finetune in Scream Tracker 3.

jimee:
May I make a supposition?
8363Hz was the finest C that Paula could do.

The frequency of C is about 523.25Hz... Upper octaves are 1046.5, 2093, 4186, 8372Hz ...

So, if we have a sample consisting of 16 bytes, and we play it at 8372Hz, we ear a C.

Now, we have an Amiga's dsp called "Paula", able to replay that sample at some rates defined by the time between each byte (the period), and the time unit is "couples of CPU clock ticks". That dsp is clocked by a quartz at exaclty 7159090Hz (in the NTSC version). To rate at 8372Hz, we need to wait 7159090/8372=855.1 ticks between each byte. Once that number rounded to the unit (nearest even number is 856), the real rate played is :
7159090/856 = 8363Hz!

If trackers was born on a PAL amiga, we'd have chosen a period of 848 ticks, making a rate of 7093790/848=8365Hz... Instead, PAL amigas inherited the 856 period, and played a mistuned C at 8287Hz.

luke:
WOW! Thanks everyone. that is really interesting. you guys got knowledge!! i need to learn more. i guess i should just ignore it in terms of making music as long as everything is staying in time and in tune. so any C is always a teency bit out of tune in milkytracker but its such a small amount its almost impossible to hear.....(i think, lol!!) and loading the xm into modplug would correct that anyways i guess... thanks again, nice one...i love this shit!!

luke:
Just to clarify.....8372 divided by 16 (bytes) = 523.25Hz so milkytracker plays a perfect C.
I have to admit Im a little baffled here  :o !!!

eightbitbubsy:
Sorry for bumping this thread, but I have some stuff to add to this topic...


--- Quote from: jimee on August 30, 2009, 23:19:12 ---8363Hz was the finest C that Paula could do.

--- End quote ---
8373 should be possible and is closer to 8372 than 8363.

7159090Hz/855per = 8373Hz (NTSC)
7093790Hz/847per = 8373Hz (PAL)


--- Quote from: jimee on August 30, 2009, 23:19:12 ---To rate at 8372Hz, we need to wait 7159090/8372=855.1 ticks between each byte. Once that number rounded to the unit (nearest even number is 856), the real rate played is :
7159090/856 = 8363Hz!

--- End quote ---
Rounded to the nearest even number? There are both odd and even numbers in the ProTracker/Ultimate Soundtracker period table. This is what makes me believe 8373Hz is possible (NTSC: 855 - PAL: 847), do you have any source for this?

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