ChipMusic.org - NES pitch frequencies in famitracker, and how to retune for accuracy

Re: NES pitch frequencies in famitracker, and how to retune for accuracy

2010-02-17T01:40:58Z

tanx!

Re: NES pitch frequencies in famitracker, and how to retune for accuracy

2010-02-01T13:14:21Z

I've had many heartfelt problems with pitch values through out the years and the only thing that soothed my pitch burn was just trial and error and eventually hitting the key I was aiming for. Thanks for this table, Bucks! I hope JSR does get around to fixing some of these pitch incorrections!

Re: NES pitch frequencies in famitracker, and how to retune for accuracy

2010-01-31T17:42:15Z

Maybe someone could tell JSR about this so it can be included in future versions?

Re: NES pitch frequencies in famitracker, and how to retune for accuracy

2010-01-31T17:31:06Z

It's code dependent.

tepples posted a fix for this on nesdev;

http://nesdev.parodius.com/bbs/viewtopic.php?t=502

I use his code to generate my pitch tables too and they're pretty spot on.

Of course, unless you are able to build FT it's not much use

Re: NES pitch frequencies in famitracker, and how to retune for accuracy

2010-01-23T20:18:55Z

I'm under the impression that it's an idiosyncrasy of the sound engine and not actually a bug. Like there's probably some sort of equation or maths above my head that determine the pitches, and the more out-of-tune notes are a casualty of that. I think I recall hearing high pitched triangle melodies in games that were both in tune or out of tune, so it's probably dependent on the underlying code.

Re: NES pitch frequencies in famitracker, and how to retune for accuracy

2010-01-23T16:45:13Z

So is this the result of famitracker bugs? Or hardware weirdness? Could JSR fix it?

NES pitch frequencies in famitracker, and how to retune for accuracy

2010-01-23T15:12:16Z

I posted this over at 8bc some months back, but figured I'd do a repost. I'll be doing that to a couple things I put some work into, so I apologize in advance for the redundancy! Maybe this'll be helpful to anyone new in this community... that and I feel safer having this on more than one forum.

--
The triangle gets noticeably sharp at some higher pitches, and I was able to use the fine tune, or PXX, effect to get it much closer for certain notes. I figured I'd look at all the notes and make a table to use as a reference.

Table of Famitracker pitch values

DF = Desired Frequency. What the pitch "should" be in an equal tempered scale.
AF = Achieved Frequency. This is what the NES produces with a normal note in FT.
Effect = The PXX effect used.
EF = Effect Frequency. This is what the note turns out as with the effect applied.

Where ever you see a PXX effect is somewhere you can obtain a closer, more accurate pitch (asides from a couple of the triangle pitches which come out as equally out of tune, in the other direction). If there is no PXX effect, then that's as close as you're getting with FT.

Observations:
-Most pitches for the pulse waves are varying amounts of sharp. Most are by a pretty subtle amount though, so while you can get some notes closer on the flat side, there's no real need for fine-tuning.
-Triangle pitches can vary between flat and sharp. Notes like D#6 and A#6 are very sharp by default, but you can get them near perfect by changing them. Also A-1 can be altered to be perfect.
-There is never an instance where pitching more than one value above (P81) or below (P7F) gets you closer to an equal tempered pitch. Nothing is quite *that* far off.