FM on non-FM chips

General discussion about tracking, help and support.
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FM on non-FM chips

Postby SusiKette » Thu Aug 06, 2020 11:29 am

I did a small experiment and figured that you can do limited FM on non FM chips by applying very fast vibrato to them (although technically FM chips modulate phase instead of pitch, it still leads to the same result). I used the pitch even to achieve this. This is useful in note attacks to create brass like attack and for making SFX. There are many more applications on how these can be used, the attachments show a few examples. This has to be done at max speed, otherwise it's too slow to create FM. "trumpet" and "pluck" are very subtle effects and "drop" uses more extreme application of FM.

Original tracks for the attachments:

I noticed that when you use this, some pitch effects become inconsistent. Sometimes they work and sometimes they don't. Most notably Qxx and Rxx effects are affected. Using 'relative' pitch mode makes less likely for these pitch effects to not work.

Considering the freedom N163 chip gives you with wavetables using FM probably will allow you to create some really cool sound (still have to test that). You can also get slight RM if you modulate the volume of an instrument.

Have you used this method on any of your songs/covers? Feel free to post .ftm files if you figure out a nice way to use this effect. I want to see what you can come up with.
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*Please make sure you are using FamiTracker v0.5 when trying to open my ftm files*


Posts: 22
Joined: Mon Nov 09, 2015 7:08 pm

Re: FM on non-FM chips

Postby GlidingSoul » Fri Aug 14, 2020 12:37 pm

The FDS chip lets you perform sorta-FM effects using very fast vibrato. You can also go to Tracker > Playback Rate and set it to 400 Hz (1000 Hz in version 0.5 beta).

I've attached a module to demonstrate this.
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