Tuned FM with Modulator + Carrier

I have attempted to use dblues ringmod generator in two instances consisting of a modulator and carrier.
The goal was to generate a signal to modulate the carrier signal and maintain pitch ratio between the two.
The signal follower seemed like a perfect tool to modulate the target signal, not sure if anything else in the forum
uses this concept?

I can’t determine if this idea will work as expected due to my lack in knowledge of FM however i am hoping
someone can help me out here?

The modulator signal is sent to the carrier’s ring mod frequency via a signal follower - i guess this is where
we can control modulation depth by spreading min & max, the DC Offset controls amplitude and sensitivity can
be altered to better suit the type of modulator signal.

I think where i am stuck is that i don’t have anything in the modulator FX Chain to determine the pitch ratio between the modulator and carrier - i can’t even begin to image how this can be achieved? Is this even a possibility of conventional FM synthesis in Renoise?

I have attached two version however the recent version is more accurate to what i hope to achieve.

Without having checked your setups or their concept, there is one huge problem. The signal follower does not work sample accurate. Its max. timing resolution depends on Renoise’s ticks. That’s way too slow for accurate and usable FM.

Is there any way we can modulate an operand on the pitch modulator to change the rate of the modulator at precise ratios against the carrier?
This would obviously happen with predefined sample lengths though, would that be right?

Doh, why would you do that? Maybe in two days someone else gets the same idea and has the same questions.

The instrument envelopes indeed seem to work tick-independent. So that’d be the point to approach. But there’s no reliable way for us users atm to do that.

The sample lenght alone is not reliable as a calculation source, because the sample could contain multiple cycles, cut cycles at its start, end or in between, frequency changes, etc… Accurate FM depends on the frequency contained and of course also played with the sample. In the end everything is fine, as long as your sample is tuned right, no matter how long it is. The rest is simple logics.

I get what you’re saying… Could a formula work this math out for us and send the signal to a carrier on another fx chain? (since the signal follower is useless in this situation).
My guess is there would have to be a formula on the carrier’s fx chain to recalculate the received values in order to modulate the carrier at certain ratios?

The only reason why i had hope in what i have done so far is because i was able to modulate a triangle wave with another triangle wave as a modulator (using the signal follower) and the results were
just as expected with any conventional fm synth with one operator modulating the other.

How does tick resolution compare to sample resolution? 256 ticks per line? How many samples per line is determined by?

First of all, all Meta-Devices share the same fate. They’re all timed by ticks. Or let’s say at least their meta-in- and output is. That also goes for the formula device. So this wouldn’t change much.

Uhm, on what frequencies of carrier and modulator? I actually doubt, this works on higher frequencies.

The reference note/tone A4 has a frequency of 440Hz. That means 440 (single-) wave cycles per second. To achieve the highest frequency on 44.1 kHz you need two samples (the shortest possible cycle). So 1Hz with 44.1kHz then has 88200 samples. One cycle of the 440Hz tone then would have a lenght of about 200 samples. [EDIT: Confused a few things myself here.] A single 440Hz cycle has a lenght of ~ 100 samples at 44.1kHz sample rate. Why explain easy, when you can make it look complicated?

Another try. Actually you only have to compare 44.100 samples per second to the ticks you can achieve at the same time. Let’s say we have some house track with 128bpm. That’s 2,1333 beats per second. With 4 lines per beat, that’d mean 8,5333 lines per second. Multiplied with the ticks per line we get 2.184,5333 ticks and 2.184,5333 samples per second, that can be tracked.

128 / 60 = 2,1333 * 4 = 8,5333 * 256 = 2184,5333 sample rate == a max frequency of 1092Hz

Doubling the LPB means doubling the managable sample rate.

The Signal Follower imo is not suitable for the whole thing anyway, since it has some very own timing issues, when running in multi-CPU environments. Well, at least it had in 2.8. Haven’t checked this in 3.0 yet.

In Renoise 3.0, instrument envelopes are beat/msecs timed. Ticks do not have influence on the envelopes anylonger (unless your instrument is still in compatibility mode)

Yeah, fine so far. If there wasn’t that bad thing with triggering those envelopes (/modulations) by meta-device. What was actually the reason for taking the ability for FM modulation out again. When I remember right, you told it was available during the alpha-testing!? Though, anyway with basic waveforms only, I guess.

I doubt i said that, because that never was an alpha feature (it was heavily discussed and promoted to get it in during late alpha stages though but there simply was no more time to add in any specific extra large feature). There was perhaps something taken out, but i currently don’t remember at this late hour.

Nope, there never was such a thing. A bit of talk, that was all (avoiding a design which would prevent such a step later on).

Hm, I was totally sure someone of the team told, FM was in the alpha for a while. Maybe I got something wrong. :)