21 November 2023, 14:17 | #1 |
Registered User
Join Date: Mar 2017
Location: Stockholm, Sweden
Posts: 26
|
Paula FM synthesis
I remember hearing that Paula is capable of FM synthesis, or at least something similar, instead of just playing samples. I’m not talking about a soft synth but an actual feature in the chip.
Are there any examples of this being used? I guess it can’t be used in a mod but maybe in a demo or game so I can hear what it sounds like. I found this old thread talking about it, but without any examples. https://forum.amiga.org/index.php?topic=54117.0 |
21 November 2023, 14:26 | #2 |
Registered User
Join Date: Feb 2007
Location: Cologne / Germany
Posts: 213
|
Sonic Arranger was able to produce synthetic sounds. It was used by Matthias Steinwachs for Lionheart and Ambermoon.
|
21 November 2023, 14:27 | #3 |
Senior Member
Join Date: Jun 2001
Location: Germany
Posts: 1,645
|
But that is a soft synth.
Afaik, PAULA had no FM synthesis of any kind. |
21 November 2023, 14:28 | #4 | |
Defendit numerus
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 53
Posts: 4,468
|
Quote:
I didn't check if AM (volume) or FM (period) or both modulation is used, but for sure it use hardware modulation |
|
21 November 2023, 14:31 | #5 | |
Senior Member
Join Date: Jun 2001
Location: Germany
Posts: 1,645
|
Quote:
The question was not if PAULA can produce beeps on its own. It can, of course. |
|
21 November 2023, 14:36 | #6 | |
Defendit numerus
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 53
Posts: 4,468
|
Quote:
EDIT: of course it is very limited and inconvenient and eliminates one channel for each modulated channel (the reason why it is not used..), but technically it is a feasible synthesis. Listen carefully to the demo I linked. It doesn't do any kind of software modulation. Last edited by ross; 21 November 2023 at 14:45. |
|
21 November 2023, 14:44 | #7 |
Alien Bleed
Join Date: Aug 2022
Location: UK
Posts: 4,122
|
FM synthesis, or what most people think of when they hear the term, is actually phase modulation. The instantaneous phase of the carrier wave is modified by the modulator. There's no actual change of frequency, this is the emergent property of the phase modulation. The phase adjustment is linear - take the instantaneous amplitude of the modulator, multiply it by some modulation index (intensity) and add it to the phase input for the carrier. Both carrier and modulator are both operating at some fixed sample period in a digital implementation.
What Paula offers is Period Modulation. The period register for a channel can be fetched by a different channel and poked in. The two channels are not operating at the same period, unless by coincidence. The whole arrangement is very different, but it is a genuine hardware feature. Last edited by Karlos; 21 November 2023 at 20:15. |
21 November 2023, 14:47 | #8 |
Registered User
Join Date: Feb 2018
Location: Poland
Posts: 352
|
The uniformity of the results doesn't answer the question of whether it is capable of achieving this through its hardware features. I doubt that the 'PC speaker' has any registers to trigger that. Not to mention, it would need to have at least two channels (sources) to modulate between them. Do you think it really has these features? If not it is not the same. |
21 November 2023, 14:52 | #9 |
Defendit numerus
Join Date: Mar 2017
Location: Crossing the Rubicon
Age: 53
Posts: 4,468
|
|
21 November 2023, 17:02 | #10 | |
Registered User
Join Date: Jun 2008
Location: somewhere else
Posts: 511
|
Quote:
|
|
21 November 2023, 19:49 | #11 | |
Registered User
Join Date: Mar 2017
Location: Stockholm, Sweden
Posts: 26
|
Quote:
|
|
21 November 2023, 20:21 | #12 |
Registered User
Join Date: Mar 2022
Location: Birmingham, UK
Posts: 149
|
|
21 November 2023, 20:23 | #13 | |
Registered User
Join Date: Mar 2022
Location: Birmingham, UK
Posts: 149
|
Quote:
[ Show youtube player ] |
|
21 November 2023, 20:29 | #14 |
Alien Bleed
Join Date: Aug 2022
Location: UK
Posts: 4,122
|
I designed an alternative to 14-bit replay that instead uses Paula volume modulation to gain adjust a preprocessed 8 bit stream (generated from a 16-bit source) composed of frames where the volume of a frame is set by the modulator channel running at some fixed divisor. I mocked it up in software (encode/decode) but someone here - grond maybe? - actually implemented the replay proof of concept on hardware.
|
21 November 2023, 20:30 | #15 | |
Registered User
Join Date: Mar 2022
Location: Birmingham, UK
Posts: 149
|
Quote:
|
|
21 November 2023, 20:32 | #16 | |
Alien Bleed
Join Date: Aug 2022
Location: UK
Posts: 4,122
|
Quote:
https://github.com/0xABADCAFE/paula-hdr Last edited by Karlos; 21 November 2023 at 20:39. |
|
21 November 2023, 20:52 | #17 | |
Registered User
Join Date: Mar 2022
Location: Birmingham, UK
Posts: 149
|
Quote:
|
|
21 November 2023, 20:55 | #18 |
Alien Bleed
Join Date: Aug 2022
Location: UK
Posts: 4,122
|
Yeah, comparing. I considered delta encoding the 8-bit data and compressing that using more conventional techniques but that wasn't really the goal. Didn't stop me thinking about it though.
|
21 November 2023, 21:03 | #19 |
Moderator
Join Date: Nov 2004
Location: Eksjö / Sweden
Posts: 5,602
|
Yes, according to this definition by Wikipedia, and in hardware. Set up one channel to amplitude module another's frequency, and you're done. Reduces the number of channels by half, but 4 channels can be kept if the AM is done with the CPU, which is possible on all Amiga CPUs.
If by FM you mean "Sounds like Yamaha" (FM was their bid for a patentable synth engine), remember that the overall sound character is mostly up to the filter, and the waves and the treatment of them in the engine affects the overall sound minorly in comparison - to the point of even filter and circuitry artifacts being celebrated for giving a synth "a unique sound". My definition of FM is if that almost every sound sounds like a variation of a metallic bell if R is set to fade out fast, and it does the "FM Bass" fart, it's === Yamaha. --- The Amiga is a wonderful machine. <3 On it, rather uniquely, any synthesis and sample/wavetable/synth engine hybrid engines can be imagined with full support of the hardware. You're not limited to make something like what's already been. It obviously takes roughly the amount of work of coding a VA or other digital synthesis engine and minds knowledgeable of sound theory, which is why engines are not so advanced - e.g. Sonix, MusicLine, and not much else that has gained traction (FC and SID are as simple as Yamaha Y series, just waves+ADSR.) You also need someone tasked with programming lots of parameters for impressive instruments, and the synthesizer companies employed them. If the coder is supposed to do that work also, that's a lot of talent in, and hours out of, a select few key personnel. |
21 November 2023, 21:10 | #20 |
Alien Bleed
Join Date: Aug 2022
Location: UK
Posts: 4,122
|
FM (Phase modulation) can sound amazing. You just have to know how it works and how to wield it. It's not a very intuitive model, unlike additive or subtractive.
It gets especially interesting when you realise you don't have to be restricted to sine waves. Any periodic function, by definition, can be phase modulated. So, if you use triangle or saw waves carriers and a triangle for the modulator, you can create a sort of resonant sweep that you'd normally end up using filters for. Or you can replicate behaviours like oscillator sync and various other conceptually "subtractive" ideas. Many of the sound in this experiment were created using phase modulation of one form or another [ Show youtube player ] |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
Thread Tools | |
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Paula documents for a new Paula emulator library | MrSandMan | support.Hardware | 0 | 27 November 2022 06:27 |
Any scripts/tools to turn on Paula's AM/FM Channel Modulation? | Paulee_Bow | request.Apps | 23 | 30 July 2018 23:26 |
Kid Pix - Fujitsu FM Towns/FM Towns Marty | DamienD | HOL contributions | 0 | 16 March 2017 21:40 |
Speech Synthesis (SAY) | Dunny | Coders. General | 4 | 01 September 2011 21:22 |
Miggy, games and synthesis | Mr Softy | Amiga scene | 13 | 25 February 2003 23:51 |
|
|