Chipsynth C64 is an emulation of the SID so good, it can replace hardware
cdm.link
cdm.link
This video shows some insight into the development process: https://www.youtube.com/watch?app=desktop&v=VLxTHYGLKY0
That was done by using 4bit sample data and using those values to set the audio level.
edit: my bad, MacOS or Windows only...
There are countless of synth engines, from basic lfos and filters, to modelling circuits.
This doesn't have any special sauce.
Is there scientific data supporting the verbal "it's really good" and "we did lots of research" claims?
Such as mdfourier testing and comparison with the original chips, or equivalent scientific scrutiny and comparison of the respective outputs?
The claims may well be true, but the greater the claim to merit, the more robust the supporting evidence should be.
[Answer follows: ]
Yes there does appear to be some, at approx 10m45sec of this Youtube video which is contained within the OP link. https://www.youtube.com/watch?v=pePq68HaI7M
As for being scientifically correct, Commodore was infamous for cutting corners so resistances (and prob other parts of fabrication) varied wildly so at best you can probably compare to specific chips (even if families of fabrication are closer,esp w.r.t to 8580 vs 6581 behaviours).
Read the article again in that light (as those details are alluded to) or look at the analysis of the C-64 graphics chip colors (There is a nugget in the response from the Sid-chip designer at the bottom of this other article about Commodore inner workings).
It would be really neat if Chipsynth were capable of emulating those different resistances, to tweak them a bit to get a 'warmer' sound or something different, to allow further tweaking of the sound. I'm not sure if Chipsynth is emulating at the silicon gate level, or the analog circuits within the SID. Would be cool if it were.
I can't follow that. Wouldn't it just lead to a lower amplitude sine wave? Where does the phase shift come from? My visual imagination is failing me here, mostly I don't get why the sine wave would shift forward or backwards if all that changes if the amplitude because that's symmetrical.
Or you could just have some toggle to switch from and offer all of their behaviors.
Super impressive tracker and emulator for many different 8 bit synth chips.
As a personal project I'm also embarking on a 4x AY-3-8910 chip synth all hooked up to as esp32-s3 for usb midi
I already have the chips. 10x AY from AliExpress for £7 and they turned out to be the real deal.
It does sound pretty good. Not sure it will see much use outside of demoscene musicians though. I would love to be hearing more c64 music in my life though, glad Chipsynth exists.
Now what am I going to do with the half dozen SID chips I've been hoarding for the last 30 years?
(I think the Sidstation is the only synth I regret selling, well maybe together with the Jupiter-6)
Machinae Supremacy comes to mind [0]. I esp. selected a song which their SID tunes are very audible. Normally they do it way more subtly.
Will we have to wait another 15 years for the ZX Spectrum version? :)
An overview what is new would have been nice. I think at least the UI looks a bit smoother buy otherwise it is hard to tell if an upgrade is worth it.
they say they're selling deep Sid chip emulation, but for what platform and for what formats? if I knew, I'd either be all over it, or wait until they supported what I was after (in my case, AU synth on macos), but without any information on what I'd be buying, it's a very hard sell.
> Today, Plogue is launching chipsynth C64, an AAX/AU/VST3/CLAP plug-in recreation
It's also discussed in the manual: https://s3.amazonaws.com/chipsynth/C64_manual.pdf
No sir I'll stick with my MSSIAH.
IIRC, SID has no real mute on the outputs, so oscillators and output stage is always active. This, in turn, injects its legendary background noise to the generated sound regardless of there's a wave being generated or not.
Moreover, the distortion itself is coming from the internal noise of the die itself, as a secondary effect of being an integrated circuit, plus its fabrication technology.
As a result, the sound of a SID chip is result of its design plus the secondary effects introduced because of its fabrication process.
This is what makes simulating a SID very hard. You need to characterize and formulate these secondary effects and inject them to your pure generation (design) simulation real-time, without much processing overhead.
This is really hard. Maybe not in the math department, but integration, coding, optimization and stabilization department.
P.S.: This is why Machinae Supremacy started making music with real SID chips.
But, that gave it character, and people grew to love that sound. Maybe it was a fluke, maybe nostalgia, maybe people at Commodore had a good ear when tweaking the circuit and made something sound good out of the little budget they had because they knew they couldn't go for hi-fi (that would actually be clever).
This is a bit like the TB-303, a terrible bass synthesizer that ended up revolutionizing electronic music. Or overdriven guitar amps that became the staple of the hard-rock/metal genre.
In the words of the engineer that designed the SID chip, Bob Yannes who founded the synthesizer company Ensoniq after he left Commodore in 1982:
> “Actually, I was an electronic music hobbyist before I started working for MOS Technology (one of Commodore's chip divisions at the time) and before I knew anything at all about VLSI chip design. One of the reasons I was hired was my knowledge of music synthesis was deemed valuable for future MOS/Commodore products. When I designed the SID chip, I was attempting to create a single-chip synthesizer voice which hopefully would find it's way into polyphonic/polytimbral synthesizers.”
> “The SID chip was my first attempt at a phase-accumulating oscillator, which is the heart of all wavetable synthesis systems. Due to time constraints, the oscillators in SID were not multiplexed, therefore they took up a lot of chip area, constraining the number of voices I could fit on a chip. All ENSONIQ sound chips use a multiplexed oscillator which allows us to produce at least 32 voices per chip. Aside from that, little else of SID is to be found in our designs, which more closely resemble the Mountain Computer sound card for the Apple II (the basis of the Alpha Syntauri system). The DOC I chip (used in the Mirage and ESQ-1) was modeled on this sound card. Our current designs, which include waveform interpolation, digital filters and digital effects are new designs that aren't really based on anything other than our imaginations.”
> “The issue wasn't budget, it was development time and chip size constraints. The design/prototype/debug/production schedule of the SID chip, VIC II chip and Commodore 64 were incredibly tight (some would say impossibly tight)--we did things faster than Commodore had ever done before and were never able to repeat after! If I had had more time, I would have developed a proper MOS op-amp which would have eliminated the signal leakage which occurred when the volume of the voice was supposed to be zero. This lead to poor signal-to-noise ratio, although it could be dealt with by stopping the oscillator. It would also have greatly improved the filter, particularly in achieving high resonance. I originally planned to have an exponential look-up table to provide a direct translation for the equal-tempered scale, but it took up too much silicon and it was easy enough to do in software anyway.”
https://web.archive.org/web/20070222065716/http://stud1.tuwi...
While you can theoretically build the same analog circuitry using discrete N-channel MOSFETs, it will not capture the tone of the original.
In particular the "operational amplifiers" used in the design were very simplistic things built out of just a handful of transistors and are very non-linear devices.
It is possible to build a circuit that behaves similarly but it won't sound the same.