[HN Gopher] Chipsynth C64 is an emulation of the SID so good, it...
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       Chipsynth C64 is an emulation of the SID so good, it can replace
       hardware
        
       Author : adunk
       Score  : 82 points
       Date   : 2023-12-07 13:53 UTC (9 hours ago)
        
 (HTM) web link (cdm.link)
 (TXT) w3m dump (cdm.link)
        
       | leptons wrote:
       | Wow lots of hype about this out today - it showed up twice in my
       | youtube feed.
       | 
       | 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?
        
         | steve1977 wrote:
         | Let me know if you want to get rid of them ;)
         | 
         | (I think the Sidstation is the only synth I regret selling,
         | well maybe together with the Jupiter-6)
        
         | bayindirh wrote:
         | There are bands which use SID chips/sound in their music, and
         | they are not demoscene musicians.
         | 
         | 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.
         | 
         | [0]: https://www.youtube.com/watch?v=oFVnwR5C07I
        
       | soundsubs wrote:
       | I bought it yesterday and I'm loving it. It's really good! AND NO
       | SAMPLES! I want to support developers like this who make
       | something out of bounds with math instead of same old same old
       | (samples, kontakt player, half done synth engine) I appreciate
       | the level of detail and effort he put into this emulation, and it
       | ALMOST cures my lust for a THERAPSID mk3.
        
         | OnlyMortal wrote:
         | No samples? Damn.
         | 
         | That was done by using 4bit sample data and using those values
         | to set the audio level.
        
         | oidar wrote:
         | How CPU intensive is it?
        
         | trinsic2 wrote:
         | What do you need to run this?
        
       | nickt wrote:
       | 15 years in the making - incredible effort guys.
       | 
       | Will we have to wait another 15 years for the ZX Spectrum
       | version? :)
        
         | wdfx wrote:
         | AY emulation exists in https://github.com/tildearrow/furnace
        
       | wdfx wrote:
       | I recently came across https://github.com/tildearrow/furnace
       | 
       | 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
        
         | wdfx wrote:
         | More info about my synth build idea
         | https://github.com/tildearrow/furnace/discussions/1605
         | 
         | I already have the chips. 10x AY from AliExpress for PS7 and
         | they turned out to be the real deal.
        
       | mrob wrote:
       | This appears to be proprietary software. If you prefer Free
       | Software, reSID also provides very good SID emulation:
       | 
       | https://en.wikipedia.org/wiki/ReSID
        
       | radarsat1 wrote:
       | Although its sound is legendary, I can imagine it's not that
       | complicated a chip. Had anyone ever tried to replicate it with
       | discrete components?
        
         | bayindirh wrote:
         | The sound of SID comes from its architectural decisions and how
         | the die behaves as an integrated circuit.
         | 
         | 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.
        
           | whizzter wrote:
           | In addition to this (and this is a huge part of what makes it
           | hard to emulate) is that parts of the chip works in the
           | analogue domain, that combined with the added
           | outputs/noise/etc is what makes for the richness to be so
           | hard to emulate.
        
             | bayindirh wrote:
             | You're right. I forgot that some parts of SID is actually
             | analog. Thanks for the addendum.
        
       | crtified wrote:
       | [see me answering my own question, at bottom of comment]
       | 
       | 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
        
         | whizzter wrote:
         | Skimming the article, it does seem like they've built a model
         | (there has been much work over the years on opensource
         | emulators,etc so the basic operation is fairly well researched)
         | and then sampled a bunch of real chips to find variances and
         | behaviours to get profiles that comes close to the real ones.
         | 
         | 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).
         | 
         | http://unusedino.de/ec64/technical/misc/vic656x/colors/
        
           | leptons wrote:
           | >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).
           | 
           | 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.
        
       | H1Supreme wrote:
       | I have the Chipsynth MD, which is a Sega Mega Drive (aka Genesis)
       | based synth from Plogue and it's one of my favorite plug-in
       | synths. It's pretty remarkable how much it nails the sounds from
       | those games.
       | 
       | This video shows some insight into the development process:
       | https://www.youtube.com/watch?app=desktop&v=VLxTHYGLKY0
        
         | trinsic2 wrote:
         | Wow! Some really cool sounds you can make with this setup
        
       | MenhirMike wrote:
       | The Plogue stuff is really high quality, though I wonder how it
       | compares to their own chipsounds which already did the SID - I
       | guess it's more all-encompassing of the different SID variants?
       | Anyway, will give it a look later, this is neat! (Good to see
       | they're explicitly calling out PWM, that's one of the key parts
       | that made so much of the sound work so well on the machine)
        
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       (page generated 2023-12-07 23:00 UTC)