[HN Gopher] Reverse-engineering the Yamaha DX7 synthesizer's sou...
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Reverse-engineering the Yamaha DX7 synthesizer's sound chip from
die photos
Author : picture
Score : 252 points
Date : 2021-11-13 17:18 UTC (5 hours ago)
(HTM) web link (www.righto.com)
(TXT) w3m dump (www.righto.com)
| dboreham wrote:
| Shout out for the DX9 which was quite a bit less expensive,
| bringing it within reach of a wider market. My brother had one
| when we were in high school.
| Waterluvian wrote:
| On the topic of synth chips, does anyone have any good resource
| talking about why those big retro synths still exist?
|
| There's got to be a good reason I simply don't understand for why
| a computer cannot replicate everything those massive pieces of
| furniture do.
|
| The one thing I concluded is that their interface, with hundreds
| of knobs and potentiometers must be very nice to interact with.
| But can they not just house a computer inside?
|
| I guess my curiosity and ignorance boils down to: why can't
| computers generate all the kinds of signals that these big synths
| do?
|
| Edit: a bulk thank you for all these helpful responses.
| DennisP wrote:
| In principle they can, in practice the limitations on
| processing power have caused the sounds they produce to lack
| the richness of analog. They're getting better though.
|
| The thing about analog is that you get a lot of random
| variation in the waveforms. A naive computer implementation
| will lack that variation. A better one will purposely add
| particular random variations. The really good ones, like Diva
| (which runs on a regular computer), will run SPICE-style
| simulations of the actual analog circuitry, but running that at
| full fidelity is still pretty processor-intensive.
|
| There are lots digital hardware synths that emulate analog.
| There are also hybrids, like Novation's Summit and Peak. These
| start with digital sound generation, but using FPGA to run at a
| much higher sample rate (24 MHz instead of the typical 48 to 96
| kHz). Then they convert to an analog signal that runs through
| analog filters, then they convert back to digital for effects
| (reverb and such). The advantage of starting with digital here
| is that it can start with different waveforms than the ones
| easily generated by analog circuits.
|
| Further muddying the waters, modern analog synths have
| components with a lot more precision than in the old days, so
| they _also_ lack some of the random variation of the old stuff.
| That 's great for staying in tune, but now synths like the OB6,
| which is pure analog, have added "vintage" features which
| artificially add the variations again.
| mrob wrote:
| Modern software simulations are very accurate for
| conventional VCO-to-VCA-to-VCF type sounds, but struggle with
| audio frequency modulation of control voltages. Aaron
| Lanterman includes an example of this in his excellent
| lecture series on analog synthesis:
|
| https://www.youtube.com/watch?v=GZz8PJCfK1c&t=452s
| DennisP wrote:
| That looks like a really interesting course.
| jb1991 wrote:
| There is quite a big difference between a digital sound and an
| analog sound, and even among digital sounds, there is a big
| difference between a software program making sounds and a
| digital hardware circuit that is architected specifically for
| making particular types of sounds.
| Waterluvian wrote:
| Thanks! What might I search for to understand this detectable
| and quantifiable difference (vs. Monster cable style
| subjective feelings about sound)?
| 323 wrote:
| It's mostly that hardware makers invested more time and
| money into the algorithms to make them more pleasantly
| sounding. Many software synths are one-man projects which
| has to do it all (DSP, UI, ...)
|
| Hardware makers also have proprietary institutional
| knowledge, since you can have a couple persons who
| researched synthesis methods for 10 years.
|
| They also work with users to tweak the sound and interface
| to perfection.
| lvl100 wrote:
| If you look at DAW and plug-in offerings they have a lot of
| these in digital format. But you're right about having actual
| physical controls is very different. And I do think there will
| be a completely custom audio interface/keyboard/synth in the
| next couple of years (this is a side project of mine).
| rotexo wrote:
| I don't have any resources for you, but I will say that there
| are a lot of synth emulations out there (for instance, google
| "dx7 vst"). Developers might be more or less obsessive about
| emulating the particular quirks of different hardware synths,
| but I can't say how significant those details are. I guess it
| comes down to the listener's ears.
|
| Some people like having vintage synths because they are
| collectors, and some like the workflow surrounding them (ie,
| the big front panel of knobs and faders you allude to, or the
| simplicity of plugging in audio and/or control voltage and/or
| midi cables).
| martyvis wrote:
| I listened to this "shootout" video only two days ago. The
| different ones tested here all have their quirks. (I've been
| playing with Dexed as it has all the original features and is
| free). https://youtu.be/vMvGk_fcIo8
| 323 wrote:
| One factor is analysis paralysis. On a computer you can have
| 100 different software synths, which can be daunting.
|
| Having 2-3 quality hardware synths can force you to get things
| done and not get lost in minutiae.
|
| Of course, there are also modern producers which are very
| effective with software only.
| spookthesunset wrote:
| That is one of the biggest hurdles I have whenever I attempt
| to play around with fancy synths... lots and lots of options.
| Very easy to get completely lost in the weeds.
| detaro wrote:
| Few points:
|
| a) people _like_ having the original thing, even if it can be
| replicated. (I think this generalizes fairly far across musical
| instruments, old ones are always coveted by some, and into many
| different topics)
|
| b) Limitations of the circuitry etc that affect the sound can
| be surprisingly hard to precisely simulate. For cult machines
| that's probably something someone has done, but it's a lot of
| work.
|
| c) as you said, physical interfaces are important, as are the
| restrictions of what an instrument _can 't_ do the guide where
| people go with it
|
| d) people will fight tooth and nail about b) and if a specific
| simulation is _good_ or not - and often you can assume that the
| range of how the originals sound is actually also quite large
| (especially now, with the components having aged a few
| decades), so you 'll always find someone who is sure the
| software doesn't sound exactly like the one specific device
| they compare it to.
| lewispollard wrote:
| For digital synths, yeah they can be fully emulated afaik. With
| the actual hardware unit, you get the knobs and keys, sure, but
| it's basically an embedded device, the OS and synth functions
| are tightly integrated. Which means nothing competing for the
| scheduler, latency practically 0. Plus they come with all the
| standard inputs and outputs needed for performance over a PA.
| By comparison a laptop is a bit of a liability. Who knows when
| some system service is gonna activate and add latency, or cause
| a freeze, or stall the audio driver, or something. Plus you
| then have to lug around all these adaptors and cables and
| external devices, for the I/O that you need that isn't built
| into a laptop. If you're a performance artist anyway, it's not
| as big a deal in the studio.
|
| For analog synths, well they can also be emulated quite
| accurately, but the way they produce sound is just
| fundamentally different to digital synthesis. They're directly
| manipulating the voltage of current to get oscillation, and
| then manipulate that signal to drive the speaker and produce
| sound. This process can be emulated but it doesn't produce the
| same output in a physical sense. It's questionable whether a
| typical audience would notice the difference I guess, but
| there's something quite raw and visceral about using an analog
| synth.
| post-it wrote:
| I'm not a sound engineer or anything, but I've noticed that
| dedicated audio equipment is _really fast_ - there 's always
| zero perceptible latency, even in a complex system that uses a
| bunch of different boards connected together. It's hard to make
| very low-latency software because of all the layers of
| abstraction between applications and the OS and various
| hardware buffers.
| jacquesm wrote:
| And software buffers! Those are usually much worse than the
| hardware ones.
| aspenmayer wrote:
| For a look at what it takes for a clean room reimplementation
| of this same synth:
|
| https://www.youtube.com/watch?v=XJ97iXQrqzw
| al2o3cr wrote:
| But can they not just house a computer inside?
|
| A lot of modern modules _do_ just have a computer inside - for
| an open-source example, many of the Mutable Instruments modules
| use AVR or STM32 controllers:
|
| https://github.com/pichenettes/eurorack
| squarefoot wrote:
| Electronic musical instruments, especially from the mid-80s on,
| make heavy use of customized and of course undocumented ICs, thus
| revealing their inner workings is of immense value for emulation
| purpose when the original instruments are either unobtanium or
| too costly for normal people to purchase. Also, should one day
| technology allow small run production of chips at home, sort of
| 3D printing silicon, it might be worth having a library of
| interesting chips to replicate for fun and/or to repair old
| instruments.
| djmips wrote:
| FPGA kinda almost works like that for digital projects with
| some light analog, that is you can convert analog processes to
| a digital form and output using Delta Sigma modulation.
| vbezhenar wrote:
| Is accessible FPGA powerful enough for something like Intel
| 8080?
| nyanpasu64 wrote:
| Consumer-purchasable FPGAs can emulate systems up to the
| SNES, and soon PS1
| (https://www.youtube.com/watch?v=bo1GgF6X-7A).
| https://www.retrorgb.com/mister.html one requires a
| DE10-Nano ($176.50) and needs a $60 128MB RAM module for
| most consoles.
| smoldesu wrote:
| Behringer's redesign of the 3340VCO has been huge for bringing
| cheap analog equipment to the masses. I own their Neutron,
| which is a semimod kinda like the Mother-32 but with a few
| bonuses and more patch points. It's seriously impressive for
| being a home-grown instrument at a sub-300-dollar price point,
| and I'd probably choose it over most other instruments in it's
| price class like the Monologue or UNO.
| ixfo wrote:
| Behringer's goal has always been to make stuff cheap enough
| that people can afford. Which is noble, except they do this
| entirely by ripping off other people's R&D and undercutting
| lots of people including smaller players.
|
| Also Uli Behringer himself is completely mad and appears to
| be pretty chill with antisemitism.
| https://www.gearnews.com/uli-behringer-responds-to-the-
| corks...
|
| tl;dr don't support Behringer, please.
| joecool1029 wrote:
| The ripping off of designs stuff is lame and enough to
| avoid but the 'antisemitism' smear comes from a poorly
| thought out gag video[1] that's honestly more offensive to
| the French if anything.
|
| [1] https://m.youtube.com/watch?v=7mgsIjQXZ7c
| liotier wrote:
| The Neutron is an exception - it is one of the few
| Behringer products that is an original creation and not a
| cheap clone of a reputed instrument. Also, there is nothing
| like it anywhere near that price range. I bought a Neutron,
| but I would feel dirty buying a clone of something that is
| still in production.
|
| Some background, for those who don't yet know the
| controversy surrounding Behringer clones:
| https://www.factmag.com/2017/04/08/behringer-minimoog-
| synth-...
| smoldesu wrote:
| Yep. I don't feel bad about them ripping off the Moog
| Model D when your only other option is to buy an
| authentic recreation at 10-15x the price.
| comboy wrote:
| Or downloading official Model D app made by Moog for
| $14.99
|
| https://apps.apple.com/us/app/minimoog-model-d-
| synthesizer/i...
|
| It sounds amazing.
| smoldesu wrote:
| That's not an analogue device though, so it's not a like
| comparison. Anyone can build a digital Model D these
| days, but mass-producing a piece of discontinued hardware
| at less than a tenth of the price is a different ball
| game altogether.
| smoldesu wrote:
| I don't really care about the politics of it, I'm just
| shopping for cheap gear and they're the only ones pushing
| out quality synths at affordable prices. If Moog or Korg
| were actually competing in the low-end business there might
| be a different story, but I couldn't care less when
| Behringer's stuff sounds so good.
| multjoy wrote:
| Back in the 00's, I toured as a sound engineer. Behringer
| turned up in all manner of touring racks.
| uxp100 wrote:
| This is not really a competitor to the behringer semi
| modular analog synths that upset some people, but an
| inexpensive synth I'd highly recommend is the Arturia
| Microfreak.
| deeblering4 wrote:
| It sounds good because they are ripping designs off and
| mass producing clones for cheap.
|
| In terms of build quality and feel there is a huge
| difference between a Moog or Korg and a Behringer.
|
| Behringer gear is made with the absolute cheapest
| components available and that becomes obvious as soon as
| you touch it.
| genewitch wrote:
| So they're the MFJ of the audio world?
|
| I'm fine with that.
| nr2x wrote:
| They also routinely go after journalists and critics, in at
| least one case by using antisemitic tropes (as you noted).
| kennywinker wrote:
| This is maybe a little outside the scope of your article, but
| I've read about the DX7's log2 based sine wavetables in the past,
| and it makes sense from a math standpoint (log2(x) + log2(y) =
| log2(x*y)). However, I find it confusing when I go to try to
| replicate it. My understanding is that these are NOT floating
| point numbers. In which case the output would be in the 8bit
| range of (0-257) or -127 to +127 if we're using signed values.
|
| So assuming I want to represent a signal value of 127 (i.e.
| sin(t) = 127) using base 2 logs, I punch this into my calculator
| and i get log2(127) = 6.9886. But that's not what's going to be
| stored in the signal LUT since it's a floating point number.
|
| I think I'm probably missing something obvious, but any
| clarification would be amazing.
| thegardengnome wrote:
| What danachow said makes sense to me. Under the "Logarithms and
| exponential" heading, it says the operator chip uses an
| exponential look-up room to convert this value back to a linear
| value. "This value" here refers to the output of log2(x*y). So
| I think it's implied that yes, the log2 calculation will yield
| a floating point number, but that floating point number will be
| converted back to a phase increment value that corresponds to
| the LUT. This is my shallow understanding of things
| kens wrote:
| The numbers are bigger than 8 bits. I'm still figuring out the
| exact sizes, but it looks like the phase values are 23 bits and
| the table lookups are 12 bits. There are also numbers that are
| sort of floating point, with the value shifted by a few bits
| depending on how large it is. (This is one reason that DX7
| emulators don't exactly match the DX7, because the number of
| bits used isn't standard.)
| danachow wrote:
| 6.9886 is not a floating point number - it's just a number.
| Floating point is but one representation for approximation of
| real numbers, so called fixed point is another one. Having said
| that I believe the DX7 does use a floating point representation
| internally since floating point addition can be done with adds
| and bit shifts - both easy things to do in hardware.
| jimktrains2 wrote:
| Maybe it's stored as a fixed point? 4 bits for the signed whole
| number portion and 4 for the fractional part?
| kennywinker wrote:
| I don't think that's enough precision? I.e. if you only have
| -7 to +7 range for the whole number and 0-16 for the
| fractional portion, how do you represent 6.9886? 1000/16
| means increments of 62.5 so the closest numbers we can
| represent are either 7.000 or 6.9375 - but 6.93xx overlaps
| with log2(126) = 6.9773 and 7.000 overlaps with log2(128)
| danachow wrote:
| It's not 8 bits. Most of the Yamaha chips seem to use 16
| bits internally in 8.8 format (based on Raph Leviens work).
| Different models of Yamaha chips had different DAC setups,
| but on the DX7 the representation was 12.3 floating point -
| which I think was converted from the internal log scale
| fixed point to linear scale via a lookup table. So while
| the DX7 chips technically use both floating and fixed point
| it probably does all arithmetic in fixed point.
| kens wrote:
| Author here if anyone has questions...
| GhettoComputers wrote:
| Amazing blog, glad I found it and the other articles look great
| too! Very interesting history of computing.
|
| Can you use an arbitrary waveform generator to make these
| sounds accurate or differences nonexistent?
|
| Do you think that good audio can be "solved"? I've heard of
| Harmon tuning and people's preference for it, and how good
| speakers are all tuned the same but high end headphones don't.
| I remember this person who knew electronic design destroying
| the credibility of head-fi. https://nwavguy.blogspot.com/ what
| do you think of forums like audio science and his findings?
| kens wrote:
| Well, you could feed the right digital values into the
| arbitrary waveform generator, but you have the problem of how
| to generate the values. As for your other questions, I don't
| really know anything about audio.
| vadfa wrote:
| I like your blog a lot, thanks for existing.
| sennight wrote:
| Since you offered: what is that trace called that is presumably
| electrically connected to the ceramic cap solder seal? I've
| wondered about its function, but have never been able to
| distill the prior sentence to the necessary power words.
|
| Also, here is an extra ham-fisted attempt to get you to cover
| an off topic interest of mine: did you know that the
| Soundblaster DSP was an 8051? Cool, huh?
| pleasedoan8051deepdiveimbeggingyouplease. I'm aware of only one
| gate level analysis, with evidence of its existence on
| archive.org... tragically the spider never bothered with the
| actual zip file and the author is long gone.
|
| Thanks for all the great reads, btw.
| kens wrote:
| The gold trace connects the metal lid to pin 1 (ground). This
| provides some electrical shielding.
|
| As for the 8051, I might look at it at some point, but I've
| got lots of other projects...
| sennight wrote:
| ha, and here I'd assumed there was some convoluted vacuum
| getter / ion pump at the root of it... nope, just didn't
| wanna screw about with the bond wires. Thanks.
| [deleted]
| b20000 wrote:
| awesome work and right up my alley. look forward to digesting
| guerrilla wrote:
| That is some seriously clean routing.
| mortenjorck wrote:
| _> The underlying problem is that multiplication is much harder
| to perform with hardware than addition, especially with 1980s-era
| technology. The solution is that the chip uses base-2 logarithms
| in many places because adding logarithms is equivalent to
| multiplying the values._
|
| Maybe it would have been obvious to me if I had taken calculus,
| but this blew my mind.
| jacquesm wrote:
| Look at how multiplication is done with a sliderule.
|
| https://www.sliderules.org/react/aristo_0901_junior.html
| secondcoming wrote:
| Logarithms are taught before calculus where I grew up.
| shoo wrote:
| A similar trick is used for a different reason in statistical
| and probabilistic calculations -- for numerical stability
| rather than performance.
|
| Suppose you have n probabilities p_1, ..., p_n. Each p_i is a
| real number in the interval [0, 1] . Often you want to multiply
| probabilities to compute prod_i p_i . Probabilities p_i can be
| tiny floating point values (very close to zero) and if n, the
| number of factors, is large, then the product will evaluate to
| zero due to underflow.
|
| Software that processes probabilities often instead stores log-
| probabilities. Then the product prod_i p_i can be evaluated as
| sum_i log(p_i) , which is more numerically stable.
|
| Where this gets a bit trickier is if you instead want to
| compute the sum of probabilities, rather than their product --
| e.g. to renormalise probabilities so they all sum to 1. If you
| have encoded the probabilities as log-probabilities, you now
| need to take the log-exp-sum [1][2], which will cause numeric
| overflow if done naively, and is also relatively expensive to
| compute, as it requires n exponentials and 1 log to combine n
| log-probs. log-exp-sum can be evaluated in a stable way by
| first doing a pass over the data to compute the max log-prob,
| then doing a second pass to take the exponential of each log-
| prob offsetted by the max log-prob, so each of the terms being
| exponentiated is at most 0.
|
| There's also a streaming version of log-exp-sum that permits a
| single pass over the data [3] -- a max is calculated on the fly
| and each time a new max is identified, the running sum is
| multiplied by a correction factor. I'm a bit suspicious that
| the branches in the streaming log-exp-sum might cause a
| performance impact when executing, although each exp
| calculation is so expensive that perhaps it doesn't make that
| much of a difference.
|
| [1] https://en.wikipedia.org/wiki/LogSumExp
|
| [2] https://blog.smola.org/post/987977550/log-probabilities-
| semi...
|
| [3] http://www.nowozin.net/sebastian/blog/streaming-log-sum-
| exp-...
| nwallin wrote:
| > I'm a bit suspicious that the branches in the streaming
| log-exp-sum might cause a performance impact when executing,
|
| Since you're just checking whether the current sample is
| larger than the largest sample seen so far, you're very
| likely to find a "large" sample early that rarely gets
| updated. From then on, this branch will virtually always be
| false, and the branch predictor will make this fast. Unless
| the distribution is increasing (but not monotonically
| increasing) over time in an unpredictable way; in that case,
| the branch predictor will fail often and will be slow.
|
| The branch predictor (and cache, for that matter) is a sort
| of Schrodinger's cat that makes programs both slow and fast
| at the same time, but you never know which until you
| benchmark it.
| shoo wrote:
| > you're very likely to find a "large" sample early that
| rarely gets updated. From then on, this branch will
| virtually always be false
|
| Good point, provided there's a decent number of elements
| being reduced.
|
| In the application I've been focusing on, many of the
| batched log-exp-sum reductions are over tiny arrays
| containing 1 to 4 log-prob elements. There's already
| branching to guard against the case where all elements are
| log-prob -inf (aka probability zero). I found it helpful to
| also branch to special case the 1 element case, in which
| case the reduction is the identity operation, saving both
| an exp and a log. It's probably the case that inside the
| exp and log there's branching as well, so doesn't make
| sense to get too myopically focused on that single aspect
| of performance.
| aaaaaaaaaaab wrote:
| Calculus? Really? Logarithms are basic highschool math in my
| country...
| NullPrefix wrote:
| Such a shame that grammar wasn't a basic thing back there.
| jacquesm wrote:
| Or tact.
| mwfunk wrote:
| Fun fact: in the UK they call it marhs!
| dang wrote:
| Please don't put other users down, regardless of how math is
| taught in your country. We want curious conversation in which
| people treat each other well, even if they know less than you
| do. We do not want point-scoring and putdowns.
|
| https://news.ycombinator.com/newsguidelines.html
|
| Edit: you've unfortunately been posting unsubstantive
| comments and breaking the site guidelines with this account
| elsewhere, too. Can you please stop that so we don't have to
| ban you again?
| presspot wrote:
| We don't learn mahr here
| fnord77 wrote:
| It is a shame companies do not donate the actual design documents
| to a museum of some sort, like the Computer History Museum.
|
| Of course things get lost over the years. I wonder if companies
| could put their designs in escrow to be released after some
| number of years so they don't get lost.
| kennywinker wrote:
| This is basically the original logic behind patents. You trade
| making your invention public for legal protection of your
| exclusive right to that invention for some number of years.
|
| It's too bad it doesn't work anymore (or maybe it never
| worked?). Stuff like this doesn't make it into useful patent
| documentation, while patents are issued for vague and overly
| broad "inventions" like "storing numbers in a computer".
| kens wrote:
| The DX7 patent is actually pretty good:
| https://patents.google.com/patent/US4554857A
|
| It accurately describes the architecture of the DX7 and how
| it's implemented. There's a whole lot that it doesn't
| explain, but it was very helpful for understanding the chip.
| (I used a couple of diagrams from the patent in my article.)
| varispeed wrote:
| I don't know why patents even exist at this point. I have
| seen many times an obvious thing has been patented, where
| anyone sane wouldn't think of patenting something like that.
| Most likely this is to get a PR e.g. "we are using patented
| technology", but if you worked on a software and then you
| learn someone has patented something that your software does
| years later, makes you feel uneasy and there is no defence
| against that. One thing if companies are doing that for PR,
| but if "their IP" gets taken over by patent trolls...
| TheOtherHobbes wrote:
| >a PM signal will have little frequency change if the modulation
| is slow
|
| This was one of the programming tricks on the DX7. If you set the
| final carrier to a low frequency you got a nice drifty chorus-
| like effect.
| spudwaffle wrote:
| It's time to go to DX Heaven https://youtu.be/X9L60BUux1k
| lovelyviking wrote:
| Yamaha DX7 - Famous Sounds Demo:
|
| https://www.youtube.com/watch?v=BCwn26FePAo
| jacquesm wrote:
| Next level wizardry this, the speed with which this all came
| together is incredibly impressive, it took about as long to mail
| the chip as it took for Ken to do all this work.
| 5faulker wrote:
| This is cool shit. Hacker-approved.
| exhilaration wrote:
| Additional reading and discussion on the DX7 from 3 weeks ago:
| https://news.ycombinator.com/item?id=28940860
| kens wrote:
| Not a coincidence :-) I'm working with the author and the
| submitter of that article.
| mcraiha wrote:
| The Play example generates horrible sound if you press play and
| drag the Modulation frequency ratio slider. Using Chrome
| 95.0.4638.69
| kennywinker wrote:
| In Firefox I only hear a single sine wave of varying
| amplitude/frequency, not a modulated one.
| rotexo wrote:
| Reading this really drove home to me just how amusing some of the
| twists and turns of music tech development are. In contemporary
| modular synth formats, you now have modules that use similar FM
| tone chips, but are controlled by potentiometers and analog
| control voltage inputs (for instance,
| https://busycircuits.com/alm011/). I could see how someone could
| conclude that this destroys the reproducibility advantages of
| digital FM synthesis, while preserving the cheesiness of FM
| sounds. From another perspective, you can freely explore the
| enormous landscape of sound produced by FM synthesis, without
| diving into the deep end of DX7 programming. Instead of
| generating sysex dumps on the fly to dynamically change the
| sounds produced by the synth, you just feed whatever control
| voltage you can come up with into the inputs of a module and bask
| in the insanity that comes out (for instance--
| https://www.youtube.com/watch?v=2-YEbg040ww definitely not
| everyone's cup of tea).
|
| Edit: but if you want to explore the landscape of FM tones
| generated by these chips without spending all of your money on a
| modular setup, generating sysex messages will of course take you
| where you want to go: https://fo.am/activities/midimutant/
| djmips wrote:
| What do you mean? That's awesome!
| rotexo wrote:
| Oh I definitely think it is too! I could see other people
| dismissing the modular stuff as a waste of money, or the
| midimutant thing as a- or un-musical. Maybe I could have
| reframed this as a meditation on how quirky technology
| development can be when it is subservient to human creative
| urges. (Edit: spell check)
| klodolph wrote:
| "Basking in the insanity" just about sums it up. It's
| remarkably difficult to craft a good sound with FM synthesis
| (or phase modulation, for the pedants).
|
| My experience with FM sound design tells me that 2 operators is
| quite primitive, 3 operators opens up a larger set of non-
| insane possibilities, and 6 operators (like the DX 7) is,
| surprisingly, the minimum I would personally want to use for FM
| synthesis!
|
| So if you are going to go 100% FM, and you're going the
| eurorack route, I'd personally want nothing short of two
| ALM011s. You obviously don't need two if you're mixing it with
| other modules, it's just that if you want to do FM synthesis,
| four operators is surprisingly limiting.
| rotexo wrote:
| Oh for sure. An additional advantage of the modular approach
| is: if you don't like the raw FM tone, you can try running it
| through an MS-20 filter, or a Moog filter, or a wavefolder,
| or a ring modulator, or...
|
| One of my favorite custom SuperCollider synths that I wrote
| was a simple 2-op phase modulation generator run through a
| wavefolder and filter. I probably could have arrived at a
| similar sound with more operators, but it wouldn't have felt
| as intuitive to write!
|
| Edit: these darn mobile keyboards
| TheOtherHobbes wrote:
| FM was always possible with analog, but it sounded like a mess
| because you need digital stability to make consistent sounds.
| Tiny frequency variations that add drift to analog sounds and
| make them interesting will completely destroy an analog FM
| patch and turn into unplayable noise.
|
| If you really want to explore FM you can write your own code
| and create algorithms with as many carriers/oscillators as you
| like. This turns out to be less interesting than it might be,
| although if you use a lot of carrier/modulator pairs you get a
| kind of spicy variation on additive.
|
| It gets much more interesting when you add formants and other
| variations like the later FS1R synth did.
|
| If you want to keep the modular approach the various digital
| modulars - Reaktor, VCV Rack, Voltage Modular, etc - give you
| clean FM with patch cords.
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