# Is the "analog synth" sound created by slight fluctuations in voltage within the synth?



## ManicMiner (Jan 4, 2019)

As I understand it, the unique analog sound of the hardware synths of the 80s is due to the fact that the voltage was not always constant, and this instability caused the waveforms to exhibit slight imperfections.

Is that about right ?


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## givemenoughrope (Jan 4, 2019)

I thought it had to do with them warming up and going slightly out of tune. Modern analog synths with DCO’s sound slightly imperfect compared to software also though.


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## ed buller (Jan 6, 2019)

yes...simply put. Synthesizers where first Voltage Controlled . This allowed two areas of chaos to flourish. The first would be at the power supply. Power would come in from a wall socket and be stepped down to a small enough voltage to be useful. First difficulty , fluctuations at this point effects the whole synth !


Next the system requires 1 volt per Octave. Now Pitch is not Linear. It's exponential so we need to convert the voltage to climb exponentially . Second area of chaos . This " Exponential Generator " is not going to behave properly at all. It will track all over the place. So in the first Octave the fifth might be a bit flat and the seventh a bit sharp, In the second the third might be sharp and the sixth flat....etc. Plus each oscillator needs them !......so on a big system ALL the oscillators are tracking at slightly different pitches. Now this is actually VERY musical . If you've ever had to make an album with lot's of Mulitrack guitar parts you'll know how hellish tuning can be . On top of this the voltage supplying the oscillators isn't constant....it will have a tiny ( if you're lucky ) wobble. Sometimes very fast, perhaps 10 hz. If I plug in my oscillators on My Moog system they sound like tiny mosquitoes . This too adds to the chaos. Factor in clipping and rectifying throughout the system and it all turns into a glorious fat warm synthi mush .


To people my age THAT is what a synthesizer sounds like !

best

ed


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## sostenuto (Jan 6, 2019)

ed buller said:


> yes...simply put. Synthesizers where first Voltage Controlled . This allowed two areas of chaos to flourish. The first would be at the power supply. Power would come in from a wall socket and be stepped down to a small enough voltage to be useful. First difficulty , fluctuations at this point effects the whole synth !
> 
> 
> Next the system requires 1 volt per Octave. Now Pitch is not Linear. It's exponential so we need to convert the voltage to climb exponentially . Second area of chaos . This " Exponential Generator " is not going to behave properly at all. It will track all over the place. So in the first Octave the fifth might be a bit flat and the seventh a bit sharp, In the second the third might be sharp and the sixth flat....etc. Plus each oscillator needs them !......so on a big system ALL the oscillators are tracking at slightly different pitches. Now this is actually VERY musical . If you've ever had to make an album with lot's of Mulitrack guitar parts you'll know how hellish tuning can be . On top of this the voltage supplying the oscillators isn't constant....it will have a tiny ( if you're lucky ) wobble. Sometimes very fast, perhaps 10 hz. If I plug in my oscillators on My Moog system they sound like tiny mosquitoes . This too adds to the chaos. Factor in clipping and rectifying throughout the system and it all turns into a glorious fat warm synthi mush .
> ...



Maybe a 'fun' question for Arturia & other sources ….. they are surely aware of this and wonder if they have tried to include some of this chaos in their VI products. 

Even Keyscape must be too 'sterile', as line voltage now is much cleaner and more stable.


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## ed buller (Jan 6, 2019)

yes part of the physical modeling that goes in in their designs is to mimic this

best

e


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## chimuelo (Jan 6, 2019)

Save yourself money and buy Native synths for recording but if your performing live prepare for real drums bass and guitar to bury your PC regardless of the volume.

I’ve been using Native for recording over the years and in the last few years all of the performance features that were difficult to achieve like separate oscillator glide, filter tracking and oscillator stacking without phasing is damn good.

But live if your just playing samples and are doing smooth jazz, maybe a horn or two it’s fine, but for dance or especially rock you have to have discrete audio punch. 

I wish it weren’t the case, and Ive tried, but Studio Electronics SE-1Xs SE-02s and Code 8s in a live venue is the only way Ive kept Guitarists from making my synths sound like Kazoos. Same goes for software Hammond B3 clones. I’ll use hardware for that too.

Thank God our samples in many cases sound as good.

I’m looking forward to the Native synths doing the same but unfortunately for me it’s still not there.

Funny how my Native synths bury my sampled guitars though in recordings.
It’s their only time for revenge.


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## ManicMiner (Jan 7, 2019)

ed buller said:


> yes...simply put. Synthesizers where first Voltage Controlled . This allowed two areas of chaos to flourish. The first would be at the power supply. Power would come in from a wall socket and be stepped down to a small enough voltage to be useful. First difficulty , fluctuations at this point effects the whole synth !
> Next the system requires 1 volt per Octave. ...
> best
> ed


thanks, thats helpful


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## charlieclouser (Jan 7, 2019)

Thinking about "analog-ness" in a wider scope, like why large-format analog mixing consoles sound different to numerically-perfect DAW summing or whatever, then you start to consider not just voltage fluctuations, as you'd consider in an analog synth voice, but manufacturing tolerances on a wider scale. The tolerance of resistors, capacitors, even the traces on circuit boards - all of those aspects are never spot-on, but have some wiggle room. 

Sure, there's "mil-spec" components which are rejected if their measured values fall outside of a narrower range than components deemed acceptable for consumer use, but go further down the rabbit hole and you start to wonder how much of an affect on the sound you will get if the thickness of the traces on a circuit board vary a little bit from board to board, or even from one area of the board to the next. Think of all the miles of printed board traces, interconnect wiring, ribbon cables, and tens of thousands of individual resistors, capacitors, etc. inside a 64-channel SSL analog console - it's a miracle the thing doesn't output pure radio static! So it's not surprising that all of those things, acting together, will create some "smush" factor in the signal, where what comes out isn't exactly what went in (or was expected). But over long years of trial and error the designers find which components are most crucial, and which components, even when behaving imprecisely, provide "euphonic" results. The experience and design strategies of a zillion designers and fabricators have been intermingling for decades now, and the combined result of all of that experience took us to the pinnacle of analog circuit design which I think was around the late 1990's / early 2000's - just as the DSP revolution started sawing the legs off of the analog chair.

Since then, sure, we've seen continued advances in analog design, but it seems more aimed at lowering the cost of precision manufacturing in order to remain competitive with digital solutions, except for boutique stuff like Fairchild clones and stuff like that. 

Anyway, all of those zillions of components, operating at plus or minus XX percent of their stated values, combine to create "the analog sound", and it's more than just unstable voltages at the power supply or VCO core. Think of an OB-Xa synth with eight voice boards - each of the eight boards was intended to be identical, but due to these variations in every aspect of analog components, could never be. But whether it was the capacitors in the filter circuit of voices 1,3,4, and 8 behaving differently than those in voices 2,5, 7, and 8, or all 16 of the VCO circuits tracking ever-so-slightly differently... all that stuff taken as a whole is, I think, at the heart of "analog goodness". 

Even with modern, precise manufacturing techniques, it only takes five seconds to hear that a Prophet-6 or OB-6 has "that thing" that even a "half-analog" synth from the same manufacturer like the Prophet-12, doesn't have... or doesn't have as much of anyway. When they add in features like "slop mode" and such, that certainly does help simulate the messiness of older, crusty, charmingly-out-of-whack synths that may have sat in the garage or pawn shop for too long, but even without those features, a pure analog design will always have some of that lovable gooey mess that a simulation won't - unless special measures are taken.

Now, this isn't news to plugin or VI designers, and for sure they often try to simulate these variable tolerances, to varying degrees of success. One approach that I thought was interesting to see recently is Brainworx's idea of "TMT" or "Tolerance Modeling Technology", where a channel-strip plugin can, when instantiated across many channels, behave slightly differently for each instance. In their marketing materials they claim to have "modeled" each of the 64 channels of an actual analog console - whether that's precisely true, or whether they've just created an array of 64 value sets for those "tolerances" which can then be applied so that each instance sounds a tiny bit different to the next, I cannot say. But it is a great idea and seems to work - although it's pretty subtle and depending on your source material may not make much of a difference. 

But the idea is sound and it's a direction I'd expect to see appearing as a core feature in the DSP mix engines of our favorite DAWs any day (year?) now. Imagine if your Cubase or Logic mixer had a few knobs for things like "VCA leakage", "buss crosstalk", "resistor age / variance", etc.? That might help to loosen up the "too-tight, too-precise" sound of modern DAW summing that some people (not me) complain about. That's a whole rabbit-hole of potential marketing jargon that I'm surprised we haven't been thrown down already.

Get ready - controllable "faultiness" will be the next marketing buzzword! Might sound good though.


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## sostenuto (Jan 7, 2019)

charlieclouser said:


> Thinking about "analog-ness" in a wider scope, like why large-format analog mixing consoles sound different to numerically-perfect DAW summing or whatever, then you start to consider not just voltage fluctuations, as you'd consider in an analog synth voice, but manufacturing tolerances on a wider scale. The tolerance of resistors, capacitors, even the traces on circuit boards - all of those aspects are never spot-on, but have some wiggle room. *******************
> Even with modern, precise manufacturing techniques, it only takes five seconds to hear that a Prophet-6 or OB-6 has "that thing" that even a "half-analog" synth from the same manufacturer like the Prophet-12, doesn't have... or doesn't have as much of anyway. *****************
> 
> Now, this isn't news to plugin or VI designers, and for sure they often try to simulate these variable tolerances, to varying degrees of success. One approach that I thought was interesting to see recently is Brainworx's idea of "TMT" or "Tolerance Modeling Technology", where a channel-strip plugin can, when instantiated across many channels, behave slightly differently for each instance. *********
> ...



No surprise to see you cover this so thoroughly. 
Much of my time spent before, _and through_, golden aerospace age (mid-50s through late 80s). USAF, Aerojet-General, Hewlett Packard. Fortunate to experience the incredible transition from almost total analog to ~full digital. 

_One article recently really caught my attention …. talking of ?? major studio where top engineers preferred to do top talent work near midday …. when console transformers had reached stable, optimum temps. Of course of those component tolerances played their roles as well.
_
THX for your 'insider' perspectives !


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## charlieclouser (Jan 7, 2019)

sostenuto said:


> _One article recently really caught my attention …. talking of ?? major studio where top engineers preferred to do top talent work near midday …. when console transformers had reached stable, optimum temps. Of course of those component tolerances played their roles as well._



Okay, that's one I'd never heard before! But I guess it could make sense, although in the era I worked on big analog rigs everything was pretty stringently climate-controlled, and never powered-down, so we never really needed to account for warm-up time - except for the talent!

It's still amazing to me when I see the guts of a big SSL console, and think of all the man-hours that went into each individual component - never mind the system as a whole. It's mind-boggling, the cumulative expertise and experience that went into the gear we used in the "big iron" years. 

As to the reason why people seem to want / prefer the older, wobbly, imperfect sonic qualities of vintage synths - I think there's a simple answer to that: The synths are a musical instrument, and our entire shared cultural history of listening to and appreciating music originated with instruments which were acoustic (voice, drums, violins, etc.) or at least electro-acoustic (electric guitars, rhodes, wurlitzers, etc.) and all of those never play the same note twice in exactly the same way - two of the same notes will never phase-cancel out all the way to zero. So when we hear a "numerically perfect" simulation, whether it's a VI synth or a (non-round-robin) sample set, something in our brain detects the perfect-ness of the repetition and deems it "incorrect". I mean, we all learn that on day one of trying to augment or replace a snare sound in a live drum recording with that one awesome snare sample you're able to isolate off a Zeppelin record or whatever - that one awesome sample sounds like ass if it's just repeating on every two and four. As soon as we got huge sample sets with dozens of round-robins and velocity zones, that "incorrect-detection" circuit in our brains doesn't set off alarm bells - or, at least, not as often. 

But that's why the golden-age synths seemed to blend so much better with ordinary guitars, drums, and voices, like on a Talking Heads or Pink Floyd record: the synths had imperfections and "wiggle room" in the same dimension that the other sounds they were sharing space with did, so nothing sounded "off". It all just blended together in a smooth, euphonic manner. Lack of time quantization has a lot to do with that as well - human slop!

I think that mental detection circuit at work is part of the reason why the rise of Auto-Tuned vocals, even to the extreme pitch-quantized mode that's popular in modern music genres, is more acceptable: it's all down to context. So many of the other instruments that the vocal is sharing space with in a Katy Perry or Post Malone song with ARE "numerically perfect" and don't have that human-scale wobble to them, so a natural-sounding vocal all of a sudden feels "wrong" or like it's not in the same "place" as the track. But turn Auto-Tune up to 100% and all of a sudden the vocals are locked-down in a similar way that all the instruments are. Boom - the contexts match, our mental detection circuits don't detect a "context conflict", and it sounds right - or at least, not like a mis-match. If you put the laser-beam auto-tune on Roger Waters' vocals on The Wall it would sound like a crime against art and nature, because all of the other elements are so humanized - but when all the other elements are de-humanized, then it sounds wrong if you DON'T de-humanize the vocal. I mean, not entirely, but you get what I'm saying. So I can excuse some of the trends in modern production to "auto-tune all the things" because I recognize that "context conflict" stands out to even a casual listener as being "wrong" even more than the "wrong-ness" of auto-tuning something in the first place. If you took a modern trap-rappers auto-tuned vocals, and put them on top of a track that was a super-live, Amy Winehouse style groove, it would probably sound... not right - but on top of a precise, in-the-box (laptop) track, it somehow works.

Not that I like the sound of, or approve of, the auto-tune revolution - but I understand why it works in that context.


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## brenneisen (Jan 8, 2019)

charlieclouser said:


> Not that I like the sound of, or approve of, the auto-tune revolution



yes you do, sir! do not think we'll forget your auto-tuned (or was it pitch quantized?) theremin


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## charlieclouser (Jan 8, 2019)

brenneisen said:


> yes you do, sir! do not think we'll forget your auto-tuned (or was it pitch quantized?) theremin



Okay, that's a fair cop. Guilty as charged. But you know I'm referring to modern auto-tuned vocals, right?

Still, when it comes to analog smoosh-and-wobble-factor, I do prefer it in my analog synths, but strangely I actually prefer digital precision when it comes to questions of mix-bus "mojo". When mixing big, complex tracks that pushed the limits on big analog consoles I'd get to a point where things sounded fat and full, but I wasn't done yet - and as I added just a few (dozen) more bits and pieces the mix would start to go from standing tall and proud to... wilting a little under the load. I'm sure this was due to me not being a great and experienced mixer, or constantly going back to the sequencer (that was always running live during the mix) to add another layered snare sample or whatever... or maybe it was because I'd been up for two days on a bender trying to finish the damn thing... but I'd get to a point where the mix bus is bending just right, and all of a sudden it's bent too far and now I'm trying to figure out how to ever-so-slightly back off a zillion elements to get back into the sweet spot. Then it's like a paper clip that's been bent back and forth too many times and it's getting fragile at the joint. 

Admittedly, this only happened with gigantic mixes on the SSL 4k, and didn't really happen on my lowly (but beloved) Mackie 8-bus rigs - but once I switched over to mixing in the box, or even on my dual Yamaha 02r setup that I used for a few years, I didn't have the same kind of struggles. Since there was no spot that was really any sweeter than any other, I could trim a zillion elements by 3db each and the result sounded the same, only quieter - so if things got a little too hot I could back things off without wondering why it all of a sudden didn't hit so hard. I wasn't trying to hit just that right zone where the 4k mix bus was flexing but not breaking. Guys who mix on 4k all their lives seem to intuitively know how to stay in that zone, but I never got the hang of it. Probably because I was always doing the programming, all the computer-sequencer fiddling, and all that stuff as well, so my attention was divided. Guys like Alan Moulder and Dave Ogilvie never had a problem making the SSL sing!

But with scoring-type music, where there's such a smorgasbord of loud sounds being played softly and soft sounds being played loudly, it's so much easier for me to get a mix to sound the way I want without having to tap-dance around the threshold of the mix-bus-mojo. 

But I'll happily admit that when I first auditioned an OB-6 it was immediately apparent that the raw sound of the saw waves on the oscillators was hugely different to the "equivalent" waveforms coming out of a Prophet-12 or a Pro-2. Same manufacturer, same filters, but all of a sudden I heard more girth, more "spit", just more.... good. For that particular sound and purpose, of course. Not to say that I keep dozens of analog VCO polysynths lit up for everyday use, but... there is a difference. If it matters to someone for the kind of music they're making that day is a question only that someone can answer, and only on that day. But I recognize that it's there, and not easy (or even possible) to simulate. So I keep a few true analog monsters on deck for when that's needed.


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## brenneisen (Jan 8, 2019)

charlieclouser said:


> But you know I'm referring to modern auto-tuned vocals, right?



ov course, just being witty


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## lux (Jan 8, 2019)

charlieclouser said:


> I think that mental detection circuit at work is part of the reason why the rise of Auto-Tuned vocals, even to the extreme pitch-quantized mode that's popular in modern music genres, is more acceptable: it's all down to context. So many of the other instruments that the vocal is sharing space with in a Katy Perry or Post Malone song with ARE "numerically perfect" and don't have that human-scale wobble to them, so a natural-sounding vocal all of a sudden feels "wrong" or like it's not in the same "place" as the track. But turn Auto-Tune up to 100% and all of a sudden the vocals are locked-down in a similar way that all the instruments are. Boom - the contexts match, our mental detection circuits don't detect a "context conflict", and it sounds right - or at least, not like a mis-match. If you put the laser-beam auto-tune on Roger Waters' vocals on The Wall it would sound like a crime against art and nature, because all of the other elements are so humanized - but when all the other elements are de-humanized, then it sounds wrong if you DON'T de-humanize the vocal. I mean, not entirely, but you get what I'm saying. So I can excuse some of the trends in modern production to "auto-tune all the things" because I recognize that "context conflict" stands out to even a casual listener as being "wrong" even more than the "wrong-ness" of auto-tuning something in the first place. If you took a modern trap-rappers auto-tuned vocals, and put them on top of a track that was a super-live, Amy Winehouse style groove, it would probably sound... not right - but on top of a precise, in-the-box (laptop) track, it somehow works.
> 
> Not that I like the sound of, or approve of, the auto-tune revolution - but I understand why it works in that context.



This is so true. It applies to quantization as well. It kinda hurts that sometimes I enjoy classics from the 60-70-80-90's and I spot amazingly upfront time inconsistences, stuff played off-beat and such. And it's not just the Stones' style of recording, where you get that tambourine hits randomly all-over those amazing classics, it's also pretty audible in most songs before the digital era. It makes me feel bad as I know I'm detecting those just because my ears are overquantized. It's like a cultural disease.

I also feel that synths from the analog and early digital era sound different because of amplifiers and the output signal chain. Basically there were concepted to "have a voice", with less care of "flexibility" and "neutrality".


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## charlieclouser (Jan 8, 2019)

lux said:


> I also feel that synths from the analog and early digital era sound different because of amplifiers and the output signal chain. Basically there were concepted to "have a voice", with less care of "flexibility" and "neutrality".



Yup. Most evident in the MiniMoog Model D, where the control ranges are maybe not as wide as they could be (or were in other synths) but the result is that the whole thing is one big sweet spot. It's like it's impossible to make a "bad" sound. You can make lots of sounds that you might not like, or might not be right for a given piece of music - but almost none of them are "bad".


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