Analog Circuit Modeling

[YISH313z]

Is this possible with the SDK?
What about with modular?

[astroman]

sure it is - according to Creamware's press releases Minimax was in large parts circuit-modelled
but it's a demanding task to evaluate those 'rules' by probing
(which is generally all you have to build a realistic model... analog sound is about irregularities)

cheers, Tom

[YISH313z]

what about using analog hardware schematics to build emulations, I do have a vst plugin(Salt) that uses schematics that you string together capacitors resistors etc to emulate a piece of analog gear, not sure how close to the hardware it comes as I dont have hardware to compare to lol, but it is interesting.

Another program LiveSpice has yet been put into VST but allows you to use Spice netlist to add components and string the schematics the same way as salt/spice and hear the results in realtime(cpu hog though). wishing for something similar in Scope to this degree, seems fun so far.

I do have one other VST from phi-L Audio, that is a Tube Preamp emulation based on resistors tubes and capacitors all adjustable, it sounds pretty cool for native, but somehow I believe if this framework were offered in DSP it would be more efficient and could sound more authentic. a sort of analog modular for creating hardware emulations.

I'm a dreamer I know

[djmicron]

on scope you have almost 1:1 emulation of real circuits, but you don't have 1:1 emulation of electronic components.
Working with the scope modular, you learn how to work with real modular synthesizers even without putting your hands on the real one.
In my opinion, for audio circuits prototyping, scope is great and there's no need to draw electronic circuit schematics to understand how a real world circuit would be, because once you understand how a synthesizer is built, it's a repetitive task to assemble the circuit parts and you can find the DIY stuff very easily.
Inside scope sdk, you have access to low level modules, of course you don't have a 10K resistor, but you have math modules, attenuators, etc.
What i mean is that once you know how a filter is made, you don't need each time to redraw the schematics to understand how it works, the same for vca and so on, but if for some reason you need to prototype with real schematics, then the already existing SPICE software is fine and as in the real world, the oscilloscope is your friend more that the audio speakers.

[YISH313z]

thanks. as far as synths goes, i think modular covers that whole gamut, was looking to emulate more on the effects side, preamps and stuff of that nature, alas as i do not have an SDK license nor a 15 dsp pro card to even request one its still a pipe dream at this point.

[Sounddesigner]

was looking to emulate more on the effects side, preamps and stuff of that nature,

When it comes to effects you may wanna contact Ray who runs dNa wich is a newer SCOPE developer company. He has a ear for analog and his plugins are a step above anything I've heard in Native world (and I am a huge fan of some Native plugins such as the latest T-RackS plugins, SSL Duende, etc). I don't know what dNa's modeling technique is but I do know there is some magic captured in his plugins (Method for developing is irrelavent to me anyhow, I'm more concerned with the sound of it as a Engineer). IMV dNa has figured something out, their plugins have a beautiful analog coloration but aren't too heavy-handed in that they blot-out/degrade-too-much the original source in a pluginish type of way. They still retain some of that SCOPE fidelity with the Analog coloring. Check out the dNa MasterComp and Stereo-equalizer - http://sonic-core.net/joomla.soniccore/ ... 36&lang=us

I fear many SCOPERS may be sleeping on dNa's SCOPE pkugins wich truly are impressive and a well needed addition to this SCOPE Platform. DNA is doing things in a high-level way no doubt.

As for your endeavors: It's always best you have a expert you can question (and hope they'll give up some of their secrets). And dNa uses the SCOPE SDK. You can contact dNa here as well as read more about them - http://dnamusic.nl/dNa.Scope/

EDITED

[djmicron]

thanks. as far as synths goes, i think modular covers that whole gamut, was looking to emulate more on the effects side, preamps and stuff of that nature, alas as i do not have an SDK license nor a 15 dsp pro card to even request one its still a pipe dream at this point.

if you look deeper inside the modular stuff, for example the bcmodular, there are sdk modules adapted to be used inside the scope modular, talking about effects, you can start with shapers, ring modulation, all pass filters, basic delay modules, etc.

[YISH313z]

Besides the ECC for tube emulation , what would I use to emulate Resistors, Capacitors and Transformers. I'm a complete noon at EE, but have a knack for creating things and taking the time to learn

[astroman]

transformers are a good example ...
there does not even exist a (standard) mathematical model to describe an arbitrary transformer in detail
(so virtual results equal the real world ones)

even audio experts like Waves only recently published emulations of some Neve stuff which claim to have covered the transformers in detail
(I have no idea if that's true or not)
transformers are very special devices - a wild mixture of (multiple) inductor, resistor, capacitor
the metal material matters, it's form, the way it's cut and arranged, slice dimension, isolation
same applies to the wire: material, size, isolation laquer, pattern of winding it to the core

that's why convolution is so much appreciated - send a signal, store the response
(not much thinking required)
while it will capture some similiarity, it hardly will get the full dynamic spectrum of (possible) interaction
(attempts with more sophisticated probing signals like the Kemper Profiling Amp for guitar seem to work quite well)

cheers, Tom

[djmicron]

Besides the ECC for tube emulation , what would I use to emulate Resistors, Capacitors and Transformers. I'm a complete noon at EE, but have a knack for creating things and taking the time to learn

Resistors can be emulated using attenuators, capacitors can be emulated using filters and delay lines, transformers can be emulated using shapers.

Using scope, it's better to look at ready to use circuit snippets, than looking at single components.

Watching at the waveforms is an essential task to better understand what a signal processor does, for example try with simple sine waves and watch at the oscilloscope to see what happens after the processing, this can be useful to emulate real hardware processors, also it can be useful to analyse the frequency spectrum, this can be done using pink noise.

[YISH313z]

Thanks, I will give it a shot with these suggestions.

[jhulk]

the vca is the most common part used in electronic circuits

by using the vca as a building block you can make waveshapers complex oscillators and filters

with the use of comparators diodes

a capacitor is a charge and release device in an oscillator a transistor charges a capacitor which rises at a timed amount when it reaches its full capacity it is short circuited and the full charge is released it then filll up again with voltage charge this is known as a ramp wave or saw wave if you invert it you get a down saw wave the faster it is charged the faster the waveform and so with the help of circuits to change the timing of the charge you can vary the speed or tuning of the waveform

a square wave is created either by a ramp wave or a tri wave a comparator is used with a threshold you take an non inverted input to one side and a inverted input to the other the threshold is set and when it reaches it it switches to the other input which is inverted creating a jumped stepped wave by modulating the threshold you get the comparator to switch quicker or slower this creates a pwm wave

by using a ramp or tri you actaully get different types of square waves and why different types of asic osc chips sound different cem ssm or discreete i.e minimoog which uses a npn pnp matched pair the good thing about dsp is that you dont have to account for temp drift which is necessary in analog electronics and why matched pairs and a thermocouple resistor is used to keep the circuit at a constant temp so that tracking can be performed correctly

waveshapers are the other things used diodes in dsp we have halfwave rectifiers and fullwave rectifiers which is what a diode function does makes a ac wave into a dc wave with ripple or used for short circuits with no reverse voltage this allows the circuit only to flow one way and so the short circuit does not cause a short circuit as it is controlled by the diode the diode can be used as a clipping circuit in a tri wave to create a sin wave by clipping the peaks of so that they are flattened then a 1 pole 6db filter is used as a slew which rounds of the flattened peak and makes it rounded.

with the use of lfo and vca and a multi output oscillator you can create a complex oscillator this is accomplished by taking the oscillator output like the bcmulti osc which has 3 outputs and if you invert each one aswell you have 6 outputs by taking them to 6 vca and using 3 lfo which outputs are inverted also then taking there outputs to a bipolar module which only does 0 to max 32bit number just on off

and setting different times on the lfo and then taking there outputs to a summing mixer with volume control the output from the summing mixer will be a complex oscillator waveform by changing the levels of the summing mixer inputs you change the shape of the oscillator this can all be done in real time one hardware module like this is the living vco

you can also do screw of waveforms this is done by using 2 osc waveform outputs and using a crossfade mixer when you crossfade you mix the waveform from one to the other which is one half of vector mixing which does the same thing complex sounds can be created via mixing sounds additively this way its also a common way to create a pwm wave from any waveshape by inverting one waveform and then crossfade mixing them you create a modulated waveform that cancels its self out creating new spectra as frequencies are removed

you can do the same with filter inputs to create complex filter outputs 1 common one is the sem voice synth this has its lowpass filter and hipass filter go to a crossfade mixer which creates a notch output in the center as each filter cancels the other out leaving only frequencies that neither has giving a reverse peak.

all things can be emulated with the building blocks in scope modular and bcmodular and flexor there are so many building blocks that complex modules you buy are made up of the same thing mostly a core module osc/filter and then vca as waveshapers and volume attenuators to give them complex functions the memorymoog uses 36 dual vca chips for its 6 voice synth they are mostly used for modulation as the synth its self uses just 6 vca per voice board thats just 3 cem3360 chips 2 chips are used for the mixer and 1 chip is used for the vca and the resonance feedback from the transistor ladder so 18 cem3360 are used for modulation thats 36 vca just for complex modulation duties

formant filters are banks of bandpass filters set to certain frequency and resonant settings then vca for the level of the peak of the formant frequency just from several bands complex shapes and filter contours can be created

same as filter banks which are filters set at eq frequencies and use a vca just for the level of the filter

ringmodulator which uses the summ and difference of the 2 input waveforms or a vca which control input uses a audio source to put its contour onto a incoming audio signal to the vca input am modulation

phase modulation fm as used in the dx7 series you can use a single op as a sin waveshaper by using a constant waveshape input as modulator you can then change the sin into a complex shape you can do this with a sample osc with a frequency slider to the frequency input making a sin waveshaper oscillator

phasers which are cascaded allpass filters

flangers you can create with small delay modulators and an lfo and the mix back of the original signal which causes phase cancillations

all the building blocks are there and with the use of the clm module you can create custom modules to reuse time and time again as new mdls

[YISH313z]

Wow. I'm going to have to soak this in. Very informative.

Thanks!

[astroman]

yes - that's the way it's modelled...
just keep in mind that not a single one of those methods correctly replicates an analog circuit
most simple example:
the resistor - it also introduces noise, less if made from metalfilm, more if made of pressed carbon
in a capacitor the isolation material can have a significant influence
(if you look at analog delays with bbd chips you'll always find a polystyrol type at a certain position)
etc...

cheers, Tom

[jhulk]

if you still have pci cards then have a dual system 64bit on the xite and 32bit on the pci then you have best of both worlds

then just link them via adat i do that on my machines and you can then use the 32bit samplers and the sts bcmodular sample osc which you can create some neat sample instruments

or hybrids with fm and virtual and sample playback

a great way of doing your own vector mixer and the way i prefer doing it is have a 4 layer synth per one voice but each layer hads its own filter and vca and set of 3 envelopes pitch/filter/vca

then i take there outputs and take them to a mix 1 module

i then take a constant control module and set it to max 32bit number and take its output to a panning modules i then take the left and right outputs to layer 1 + 2 now when a modulation input is modulated it will change the mix one modules volume

by adding 2 of these you now have layer 1+2 and 3+4 and you can use a joystic module which has a x/y outputs which you can add to the 2 panning circuits control input or you can set lfo or envelopes or using a modulation mixer a sum of all controls

now once you have created this vector transient mixing module if you create it in a bcmodular clm shell you can then save it as a module for reuse in any device you create

this is how i build up my utility modules i follow circuits as there building blocks and how they flow from one module into another and i follow the modulation matrix and set up a modulation matrix but what it boils down mostly is the sound what your aiming for is the emulation of the sound and the best way of doing that is fft analysis and noise so you can see the spectrum used

and also the waveshape in oscillators there are many waveshapes as each manufacturer uses its technique in designing the circuit which adds harmonic differences

if you want the noise from an analog synth then you sample it just with the synth switched on this will give you the background noise then just add it via a vca at the end of the chain

this is what the dcam synth squad plugins use they call it analog noise

if anyone wants several analog noise samples from analog synths i can arrange that as im always repairing them this week end i will be working on a jupiter4 and a yamaha cs10 and a clear pentephonic

[jhulk]

also its good to draw a flow chart of the circuit you want on paper first i always do this as it gives me a visual idea

when i built a quadratic lfo in bcmodular i used 4 multilfo in a clm shell

each lfo was set to a phase and then an inverter module was used for the opposite phase

this gives you 8 lfo outputs at different phases

all frequency inputs are controlled from one frequency control so all work at the same frequency

i added 4 level controls for each lfo i wire it up so all outputs and inputs come from the outside world of the clm shell this allows you to have a complex circuit inside the clm shell

but easy controls on the outside and now with scopesync you can add the controls to a vsti panel which makes life easy as you can just make loads of clm shells as utility blocks and wire it up from the scope sync panel this saves on space in modular and time of adding each separate control module as before

quadratic lfo are great for modulation fx as you can use them with phasers and ringmodulators for pitch shifting

[yayajohn]

was looking to emulate more on the effects side, preamps and stuff of that nature,

I fear many SCOPERS may be sleeping on dNa's SCOPE pkugins wich truly are impressive and a well needed addition to this SCOPE Platform. DNA is doing things in a high-level way no doubt.

+1 on DNA! Great plugs and very reasonably priced. Haven't heard from Ray in a while.....i'm sure he's hard at work on his next set of awesomeness.

[Sounddesigner]

was looking to emulate more on the effects side, preamps and stuff of that nature,

I fear many SCOPERS may be sleeping on dNa's SCOPE pkugins wich truly are impressive and a well needed addition to this SCOPE Platform. DNA is doing things in a high-level way no doubt.

+1 on DNA! Great plugs and very reasonably priced. Haven't heard from Ray in a while.....i'm sure he's hard at work on his next set of awesomeness.

I see dNa are 'right on que'. Soon as we speak about them they release some new plugins - http://www.sonic-core.net/newsletter/20 ... iling.html

It's great to see the SCOPE Platform start out the new year with new products for the platform. dNa always has my eye and anticipation, love what I bought from them so far. They are top-notch and the real deal.

[yayajohn]

nice timing! yeah!