Connecting the KO II to external gear.

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Links:

+ TE website

+ KO 133 website

+ KO II 133 online manual

+ KO II online sample tool / editor

Eurorack & Analog 16' Clock

This is an analog trigger. It's equivalent PPQN is 4.( ie four pulses per quarter note
or 1⁄4 the duration of a quarter note.)
It's also called 16th because a note is sent or received every 16th note.

enter system settings by pressing (shift) and (erase).

use (minus) and (plus) to navigate to the sync settings, then press (enter) on the pads.

use (minus) and (plus) to navigate to ‘in’ or "out", then hit (enter). 

use (minus) and (plus) to navigate to ‘16’, then hit (enter)

The K.O.II will now listen for or send out  a 16 clock pulse on it’s sync-in/out jack, 

The output clock pulse is 3.3V

RING: Start/Stop

Sync input

max level: 10 V

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Pocket Operator, Korg SQ-1, Volcas (8' clock)

(POs sync on audio pulses... essentially a click track).

Korg SQ-1 sequencers and the Korg Volcas use this standard.
A single KORG pulse is equivalent to just 2 PPQN.

It's also called 8th because a note is sent or received every 8th note.

enter system settings by pressing (shift) and (erase).

use (minus) and (plus) to navigate to the sync settings, then press (enter) on the pads.

use (minus) and (plus) to navigate to ‘in’ or "out", then hit (enter). 

use (minus) and (plus) to navigate to ‘8’, then hit (enter)

The K.O.II will now listen for or send out  a 8 clock pulse on it’s sync-in/out jack, 

The output clock pulse is 3.3V

RING: Start/Stop

Sync input

max level: 10 V

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Roland Drum machines (Sync 24)

In the case of MIDI (and Roland DIN Sync), the standard is 24PPQN.
Lots of old Roland Synths such as the TB303 & TR606, 808, 909 use this standard.
Most DAWs will also use  a 24 PPQN signal

enter system settings by pressing (shift) and (erase).

use (minus) and (plus) to navigate to the sync settings, then press (enter) on the pads.

use (minus) and (plus) to navigate to ‘in’ or "out", then hit (enter). 

use (minus) and (plus) to navigate to ‘24’, then hit (enter)

The K.O.II will now listen for or send out  a sync24 clock pulse on it’s sync-in jack, 

---------------

MIDI (in)

Teenage E use TRS MIDI type A connectors These transmit MIDI over standard Stereo cables

+ Midi/DIN  to TRS 3.5mm

control K.O.II with a midi keyboard

once you have your midi keyboard connected, K.O.II will detect any notes and light up the MIDI or usb icon (depending on what input is used) on the screen.

Each note of the keyboard will play a different pad

If you want to play one pad transposed across the keyboard just press (keys)!!

MIDI (out)

To control external synths with the KO II

Go into EDIT

(Shift + Sound)

Press the +/- key till you arrive at MID

Each pad sends MIDI on its own channel.

Select a pad and Use the orange knobto change the midi channel.

Midi clock using the Kenton Solo Eurorack module

 Some settings of a very useful Eurorack module. ... the Kenton Solo

 

I think this is ideal for use with a Modular - 

eurorack

 

Preset 70 has too fast a clock.

Use P.71 instead 

available values c24, c48 & d2 to d24,
- sets the ratio of MIDI clocks to output pulses from the Clock1 output.

 

 D12 seems about perfect.

If set to d2, there will 12 pulses from the clock1 output 

for every 24 MIDI clocks = 12 cpqn
If set to d24, there will be 1 pulse from the clock pulse output for every 24 MIDI clocks = 1 cpqn
(Note there are 24 MIDI clocks per quarter note)

 

So d12 = 2 pulses from the clock output for every 24 MIDI clocks

Comdyna GP-6 - introduction to the patch bay

The Comdyna GP-6 is an old analog computer from 1968.

It's great for solving differential equations.

This particular machine is being repaired. When it's running I'll do some demos

hopefully with some synths.

I've ordered a THAT computer which I'll compare with this.

This post is mainly a exploration of analog computer components 

but using the GP-6 as an example.

They all look pretty intimidating at first.

but the components belonging to most analog computers are fairly common...

Potentiometers, comparators, integrators, inverters, summers, multipliers, etc.

Many of these circuits use op-amps.

According to the Comdyna site, "Each GP-6 is a self-contained unit capable of simulating linear and non-linear systems of up to four state variables. Over 2000 GP-6 analog computers have been installed in over 400 university, government and commercial research laboratories."

 

Of course there is no keyboard or memory.

All programming is done with banana patch cables.

 

Virtually all analog computers have 3 basic elements:

1. Potentiometers (coefficient potentiometer).

2. Inverter / Summers

3. Integrators

 

 

-----------------------------------------------------------------------------------------

 

Below are  the COEFFICIENT POTENTIOMETERS . . . 

There are 8 of them.

Its the best place to start .... its how you input data.

These are ten turn pots, which  are used to input values (or coefficients) of the problem to calculate.  

The 8 coefficient potentiometer knobs dial in analog voltages.

 

Settings are displayed by the digital voltmeter in the POT SET mode.....

The coefficient potentiometer (pot) is a variable resistor (in effect a voltage divider ). 

It outputs a voltage which is some fraction of the input voltage. 

The output (the wiper arm) is usually connected to the input of one of the computing components  

 

The left two pots: Y/POT ADDRESS & X ADDRESS

These two rotary switches enable amplifier outputs and potentiometer wipers to be selected for digital voltmeter readout or output to an X-Y monitor such as an X-Y oscilloscope or X-Y plotter.

 

The MODE SELECTOR switch is positioned to POT SET for potentiometer setting and other check-out operations. Otherwise the switch is set to OPR.

 

POWER & COMPUTE TIME

(extreme right pot)

In addition to power on/off the COMPUTE TIME switch serves also to adjust the compute time or integrate period in a range of 10 to 100 scaled seconds. The time base ramp may be selected the X ADDRESS switch, TIME position, to be the XY plotter or oscilloscope horizontal axis.

 

On the patch panel the Pots connect to these central yellow bananas. Numbered 1-8

 

 Notice that 6 of these are connected to ground. (1-6)

These only have two connections.

Notice that Pots 7 & 8 have 3 connections.

The lower jack is free floating.

So you can connect a different voltage (other than ground)

to the lower jack.

So the output can even be a -ve voltage

 

--------------------------------------------------------------

In total there are 8 op-amps.

 

These make up the Inverters / Summers & Integrators

 

Integrators 

There are 4 integrating amplifiers on the top of the patch bay.

They are numbered 1,2.3.4. 

Integration is probably the most important operation available on the analog computer.

 

What is an integrator?

It's an element whose output signal is the time integral of its input signal. 

In other words tt accumulates the input quantity over a defined time to produce a representative output. 

The op amp produces the integral conversion of the initial input voltage.

Integration is time dependent.

The important bit to remember is that the negative feedback loop uses a capacitor. 

Intergators can be found in the modular synth world.

I understand that the Make Noise Maths and the Serge slope generators uses integrators

as well as in some state variable, LP & BP  filters eg Polivoks and WASP .

https://www.youtube.com/watch?v=esKrrjFJyuk

Summers

There are also 2 summing amplifiers in the centre of the patch bay

These are numbered 5 & 6.

These can't do integration
 

 Summing amplifiers are also known a voltage adders.

These circuits use op-amps to add.

Summers can be either inverting or non-inverting.

In any non-inverting summing amplifier, the output voltage is in phase with the input voltage.

This is a great circuit for adding two or more voltages without amplification.

Inverters

There are also 2 inverting only amplifiers at the very bottom.

They are numbered 7 & 8.

 

You can also see two multipliers above the inverting amps. They aren't numbered.

Here the output signal will be 180 degrees out of phase to input signal.

Notice the non-inverting (+ve) input is grounded and the feedback resistor connects to the inverting input.
Vout  = Vin* (R2)/R1

http://www.dvq.com/oldcomp/analog/comdyna.htm

+ https://www.grappendorf.net/projects/analog-computer/ 

 

THAT - That Analog Thing

The Anabrid THAT computer.

 

 Links

+ https://the-analog-thing.org/wiki/Main_Page

+ https://shop.anabrid.com/ 

 

Just purchased one of these.

 

 Its a Open Source Analog Computer

 By connecting the wires in different ways I can use it to solve all sorts of differential equations.

 

 

 

Analog computers have been around for thousands of years but over the last 70 years

they have been almost completely replaced with digital machines.

We must remember that the world itself is analog, not digital.

In the world of music, synths and electronics there is a constant battle between the two.

Do vinyl records sound better than CD's? 

Are vintage analog synths superior to digital keyboards?

Today, there is a resurgence in analog things and esp in analog computing.

The future, I'm sure, involves the utilization of both technologies.

 

The THAT computer is a great open source project and you don't have to spend a ton of money.

It looks like an easy introduction to analog technology.

 

So whats the difference between an analog and a digital computer?

The word analog comes from the word analogous or analogy.

An analogy is a comparison between one thing and another.

In a analog computer the comparison might be between the motion of a wheel and the

the rise and fall of a tide or changes in voltages and a weather model.

Digital computers, in comparison, use digits ... 

typically 0 or 1, on/off, true/false. 

 

Remember that analog and digital computers can be either mechanical or electrical.

For example, an abacus is digital.

A slide rule is analog.

 

Analog computers are relatively simple, use little power and are excellent at solving 

complex problems & differential equations. 

I doubt the THAT computer on its own, will be able to make music, but you should

certainly be able to interface it with a Serge or eurorack modular. 

Though I haven't tried this .....so a disclaimer if you do:

Do so at your own risk.

Anyway, I think this is an incredibly useful educational tool.

Moore's Law is reaching its limits. Quantum computing is only just beginning.

Maybe the near future of computing will involve hybrid analog/digital machines. 

Remember:

"There are more ways to solve a problem than the algorithmic approach". (Bernd Ulmann).

The THAT computer uses bananas. So I hope I'll find a use for this in some modular synths.

 

I'm not sure what size bananas it uses. Serge use 4mm diameter.

This might be 2mm ? 

Anabrid also make the Model-1 analog computer

and are working on building a analog computer that will fit on a chip.

https://youtu.be/j1wZ8zU1ZGI

 

Links

+ Basic op-amp circuits

+ ARP 2500 - 1047 Multimode Filter / Resonator

+ Integrator Circuit
+ CES Digital Systems Trainer - Ed-Lab 702
+ CSIRAC & Tec-1
+ Fairlight IIx Synth
+ Influential ICs  

+ TT 1  Turing Tumble

+ The Integrator Circuit - analog computers, Buchla, Serge & eurorack modules

+ https://analogparadigm.com/products.html 

Mixing Analogue and Digital Computers: The Future is Hybrid

 

 

ARP 2500 - 1047 Multimode Filter / Resonator

The ARP2500 filter/resonator 1047 module

It's a lovely sounding filter whos design evolved from analog computing.

 

 This module is a combined Low Pass, Bandpass, Highpass and Notch (band reject) filter.

All the filter outputs are available simultaneously in the lower section of the module.

This is why it's called a multimode filter.

 

I think the 1047 was one of the first multimode filters ever produced.

 

Resonance or Q, controls filter shape.  

Low Q settings give wider and smoother filter shapes.

They result in a gentle effect on the sound.

 

As you increase Q, the filter shapes become narrower & sharper. THis helps in focusing on narrower frequency bands.

As Q goes even higher "pinging" may occur, esp if you trigger the filter with a gate.

This is good for percussive sounds.

 The filters start to peak boosting some frequencies into overload territory.

 

 

 

 

 

 

 

 

 

 

These are the outputs and inputs

 

There are two audio inputs, two filter cutoff frequency control voltage inputs and two 

resonance inputs for CV control. The 6 pots are attenuators for these inputs .

 

What's really interesting about this filter is the bandpass section.

The 1047's band pass filter mimics that of a natural acoustic resonator.

Typical examples of natural resonators include strings, pipes, horns, drums.

The bandpass is a single pole 6 dB slope.

This gentle 6dB slop which lies on either side of the frequency cutoff point makes it

ideally suited for replicating things like drums, violins, etc

The filter can self oscillate as the resonance (Q) is turned up.

 

So you can patch a trigger into the filter and make it "ring" at very high resonance levels.

The input for your trigger is in the top right corner of the module.

 

The decay time of the ring is set by the resonance control. 

 

This filter design is how many analog drum machines

emulate sounds like Kicks and Toms.

You use the frequency knob to set the pitch.

I like to use a sequencer to automate varying the pitch while pinging the filter with a trigger/gate signal.

This ringing occurs as it's design is similar to mechanical resonators which ring when struck by an impulse of energy.

 

 

 

 

Turning the "Keyboard Percussion" switch to "on"  will connect the trigger output of your keyboard (or whatever other module is producing the trigger) to the audio input of the filter.

 

The Algorythm by Grayscale is excellent for this task.

 

 

 

Unlike earlier bandpass filters which simply combined LP & HP filters, 

The 1047 filter is an analog computing circuit consisting of summers and integrators.

 

If I'm reading the schematic correctly it looks like a State Variable filter.

 

 The state variable filter is a type of multiple-feedback filter circuit that can produce all filter responses simultaneously from the same single active filter design.

 

In programming a state variable filter/resonator on an analog computer, we'll need two integrators and one inverter connected into a loop.

 
You can see 3 op-amps (A1,A2,A3)
The last two use capacitors in a negative feedback loop -- they are RC integrators.
The first opamp is a summing amp.

Tapping the output of the first amp gives you the HP output.
Tapping the second gives you the BP output.
This BP out is fed back into the 1st op-amp, (non-inverting input).

Tapping the output from the third OP amp gives you the LP output.
This is fed back into the 1st opamp (the Summing amp)... the non-inverting input.

 

Filter frequency can be set both manually & with control voltages. 

The center frequency Fc of the band-pass output is the
cutoff frequency of the high-pass and low-pass outputs.
F c may be set by the coarse and fine frequency knobs
over the range of 16 Hz to 16 kHz.

There is also CV control over resonance.

With the resonance (Q) knob at minimum and the resonance switch set to "norm," the band-pass output has a gain of 0.5, and attenuates 6 dB per octave above and below Fc

 

 

 

 

 

 

 

When triggering, watch the overload light.

It indicates excessive input

 

Note that there is a resonance limit switch.

Setting it to "LIM" prevents signal overload when high levels of resonance are used.

 

 

 

 

Or the INPUT attenuator knob can be turned down

if the input source is the cause of the overload.

 

The switch effectively limits the height of a filter’s resonant peak. 

The LIM setting is preferred for signals which possess a strong harmonic or fundamental frequency.

 

----------------------------------------------------

The Notch Filter

This notch Fc knob is used to offset the notch filter’s center frequency (“fc”) set by the COARSE and FINE frequency controls. 

 

 The filter passes lows and highs, cuts out frequencies somewhere in the middle

 

 

The default setting for the notch filter is 1. 

 

In the pic above, the dial is fully counter clockwise. 

Thus the Notch frequency is shifted significantly below the filter's frequency cutoff (fc).

In effect, the notch filter is a copy of the high-pass filter. 

The reverse occurs if the dial is fully clockwise (ie past 4). 

The Notch frequency is shifted significantly above the filter's frequency cutoff (fc).

In effect, the notch filter is a copy of the low-pass filter. 

Notch filters can be used to create a faux phasing effect by modulating the cutoff with an LFO.

The notch filter is kind of like a high pass & low pass filter in parallel. 

The sound is quite cool, esp when sweeping noise

----------------------------

Links

+ EG & G Selective Amplifier model 189

+ Dennis Collins paper

 

For more info google:

 

stand-alone Analog Computation equipment used for Electronic Music

North America based companies EG&G (Edgerton, Germeshausen & Grier) and PARC (Princeton Applied Research Corporation) of New Jersey (Princeton roughly between New York and Philadelphia),


EG&G PARC model 121

 

 

 --------------------------------

ARP index

------------------

Happy Birthday George Boole.

 

This is a old serge module that performs Boolean logic. It's a form of algebra that is centered around 3 basic operators: OR, AND, and NOT. The core of Boolean logic is the idea that all values are either true or false. ... on or off.... 0 or 1.  From this idea, computers were born.

 

George Boole was born on this day (2 November) in 1815.

Though he only lived for 49 years he accomplished so much.

His legacy lives on to this day.

 

 

 

I came across this add , the other day reading an old copy of a Sci-fi magazine.

It's for a Geniac kit.

 

It's a very basic analog electro-mechanical "computer" that uses 6 disks.

It can do basic Boolean logic. 

 

 

You need to physically wire connections between an internal battery, the disks and some lightbulbs.

It doesn't have any form of memory, so can't perform sequential equations.

I don't think it has any latching circuits.

 

Links.

+Hackster

 

Willem Twee Studios - The Netherlands

This looks like a great studio.
Well worth a booking if you're in Holland.

Official website
https://www.willem-twee.nl/studios/

Facebook
https://www.facebook.com/willemtweestudios/?pageid=120494768636017&ftentidentifier=393452684673556&padding=0

There are 2 studios


Studio 2 has the Arp 2500s etc

Studio 1 has lots of test equipment


I'm particularly interested in the old analog computer


Melodic rhythms