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Location: Elk Elektronik - Shop 3, 266-268 Crown St Wollongong
JonDent - Explorations in Electronics, Electronic Music, Coffee, Sci Fi, Art & Travel (but mostly electronic music)
Saturday, 30 January 2021
Monday, 25 January 2021
NLC Mobius Pill - Build notes -part 1
These are my build notes for the Nonlinear Circuits Mobius Pill.
The MP is a chaos - noise module in Eurorack format.
So if you like chaotic noise this is for you.
The BOM looks pretty standard with no rare or hard to find parts.
You will need two 4046 ICs.
These are your PLLs (Phase Locked Loops).
(These PLLs create the chaos.)
There are also two Op-amps. These are standard 072s.
In addition to the two PLLs the circuit also has two vactrol based low pass filters
These filters are in the Buchla style... I think they are 292 inspired gate/filter combos.
The vactrols are all DIY (black box design) using LEDs and light dependent resistors.
The PLLs have a single combined voltage control input.
Each filter has it's own voltage control input.
Thanks to Andrew for supplying this diagram.
It explains what's happening in this circuit.
There are two TL072 op-amps, two VCOs, two filters , and two PLLs
The phase detectors feed into the LPFs and theirs outputs are fed into the non-inverting inputs of one and the inverting input of the other.
The outptuts of each control VCOs.
There are 4 inputs & 4 outputs.
Inputs:
Input signal, Freq CV, LPG1 CV and LPG2 CV.
Outputs
Two of the outputs are from the LPGs and two are from the PLL VCO
Some pics of the virgin PCBs.
LEDs go here. These LEDs are part of the vactrols.
---------
The 4046 IC -- it contains a VCO, two phase comparators & a zener diode.
The zener diode acts as a voltage regulator, setting the voltage at
5.1V. across it, for voltage input into pin 4. This is the voltage
that controls the number of oscillations for the output digital signal
of the chip
The oscillator will produce a digital square waveform .
Analog input to the VCO is at pin 9.
Digital output of a square wave is at pin 4.
This is fed into an op-amp and becomes the VCO 1 & 2 outputs.
PC (Phase comparator) 1 out (pin 2) becomes the LPG output.
Hopefully, this will help you trouble shoot, should you run into any probs.
The 4046s
First place the ICs,
Now the nineteen 100k resistors.
Rest of the resistors... Caps next.
the
The 1uF and 10uF need to be 25V or more.
To be continued ......Waiting for those diodes
Links
+ NLC Blog
---------------------------------------------------------------------------------------------------
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html
Andromeda A6 - Alesis Part 2 - Ribbon Controller & Performance Wheel
The Ribbon Controller
The Ribbon controller can be thought of like a pitch or mod wheel stretched across the keyboard.
As it has a much longer travel, its more accurate than a mod wheel.
It can be assigned to any of the A6’s mod destinations and is
programmable per Program like the wheels.
The MIDI Controller Number is user selectable
The ribbon can be assigned to multiple destinations at the one time and has 3 configurations.
1. Ribbon Value
2. Ribbon Left
3. Ribbon right
1. Ribbon Value
This assigns continuous values over its entire length.
2. Ribbon Left
This divides the ribbon in half.
The left becomes a self contained ribbon.
(There is a centre line).
3. Ribbon right
This divides the ribbon in half.
The right becomes a self contained ribbon.
The ribbon can also be a control route source .
Can be used to rescale any other modulation in a live performance
Ribbon HOLD Buttons
On each side of the ribbon there are HOLD buttons.
When ribbon hold mode is on, the
ribbon value will be “sticky”.
That is, when you lift your finger from the ribbon, it
will hold its value.
When you exit ribbon hold mode, the ribbon value will snap back
Programming the Ribbon Controller
1. Press the RIBBON button to the left of the ribbon controller.
This displays its control routes (CROUTES).
In the CRoutes display a Mod Route can be assigned
only one controller at any time.
Also, only 35 of the Mod Routes can be controlled from here.
2. Press soft button 1 (CROUTE).
You’ll now see a list of SOURCES on the left, going through a LEVEL and ENABLE
control, to a list of ROUTEs on the right.
3. To change the sources on the left (to either Ribbon Value, Ribbon left or Ribbon right),
turn the soft knob 1 or press the up or down keys when SOURCE is
highlighted.
4. Turn soft knob 5 (ROUTE),
(or press the up or down keys when ROUTE is
highlighted),
to display the destination.
To highlight ROUTE turn soft knob 5 very gently, then use the up/down keys.
---------------------------------------------------------------------------------
The Performance wheels.
The A6 has two performance wheels.
They are incredibly flexible.
These are mainly used for pitch bend (PITCH) and vibrato (MOD).
The Pitch wheel is on the left. It is a spring-loaded wheel that snaps
back to its center or neutral position when released.
The Mod wheel is on the right. It is not spring loaded and must be manually
returned to its off position.
It is normally used for vibrato.
Of course, you don't have to use these two wheels as described above. Eg you can make both pitch bend , both vibrato, swap them, neither, etc.
You can assign these wheels
to modulate any parameter that is designated as a mod destination.
You can even assign the wheels to perform multiple modulations at the same
time.
The pitch wheel is usually set up so that pushing it away from you bends played
notes up in pitch and pulling bends them down. This setting can be reversed.
It can also have a different type of
modulation on either side of the center stop.
Programming the Wheels
To make changes to either wheel, press the PITCH
(“Pitch Wheel”) ASSIGN
or the MOD (“Mod Wheel”)
ASSIGN button.
The parameters for that wheel will
be displayed
--------------------------
CHORDS
To define a chord,
hold down the CHORD button until the chord LED starts to blink.
Then, play the
notes of the chord and release the button.
After the chord is in memory, playing a single note on the keyboard will play the
chord relative to the note you played. To toggle chord mode on and off, simply press
the CHORD button.
+ Andromeda A6 - Alesis Part 4 - Filters, the post filter mixer
Saturday, 23 January 2021
Elk Elektroniks - synth meet 3 - 23rd Jan, 2021
Thanks to everyone who attended the synthesizer meeting yesterday.
Thanks also to Ed of Elk Elktronics for organising these events.
LOts of fun.
Lots of old and new toys.
Sorry about the background noise.
''
tHIS Korg Sigma is a really beautiful synth.
Underrated for sure
Hopefully, these meetings will grow as covid restrictions decrease.
NSW recorded no new local cases in the last 24hrs, and there is no one in ICU.
;-)
Looking forward to the next workshop in 2 weeks. (6th February)
I think this will be a second Elmyra workshop .
Time: 10am - 4pm
Location: Elk Elektronik - Shop 3, 266-268 Crown St Wollongong
Wednesday, 20 January 2021
Korg miniKORG 700 - vintage vs reissue
..
KITARO meets miniKORG 700FS
Kitarō (喜多郎), born Masanori Takahashi (高橋 正則)
(February 4, 1953), is a Japanese musician noted for his electronic-instrumental music. He is really famous for using this instrument.
Among his many achievements, in 1980, he received a Galaxy Award for the score of the The Silk Road: The Rise And Fall Of Civilizations It was a documentary on how ancient Japan was influenced by the Silk Road trade route.
The music was composed mainly using a Minimoog, Minikorg 700, and Maxikorg DV800.
I'm so looking forward to this re-issue of a classic.
I've had my old miniKorg 700 since 2011 and today decided to re-explore it in preparation for
the re-issue coming out soon. My version doesn't have midi, or CV control. There isn't USB connectivity, a sequencer, memory, or even a second oscillator.
It was released in 1973, retailing for $500 USD. (I paid $500AUD for mine in 2011).
The 700 was Korg's first monosynth but was released under the UNIVOX brand in the USA.
It has 37 keys, a 2-speed phaser, and a variable pitch slide.
To put this in context, the early 1970's was an important period in the development of the synthesizer.
The ARP 2500 came out around 1970, as did the Moog MiniMoog & the Buchla 200 series.
1971 saw the ARP 2600, the EMS Synthi 100 & Synthi A.
1972 saw the Buchla Music Easel, the ARP Odyssey (Mark 1), the Moog Sonic Six, The EMS Synthi AKS & Synthi E.
1973 saw the Moog Satellite and modular 15/35/55.
The Korg company had been around since the 1960's. They mainly made drum machines.
As mentioned earlier, this was their first mass produced monosynth. They were probably trying to cash in on the craze for pre-patched performance instruments like the Minimoog and Odyssey.
It started Korg's journey to become one of the world's great synthesizer manufacturers.
The knobs and dials share a common style with the minipops 7 drum machine.
Thanks bdu808
The Korg700 was meant to sit on top of a larger keyboard (usually an organ). Thus most of the controls have been placed under the keyboard, not above as is usually the case.
At first glance the 700 seems basic.
It has just one oscillator, a HP / LP filter, a simple EG.
But it delivers with style & has oodles of character. The filter (traveller) is fantastic.
Even with just one oscillator, it still can make some fat baselines.
The MiniKorg 700 was replaced a year later by the 700S.
This added a second oscillator and ring modulator. Korg is remaking the 700S but calling it the 700FS.
FS = Full Size. ??? Does this imply there will be a MiniKorg 700mini in the future ??
The FS has a second oscillator.
It also has a ring modulator, a spring reverb, joystick controller, patch memory, aftertouch and an arpeggiator.
I'm seriously tempted to buy this.
Some interesting features of these synths are the Traveller filter, the Percussion/Singing envelope, and the function switches.
The Filter
The Traveler is the Filter.
It's typical of early Korg filters seen in the 700, 700s and dv800 Maxikorg.
Korg also used this design in their FK-1 effects pedal.
These early filters consisted of high pass and low pass stages in series.
The top section is the LPF.
The bottom is the HPF
(interestingly, the Korg MS20 also used two filters - high pass and low pass in series).
Korg used the Keio IC TS201012 for the VCF.
It's a custom sealed IC. There are 2 of these.
The "Traveler" filter was used in the Korg 900PS, 700, 700S and 800DV.
To aid the filter there are 2 switches --
expand & Bright.
These add resonance
The "bright" adds additional high-frequency harmonics.
The Oscillator
Scale of course is the Oscillator Pitch.
You can choose waveforms with the mode switch on the right. You get Triangle, Square, Saw and Chorus I & Chorus II waveforms.
The Chorus I sound is described in the manual as a "Slow rotating sound with duplicating effect".
The Chorus II sound is described in the manual as a "Fast rotating sound with intensified duplication effect".
I understand that this single oscillator uses the KEIO TS200011 IC.
This is a Korg custom VCO core integrated circuit. (look for a sealed black box).
Check out Colin Fraser's website:
Colin Fraser in 2010 began reverse engineering these
modules. Before this you had to "sacrifice" old Korg synthesizers to get spare parts.
The Envelope Generator
Attack on the left. (forms the beginning of the note)
Decay on the right. (Forms the end of the note).
The Decay range is from
Short (Percussion) to long (singing).
The envelope is triggered by the keyboard.
When a key is pressed the cycle is initiated.
The envelope is disengaged when the key is released.
To enable a show release when a key is released,
activate the the sustain switch.
The sustain level is fixed.
The Bender provides added slide to the beginning of each tone... such as Glissando and slur.
It glides into the current note, from a whole tone below.
The Portamento switch in comparison glides the previous note into the current note. (A bit like a slide).
Repeat - this repeatedly triggers a held note.
Vibrato - It modulates the pitch of your current note.
Delayed Vibrato - applies vibrato with a slight delay.
The amount of these last 3 effects (repeat, Vibrato, Portamento) are controlled
with the slide modifier group below. The green slider adjusts the portamento speed.
The two blue sliders control the speed & depth of vibrato.
The pitch slider on the far right on the above picture is the master tuning.
Just two audio outputs - High & Low.
There is no CV control or midi of course.
Also no external filter input.
Links
Tuesday, 19 January 2021
Korg WaveState - category selection, set lists
Menu diving on the Wavestate can be a bit confusing.
Picking sounds for each layer is easier if you understand how the wavestate
divides the sounds into categories.
1. Pick a layer. (A, B,C, or D)
2. Go to the performance page.
The top box is highlighted.
3. Press the right arrow >
the cursor will go to the next box down
4. Turn the value knob
5. Press SHIFT and >
You will now enter the category section.
The Filters & Sort Order page appears.
Select the Category or Collection parameter, and turn the VALUE knob or press ENTER.
Monday, 18 January 2021
Andromeda A6 - Alesis Part 1 - Basic intro
This is part of my exploration of the Andromeda synth.
It's
a wonderful synthesizer, which even after owning it for over 5 years
I'm still just scratching the surface of what it can do.
The A6 is intimidating at first glance. 72 knobs, 144 buttons, 16 voices, 16 VCAs.
There are 2 oscillators and 2 filters per voice. (That's 32 VCOs & 32 filters)
The filters are a multimode 2-pole and a 4-pole lowpass.
The
official manual is really long (as you'd expect) from such a complex
synth, so this is my attempt to break things down, into smaller parts
for myself. If this helps someone else, that great too.
Let me know of course if I have made any mistakes. I'll correct them ASAP.
The overall signal path runs from left to right.
Each VCO has 5 waveforms (sine, triangle, square, up saw, down saw).
There are three LFOs, each with six waveforms and they can be synced to MIDI clock.
And there are three 7-stage envelopes.
There is a built-in
arpeggiator and 16 step sequencer with MIDI sync.
Effects -
Digital reverb, chorus, echo, analog distortion, quad pitch-shifting, flange, and more
Memory -
Program Memory: 256 preset and 128 user-defined
Mix Memory: 128 user-defined
Memory Card Slot: PCMCIA-format
Mix Memory: 128 user-defined
Memory Card Slot: PCMCIA-format
I think the best way to view this synth (and the same goes for any synthesizer) is to
break it up into it's parts. Imagine this as you would a modular synth.
The A6 is made up of VCO's, Filters, Mixers, VCAs and EGs.
In fact the Andromeda is very much like a modular synth.
You can “disconnect” some of these modules from the audio
and control paths by
setting their values to zero, in effect turning them off.
It's really easy to view the settings for each module and see how they are
connected to the other modules.
For such a complicated beast, it really is quite logical and not difficult to use
once you grasp the architecture.
-----------------------------
Setup.
Before we begin, lets make sure the synth is tuned. Press the auto-tune on the extreme left.
(you need to press this button twice)
The LED will flash and the display will show the status.. that the synth is tuning filters, VCOs etc.
This takes a few minutes.
The A6 operates in
one of two play modes: Program mode and Mix mode.
They are really just two types of presets
Program mode:
The
keyboard plays a single sound across the entire keyboard.
Program mode has 3
banks: User, Preset 1, and Preset 2.
There are two banks in Program mode (one User and one Preset)
Each bank has 128 different Programs, so you
have a total of 256 Programs to audition.
You can move among Banks by pressing the < BANK > button
To select a Program, make sure that the A6 is in Program mode: the LED next to
the PROGRAM button should be on. If not, press the PROGRAM button.
Program mode also contains a third function called MANUAL
This is used
when creating new Programs. It is only active in Program mode.
Pressing this
button causes the A6 to exit the current Program and create
a new Program based on
the current settings of all front panel controls.
It
provides a good starting point for a new program.
Mix mode:
The A6 may play different sounds
in different ranges (a split), a stack of sounds on top of each other,
or combination of
splits and stacks.
There are two banks in Mix mode (one User and one Preset) for a
total of 256 Mixes.
To select a Mix, make sure that the A6 is in Mix mode: the LED next to the
MIX button should be on. If not, press the MIX button.
Mix mode is also used when the A6 is connected to a MIDI sequencer for
multitimbral recording and playback. Each Mix channel can be assigned to a specific MIDI Channel
with unique MIDI controller assignments.
The row of rectangular buttons just below the display area are used to select the
Programs within a Mix. When a Mix Channel is ON, its associated LED will light.
When a Mix Channel is currently selected for editing in the display, its LED will
blink.
Presets
Called "programs" or "mix" here.
Press the program button (or mix) + ten's + ones
You can also use these left two knobs to scroll the programs, banks & DIRectories
and the two buttons on the right (see pic).
If you wish to write a new patch, press the red "store" button.
Compare - compares the edited patch.
Manual - resets all parameters according to the front panel settings.
In fact the A6 is littered with them on the LFOs, filters, VCOs, EGs Mixers, ARPs etc
This is what makes the A6 behave like a modular synth. You can view each module in isolation.
Pressing these buttons will display the settings of that module on the display.
Oscillators
We have 32 oscillators spread over 16 voices.
Two per voice.
These are the controls for a voice.
You have the two main oscillators, two sub oscillators, external input, noise, ring mod, filter feedback
Press the mixer view to get a overall idea of the various audio inputs
You can mix oscillator level, noise, external inputs,
The oscillator view button brings up a view of that VCO in question
yOU can play with PWM and levels, turn on /off the different wave shapes, etc
Filters
Filter 1 is a 12db multimode 2-pole.
Filter 2 is a 24db 4-pole lowpass.
When filter 2 input is set to mix, both filters are working in parallel.
That is, both filters are independent.
Thus the LP,BP, HP of filter 1 & the LP of filter 2 are all available
at the same time.
You can mix both filters plus the pre filter.
Pre filter includes Osc 1 sine, OSC 2 sine, & Ring mod
Envelopes
There are 3 with 7 stages per voice
When you touch any of these knobs or buttons, the associated envelope will be displayed on the screen.
They have delayed onset, attack, two decays, sustain & 2 releases.
You can loop selected stages.
There are 3 possible modulations for each envelope.
LFOs
There are 3 LFOs.
Each LFO can be sine, tri, saw, square
You can change the freq, polarity, phase
and of course the source & destination.
eFFECTS
tHIS has two parts:
Analog distortion & Digital effects
The digital effects include: chorus, delay, reverb
Clock
This sets the timing for the arp , sequencer, LFOs
------------------
I understand that the name 'Andromeda' comes from The Andromeda Strain.
It's a 1971 American science fiction thriller film produced and directed by Robert Wise. Based on Michael Crichton's 1969 novel of the same name.
It's about a deadly alien organism that when it infects, crystalizes the blood.
--------------------
I'll go into greater depth in future posts. J
+ Andromeda A6 - Alesis Part 4 - Filters, the post filter mixer
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