Friday, 3 July 2020

Synthesizer Logic Modules - The 7 gates

Logic gates are great ways to create interesting rhythms or combine triggers from various sequencers.
Recently I've been using them to trigger drum modules.
Some logic gates also work at audio ranges.
There are 7 basic gates: OR, XOR, AND, NOT (inverter), NOR, XNOR, & NAND.

To make things even simplier, the 3 basic fundamental gates are OR, XOR, AND.
They use the inverter (NOT) to make NOR, XNOR, & NAND.
 
One final grouping of gates is what is known as Universal Gates
A universal gate is a gate which can implement any Boolean function without need
to use any other gate type.  
The NAND and NOR gates are universal gates.
These 2 gates are the basic gates used in all IC digital logic families. 

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


OR gates
Output a high signal whenever one or more of its inputs are high.
Useful if you wish to combine several gate signals into one.

You can use this instead of a mixer or multiple.




 In1 In2 Out
 0         0 0
 1 0 1
 0 1 1
 1 1 1


XOR Gate (Exclusive OR gate)
Will only output a high signal when one input is high and the other is low.
It allows the signals to pass Except when they happen simultaneously.
It's like when 2 people try to squeeze through a narrow door at the same time.
(use this for your two snare drums - to prevent them triggering simultaneously)




 In1 In2 Out
 0         0 0
01 1
 1 0 1
 1 1 0

AND gate
Outs a high signal when all its inputs are high.
(If only one input is high it will output a low signal)




 In1 In2 Out
 0         0 0
 1 0 0
 0 1 0
 1 1 1


NOT gate
The above 3 gates are available as inverted versions (N = not):




 In Out
 1 0
 0 1


OR -----> NOR
XOR -----> XNOR
AND-------> NAND

NOR Gate
This is a OR gate followed by and inverter.
This is quite a useful gate to have, as it's possible to build the other basic logic gates
using only NOR gates.




 In1 In2 Out
 0         01
 0 1 0
 1 0 0
 1 1 0

Its output is "true" if both inputs are "false." Otherwise, the output is "false."

XNOR
This is a XOR gate followed by an inverter




 In1 In2 Out
 0         01
 0 1 0
 1 0 0
 1 1 1


NAND Gate
This is a AND gate followed by an inverter




 In1 In2 Out
 0         0 1
 0 1 1
 1 0 1
 1 1 0

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

For most Eurorack modules:
Low signal = 0V to 1V (usually)
High signal = greater than 1V to 5V (Usually)

Many logic modules respond to continuous CVs like LFOs .
They are reading the CV as a high gate when it exceeds 1V (usually) and a low gate when it is below.
So they can be used as comparators with a fixed threshold.

The logic synth modules you can buy or build will either use discrete diodes, transistors & resistors,
or use integrated circuit chips. TTL and CMOS are the most common types of ICs.
TTL IC’s may often be labeled as the 7400 series.
CMOS ICs are commonly marked as 4000 series.


Eurorack Logic Modules
+ Elby ED132 - Boolean Logic (Also a Serge Version)
+ Erica Synths - Pico Logic
+ Mystic Circuits ANA
+ Intellijel OR, Plog, Spock , uMod II
+ AniModule  LogicOgic, XX_OR
+ 2HP - Logic
+ Mutable Instruments - Kinks (OR & AND gate)
+ Doepfer A-166 (Dual Logic Module) .... AND, OR & NOR, plus two inverters.
+ NLC - Bools, Neuron, Chopper, 8 bit cypher,
+ CGS Funky Drummer
+ CGS Boolean Logic
+ EMW Logic 101, Logic 202
+Wiard /Malekko - JAG
+ Snazzy FX Ardcore
+ Synthrotek - Either-OR Eurorack OR Module
+ Pittsburgh Modular - Logic Banks
+ Analog Ordnance - Logiplex, OR gate,
+ Ladik B-010 Bool2, B-020 Bool3,
+ Circuit Abbey - ANDY, ORY, XORY, VERTY
+ Synth Cube Dual Logic
+ LZX - Castle 100, Castle 101
+ Pulp Logic (1U tiles) -Logical AND, OR, Diode-OR, XOR


Plog - Intelligel
This has AND, OR, NOR, XOR, NAND, and XNOR gates
RYO
NOT, XNOR, NOR, OR, NAND, AND


Links

Fairlight IIx - instructions for using the HxC SD reader

The  HxC SD card reader is an excellent addition to your old Fairlight.
The HxC is a Floppy drive emulator.
The Floppy disk drives are 40 years old and hard to maintain, repair & replace.

I highly recommend you email Jean-Bernard of MUSTUDIO for one.

I purchased the kit from mustudio.fr
Many thanks also to Peter W for his help in it's installation.
The Flash player uses a SD card to emulate 2 virtual drives. (A & B).
Compatable cards are SDHC up to 32MB.
Formated in FAT 32.... use a PC (not a MAC) to format the card.

I found navigation of the file structure in the SD card a bit confusing at first.
The left and right black buttons allow you to scroll through the choices. 
The RED validation button is to confirm your choice. 

In order to enter the MENU (configuration mode), press and hold the RED validation button for a few seconds, till a  menu item (System, Sound or QDOS) appears on the LCD display.


This is how it seems to be set up:

You only need to use the "Systems" and the "sounds" sections.

The original CMI uses two floppy drives (Drive 0 & Drive 1)
One handled the operating system, and the other handled the sounds.

To install the SD card reader you need to remove one of the floppy drives.
The card reader has 2 toggle switches that let you choose how the CMI picks which drive to use.
The SD card can behave as two virtual drives, or act as just one virtual drive allowing you to
still use the remaining floppy drive.
So my CMI can now boot or load sounds from the SD card alone 
or a combo of the SD card & the single remaining floppy drive.

There are 3 possible switch combinations:
1. S2 up, S1 up
2. S2 up , S1 down
3. S2 down, S1 up.

The 2 toggle switches (S2 & S1) must be in the correct position.

I like to configure the system to use two virtual drives (setting number 2).
That is, I'll bypass the use of the Floppy Drives completely.
Left switch (QFC9 or S2) : up
Right switch (Flash or S1): Down


1. Turn on the Fairlight.
    The monitor will as is usual display "Load System disk in drive"
  

2. "Systems" should be shown on the display.
  
      If not, use the left/right buttons to rectify till you find "systems".
      (pressing the left/right buttons will move you between Systems, Sounds & QDOS)



3. Hit enter when you see "Systems" (the centre red button)
    You should see two dots "  ..  "
4. Using the right button, step through till the desired software is shown.
    (Revision 20).  V4 C5 R1 20
    Hit enter.

    The Fairlight will now load the operating system
    It bleeps as it steps through sectors. The monitor should eventually show Page 1

5. Hold down "Enter" (middle red button) for a few seconds.
    The LCD will change... You are entering the "Function Menu" Mode.

6. Toggle through options till "change drive" appears.
     Hit "Enter"


7. Toggle until "B" appears.


    Hit Enter


8.  The LCD display will show the software revision.

 
Toggle left until only dots appear.
Hit enter


9. Systems should reappear.   

10.  Toggle left till "sounds" shows.
       Hit enter
(You are now in the sounds folder)
You will see those two dots ".." reappear
 


8. Step through till the desired library is found. (I normally use 1.3)
    Hit enter
(You are now in the 1.3 folder)
You will see those two dots ".." reappear
 
8a. Now to load one of the folders within folder 1.3
     you need to press the right button.  Each press will take you to a new folder.
     The first folder is called 1. The next one is 10.
     I've set up folder 10 to start things off. Use this.
     Note: once you have found folder 10, press the red button on the card reader.
   


9.   Now use the native Fairlight alpha/numeric keyboard itself.
     On the Fairlight go to page 2.
     (Type P2)
      You should see displayed the contents of the virtual disk.


10. Toggling left & right  on the SD card reader should show the contents of each virtual disk.

This is library (or virtual disk) 15



Test by loading a file.
EG:
Type L,A,filename<return> to load a file.

eg to load a file named GONG1.VC
type L,A,GONG1 <return>
You don't need to add the .VC after the file name. 

Wednesday, 1 July 2020

Roland / Studio Electronics SE - 02 envelope

I'm revisiting my SE -02 synth .
The Studio Electronics / Roland Boutique synth has a rather unusual envelope, which is kinda borrowed from the Moog Mini D.
It's not a clone of the Moog, though I thought it would be useful to compare the two.

The most common type of envelope is the ADSR.

It has 4 stages. The stages are:
Attack : is the time taken from nil to peak, beginning when the key is pressed.
Decay : is the time taken from peak to the sustain level.
Sustain : is the level during the main sequence of the sound's duration
Release : is the time taken from the sustain level to zero after the key is released

The Mini Moog D was unusual in that there were just 3 knobs to control a 4 stage envelope.
Most synths have 4 knobs.
Attack, Decay & Release are all time based.
Sustain is a voltage level. It is usually "flat" and does not change during it's phase.

Usually the envelope starts with a signal from a keyboard or other source. It goes through the attack & release stages. When it reaches the sustain phase, it pauses and remains there until the gate goes low (e.g., from the keyboard key being released).



There were two identical envelopes ...  one for the filter, and one for the amplifier

The decay knob doubles as the release knob.
So the envelope can be seen as a ADSD envelope.

It's interesting though not surprising that Studio Electronics decided to use a similar envelope configuration.
My SE-MidiMoog (which is a rack mounted Model D) started this all off.



The SE-01 & SE-1X saw the return of that release knob, but the SE02 saw it's demise once again.
 SE-01

Maybe the decision to drop this pot, was based on practical considerations like the lack of space on the Roland Boutique synths.

SE-02

So looking at the front panel of the SE 02 one can see we have 2 envelopes:
A Filter and a Amp envelope.
Neither envelope has a release knob. They both however share a release switch
which is in the the lower right corner.
It's settings are: 2, 1&2, OFF
2 = The release stage is applied to the Amp
1&2 = The release stage is applied to both the filter & AMP
OFF = No release stage

Remember that the decay value = release value.

----------------
About the other knobs & switches in the Filter/Envelope section:

Key Track
1/3  = The filter frequency changes by 1/3 of the pitch change.
2/3  = The filter cutoff frequency changes by 2/3 of the pitch change.
          If both switches are on, the filter cutoff frequency changes by the same amount as
          the change in keyboard pitch.

Contour
Adjusts the amount the filter envelope effects the filter frequency.

Normal / Invert switch
Specifies the polarity of the filter envelope that is controlled by the [CONTOUR] knob. If this is set to “INVERT,” the polarity is inverted.

Mtrig switch
If this is on, the filter envelope restarts each time you press a key.

LFO/GATE
Specifies the signal that controls the amp envelope.
LFO: The LFO controls the amp envelope.
GATE: The Note or Gate controls the amp envelope


Links

Studio Electronics SE -02 / Roland - Transposing sequences with the keyboard

The manual is a little confusing.

When I first attached a keyboard to the SE-02, it appeared thAT i couldn't transpose
any stored sequences.



To do this you need to enter SETUP.

While in sequencer mode
1. Press NOTE & GATE simultaneously
2. Press the 3rd STEP button
3. Rotate the VALUE knob till the display shows trn (The default is OFF)
   trn = transpose
4. Press the VALUE button (3 times)
    You will be prompted with the message "sure",...



Pressing this "value" knob is also how I save patterns.
The presets occupy memories 0-87.
88 is clear for your first patch.


The problem with this method is that the sequence will only sound while you are pressing a key.

-----------------------------------------------------------------
A second method for transposing the sequence is
1. start playing your sequence while in SEQ mode.
2. Switch to PATCH mode while the sequence is still running.
3. press the TRANSPOSE button
4. Press OCT- or OCT+ to transpose up and down an octave


Saigon War Remnants Museum -Vietnam

This was first opened just after the end of the Vietnam War in 1975.
It was originally called the ‘Museum of American War Crimes’.


Quite a confronting place.

The effect of war on both the combatants and civilians is brutally displayed.
I left with a feeling of intense sadness.



For war memorabilia enthuasists there is lots to see ... helicopters, tanks, fighter aircraft.. etc









But the photos upstairs in the building tell another story... the human cost








For more travel postcards click here:
 

Saturday, 27 June 2020

Julia Bondar - Live rig

 One of my favourite Electronic Music artists is Julia Bondar.
I have never seen her live. Hopefully one day I will.
 
In addition to producing very danceable  electronic music, she is the co-founder of
Endorphin.es.
 I bought one of their early eurorack modules I think 10 years or more ago,
A FuthRRRR generator
 
 
 It had the label: Vienna/Austria, though I think the company is now based in Barcelona, Spain.


It's inspired by the Buchla 259


Anyway, getting back to her live Euro setup:
It mainly consists of Endorphins.es modules.
She does use a Arturia Beatstep Pro as her main sequencer and a Roland system 1M.
The compressor she uses when performing live is a TC Electronics Finalizer Express.

The Modules as of 2020/21 are:
Milky Way x 2 --- stereo effects/VCA
Cockpit x 2 -- 4 channel performance mixer with send/return & compressor
Squark Dirty - filter
Airstreamer - envelope generator - AD or Looping ASR
Godspeed - VCO
Autopilot - vco tuner           
Sample Drum - Erica Synths
Magneto - Strymon - delay
Shuttle Control x 2 - MIDI/USB & PSU

FurthRRRRRRRRRR Gen - VCO
Running Order - two track trigger sequencer/euclidean/clock divider/
Queen of Pentacles -- 909 drums

Grand Terminal - two multifunctional dual function generators
                            (they can loop and become oscillators), 
                            2 filters -Transistor Ladder/ resonant LPG/diode ladder/
                            vactrol LPG/State Variable LP/HP/BP/Comb
                            FX processor/generator.
                            You can use this module as a full synth voice. 

The Main Audio seems to come from the Furthrrrr Generator & Grand Terminal.
The bass lines come from the Roland System-1M (SH - 101 plug out) & Godspeed.
 
A good "Bass voice" is the 
Godspeed VCO>Squawk Dirty VCF>Airstreamer EG>Milky Way FX/VCA
 

Her Modular Grid link is here:

--------------------------------------------------------------------
28/06/21
Since the last post her rack has changed slightly.
(Spring 2021)
Julia is has swapped one of her shuttle controls for a Ground Control.
She is now using this instead of the Beatstep ??

Looks like the Roland System 1-M is still there.

There is also a "Golden master" -- EQ, Compressor, side processor etc 
There is a mutable instruments clouds, a total recall (CV preset manager) & a two cups (sample player)
The case has also dropped the Strymon Magneto & the Auto Pilot.

The new case is an Intellijel Stealth.