JonDent - Exploring Electronic Music

Tuesday, 2 June 2020

Triggers & the mOOG 961 INTERFACE

.... iT'S interesting that old Moog Modulars use both S-trigs & V trigs.

Triggers might be produced by sequencers, the key on a keyboard, drum controllers & foot pedals.

They are useful for starting an envelope generator or advancing a sequencer.

A S-trig is just a passive switch closure to ground.The voltage starts high, and when the trigger occurs the voltage shorts to ground. It's also known as a switch trigger or shorting trigger.

Moog Keyboards produce S-trigs.

Moog 911 Envelope Generators need S-triggers to start their cycle.

In comparison, V-triggers start at zero volts and rise to a standard level .. usually 3V.

The 911 plugs into the Moog modular using a 22 pin PCB/edge card connector.

It's a ADSR envelope generator.

The pin out is as follows:

1. +12V

2. GND

3. -6V

14. Trigger out
21. to Trigger switch (Jones S-302)

The Moog manual suggests a regulated AC supply, such as a Moog Model 901 or dry batteries.

Max current is 50 milliamperes.

Range of T1: 10 ms to 10 secs (attack)

Range of T2: 10 ms to 10 secs (delay)

Range of T3: 10 ms to 10 secs (Release)

Range of Esus: 0 to Emax

Esus = sustain.

Emax = voltage at which T2 begins. = 5.5V +/- 10%

You trigger the 911 by closing a switch. So unlike most EG's you will encounter today, no voltage is supplied to trigger the module ... its quite the opposite.

The 960 sequencer produces V-triggers.

V-triggers start at zero volts and rise to a standard level .. usually 3V.

In the Moog Modular world, the S-trigger uses a special 2 blade Cinch Jones connector.

The V-trig uses the standard 1/4 inch jack.

So how do you get a trigger from the 960 sequencer to start a envelope cycle of a 911 EG.

To convert triggers from one to another, you can use a special conversion cable or the 961 interface

There are 2 types of this module..... the P (portable) and the C (console).
The above module is the P-type ... used for portable systems.

This is a audio to V-trig converter.
Plug in any audio source (like an old drum machine) into the jack on the left.
It will be transformed into a voltage trigger.

The control is a sensitivity knob.
The console version has this section right at the top of the module.

This is the V-trig to S-trig converter.
My module, has been modified somewhat, so may look a bit confusing. However, the V-trigs (from your 960 sequencer) enter into the jacks on the left, and S-trigs exit via the dual blade Cinch J plug.

There are 2 input sections: A & B
Any inputs into column A will have the same duration as the outputs
The Column B in jacks are connected to a Switch-On Time knob.

This allows you to control how short or long the “ON” duration is for S-Trig signals. (40ms to 4 seconds). You can use this to trigger the 911 envelope generator.

Links

+ Modular Synthesis

+ Here are the Mouser links for the Moog connector hardware:
https://www.mouser.com/ProductDetail/571-5-530501-5
https://www.mouser.com/ProductDetail/571-582388-9

Moog models using the S-Trigger system

Moog Modular System 15
Moog Modular System 35
Moog Modular System 55
Moog Modular System 3C
Minimoog Model D
Moog Sonic 6
MicroMoog
Moog Liberation
Moog Source
Moog Taurus
Moog Prodigy
Moog Rogue
Moog Sattelite
MinitMoog
Moog Ribbon Controller
Moog Sample & Hold Controller
Moog Drum
Moog 1130 Drum Controller
Moog Modular Keyboards
Moog Mother 32 ??

Alesis DM5 - Pioneer Squid

qUITE a handy drum rack.
The 1U module can be triggered with MIDI & analogue triggers.

How to recall Drumsets
The DM5 has 21 Drumsets available, each of which has 61 programmable drum sounds.
To recall a Drumset on the DM5:
1. Press DRUMSET
2. Turn the VALUE encoder to select a Drumset

Editing The Triggers
The DM5 has over 500 drum sounds arranged into 8 Families.
These consist of Kick, Snare, Toms, Hi-Hats, Cymbals, Percussion, Effects and Random Samples.
To assign a new Voice to a MIDI Note or External Trigger Pad:

1. Press VOICE, then press NOTE CHASE
2. Play a note on your MIDI controller or a Drum Pad
3. Press the CURSOR> button until you have selected the Voice Family parameter on the top left corner of the display. Choose one of the families listed above using the VALUE wheel
4. By pressing the CURSOR> button one more time you can then select one of the Voices in that Family using the VALUE wheel

Triggering with MIDI
Using the Pioneer Toraiz Squid

Looks like there are 12 triggers.
Set up midi channel (using channel 1 in this case)

To choose the Drumset, press group then voice on the Alesis drum.
You scroll through the sounds with the pitch /cc knob on the squid

KIK 36 C1 (C2 on the Toraiz)
Snare 40 E1 (E2 on the Toraiz)
Tom 41 F1 (F2 on the Toraiz)
Clap D#1 (D#2 on the Toraiz)
Hat F# 1 (F#2 on the Toraiz)
Cymbal C#2 (c#3 on the Toraiz)
Tambourine F#2 (F#3 on the Toraiz)
Cow Bell G#2 (G#3 on the Toraiz)
Vibrslap A#2 (A#3 on the Toraiz)
Ping Ride B2 (B3 on the Toraiz)
Cym SternDark A2 (A3 on the Toraiz)
Bongo Hi C3 (C4 on the Toraiz)
Cym Splash G2 (G3 on the Toraiz)
Anvil C#1 (C#2 on the Toraiz)
Clank G#5 (G#6 on the Toraiz)
Cuica Lo G4 (G5 on the Toraiz)

The main out is the left out at the back.

Monday, 1 June 2020

My Son - Hindu Temples - Vietnam

This is a collection on Hindu temples in Vietnam.
It's really odd to see this kind of architecture outside India.

It's near the source of the Thu Bon river..... which flows to Hoi Ann.

The temples date between the 4th to 13th centuries.

Much was destroyed during the Vietnam war.

Links
+ My Son Temples - UNESCO

Thursday, 21 May 2020

Moog Modular - 901 VCO

This is a 3MU module.
The Moog 901 came out in the late 1960's .. possibly 1965 to 68 ??
It's what is called a first generation VCO.
You can use this as a VCO & VCLFO (voltage controlled LFO)

It's a classic, and arguably this oscillator has influenced all VCO designs..... not just of Moog, but of synth manufacturers from around the world.

Below are VCOs from a ARP 2500, a Korg MS 20, and 3 Eurorack manufacturers.

The 901 is basically a 901a + a 901b in a single panel.
I understand it was the precursor to the 901a/b/c/d (please let me know if I'm mistaken).

There are 4 fixed outs .... sine , saw, triangle, pulse. ,.... all available simultaneously.
Level of these fixed outs is 0.5V RMS (-4 db).
600 Ohms impedance.

Sine:

Saw:

Triangle:

Pulse:

There are also 4 variable level outputs... which opens the window to mixing the different waves in varing amounts and sculpturing new waveforms.
Their range is 0 to 0.5V

There are 3 CV inputs.
There is a CV span of -4V to +6V according to the manual.
I like to keep it within the range or 0 to +5V

The frequency span of the VCO is 0.1 to 15Khz
There are 6 ranges: Lo, 32", 16", 8", 4", 2"
(Lo is good for LFOs)
The tuning of these oscillators definitely drift... but it's part of their charm :-)
I've read that Wendy Carlos had to tune them again and again while recording.
It might be the stability of the power supply ??
The manual states that keyboard tracking is a full 5 octaves... though I think maybe 2 octaves is more
reasonable. Still I love their sound.
Any temperature variations will cause large fluctuations.
Power supply requirements: -6V , +12V regulated.
-10V unregulated.

This is the view of the rear.
The PCB mates with a 22-pin connector.
(Tyco Duo-Tyne flag 22 pin edge connector)
The connections are
1. +12V
2. Ground
3. -6V
9. Sine out
11. Triangle out
12. Pulse out
14. -10V
16. Sawtooth out

Below is a pic of the 901a & a series of 901b modules
The VCOs were designed to work in banks, with a single 901A oscillator driver module.

In this pic, there are four 901b oscillators being driven by one 901a controller.
According to the manual, up to twelve 901b oscillators can be chained to one 901a controller.
The idea behind this was so just one set of CVs (from a keyboard for example) could drive a bank of 901B VCOs and they would track nicely together.

901A controller module
There are no output jacks. Only CV inputs.
There is a CV span of -4V to +6V according to the manual.
I like to keep it within the range or 0 to +5VPower supply requirements of the 901a : -6V and +12 V regulated. Max current is 25ma.

The PCB mates with a 22-pin connector.
The connections are
1. +12V
2. Ground
3. -6V
5. This connects to the corresponding number on the 901B
6. This connects to the corresponding number on the 901B ???
7. This connects to the corresponding number on the 901B
9. Control input jacks
10. Control input jacks
11. Control input jacks
12. Control node

901-B Oscillator

Each 901B module has 4 output jacks ... one for each waveform.
Saw, tri, sine, pulse .
The amplitude of each waveform is 0.5V RMS

sAW

Sine:

Pulse

Triangular

Oscillator 901B connector pinout.
The PCB mates with a 22-pin edge card female connector.
The connections are
1. +12V
2. Ground
3. -6V
5. This connects to the corresponding number on the 901B... "A"
6. This connects to the corresponding number on the 901B... "C"
7. This connects to the corresponding number on the 901B... "B"
9. Sine out
11. Triangle out
12. Pulse out
14. -10V
16. Sawtooth out

Tuesday, 12 May 2020

Korg - Index

Saturday, 9 May 2020

Korg Volca Beats - midi mapping

The Volca Beats is a cute but powerful drum.
Perfect for live performance. The sequencer is a bit limited. so midi mapping to an
external sequencer would be useful.
I'm using the Pioneer Toraz Squid as my midi sequencer.

So the volca doesn't start playing the moment you start the Squid
you need to enter the Global function setting.

1. Start the Volca while holding the func key, wait for it to start.
2. press step 6 (the light should go off), press Rec.
Now the sequencer will not start when you press play in your DAW or your Midi sequencer.

(It looks like the default midi receive channel is 10... the same as the Roland 707 & 909).
I'm leaving it as it is.

If you wish to change the midi receive channel:

1. While holding down the MEMORY button, turn on the volca beats.
2. Step buttons 1 to 16 correspond to the MIDI channels 1 to 16.
    Press the button that corresponds to the desired channel, and the LED below the
    step button will light up
3. When you have ﬁnished specifying the settings, press the  (REC) button.
     The settings will be saved, and the volca beats will be restarted.
     If you decide to cancel the settings, press the  (PLAY) button.

Also in the Global setting
1. Start the Volca while holding the func key, wait for it to start.
2. Press step 7. MIDI RX ShortMessage
     Set to off (St.oF)
3. press Rec. to save

There are 10 voices to map

1. kick C2
2. Snare D2
3. Lo Tom G2
4. Hi Tom D3
5. CL Hat F#2
6. Open Hat A#2
7. Clap D#2
8. Claves D#5
9. Agogo G4
10. Crash C#3

Renaming projects in squid
* use the shift, main knob, Track Button & back button ..
Press shift + press main knob = space.
Shift + back = delete
arrow keys move forward & back
* shift + Track --- you can rename tracks, change their colour, etc

-------------------------------------
*** The Volca sample has a different midi implementation to the Volca Beats.
In the Sample, each voice has its own MIDI channel. ***