These are my build notes for the Shock Electronix Eurorack conversion of the Korg
Monotron Delay.
I remember modifying my monotron back when they were first released. So much fun.
Matt from Rhythm Active has done some great work in producing this kit.
Its very easy to build.
BOM
Resistors:
100R x 1
390R x 1
270R x 1
33K x 1
Diodes:
1N4148
Capacitors:
100n
10uF electros
First open up your Monotron Delay.
Lots of surface mounted components. You could hack from this surface to (a future job) but Korg have helpfully placed the patch points on the rear.
I love the people at Korg. They have even made the schematics freely available.
Delay schematics are here.
Back to the build.
Resistors first.
Friday, 18 December 2015
Wednesday, 16 December 2015
Buchla Easel - Program card map for BEMI, Vintage & Rev II 208s
Some maps to help navigate the Buchla Easel program/patch card.
These first 2 pics are for vintage & rev2 versions (not the Rev 1).
1. +15V 15. sequencer (out) B ?? (different to tab13F ??)
2. Gnd (Quiet) 16. Random out
3. ? ("rng" on the BEMI card) 17. Envelope trig in
4. ? 18. Pulser out A
5. ? 19. Env Duration (sustain on the BEMI card) in
6. ? 20. Pulser out B
7. Voltage Level - Step 1 (in) 21. Env (in) decay
8. Voltage Level - Step 3 (in) 22. Level (Gate) 1 in
9. Volatge Level - Step 4 (in) 23. MOD osc waveshaper
10. Voltage Level - Step 5 (in) 24. Keyboard in for mod & complex osc
11. n - sequencer no of steps (in) 25. Level (Gate) 2 in
12. Pulse sequence in. 26. Envelope Det (CV B)
13. Sequencer CV levels (out) 27. Gate Mode 2?
14. Random (trigger) in. 28. Inv (Buffer)
On the vintage easel card, the complex osc has marked a "key" and two "WS" waveshaper inputs.
The modern BEMI easel cards names them "Key", "t.lev" (timbre level), and "tws" (timbre wave shapes - tri/sq/saw).
-------------------------
1. -15V 15. key Volt B
2. ? 16. pulser trig in
3. ? 17. timbre
4. ? 18. attack (envelope)
5. ? 19. Pressure (Env ??? B)
6. ? 20. Envelope Gen (CV B)
7. Voltage Level - Step 2 (in) 21. Seq out (Pulse B)
8. random 22. Mod osc (Mode) in
9. Period in 23. Inv (CV) in
10.index (in) 24. Complex Osc (WS in) 1
11.frequency (in) 25. Complex Osc (WS in) 2
12.Sequencer - *Trig in* 26. Gate Mode 1 ?
13.pitch in 27. SR (Gate out) Offset (EN B)
14.keyboard (pulse B) out 28. SR Gate in (Gate 2 ??)
Modern BEMI cards are 99% the same. They don't have the upper prototyping section
and there is an additional RNG patch point for the mod osc.
The inputs to the "rng" on the BEMI card are 3rd tab, front.
The outputs from the "rng" are tab 27 on the rear of the card (the second last tab).
On the vintage easel card, the complex osc has marked a "key" and two "WS" waveshaper inputs.
The modern BEMI easel cards names them "Key", "t.lev" (timbre level), and "tws" (timbre wave shapes - tri/sq/saw).
-------------------------------------------------------------------------
Amendment. 07 Jan 2018.
Front row, pin 6 is Modulation Oscillator out on the newer BEMI Easels.
Many thanks to Sascha H. of Northern Light Modular for this info.
I haven't checked this on any my easels yet. I have a vintage, a early Roman 208 Rev 2 and a early BEMI.
------------------------------------------------------------------------------
Notes:
++ The trigger point for the sequencer can be either of the bottom two connections
(below the K or P).
It corresponds to Tab 12 on the rear card edge connector.
Looks like the 208 works well with 5V triggers --as tested with my littlebits sequencer.
http://djjondent.blogspot.com.au/2015/12/buchla-easel-vs-korg-littlebits-and.html
++ Muffs- Easel Mega BOB - Cobramatic
++ Muffs 2 - Easel extension card thing
++ Todd Barton - Easel exploration II
--------------------------------------------------------------------------------
If there are any errors, omissions or BS, please let me know.
I'll update this page as I sus out all the connections.
These first 2 pics are for vintage & rev2 versions (not the Rev 1).
1. +15V 15. sequencer (out) B ?? (different to tab13F ??)
2. Gnd (Quiet) 16. Random out
3. ? ("rng" on the BEMI card) 17. Envelope trig in
4. ? 18. Pulser out A
5. ? 19. Env Duration (sustain on the BEMI card) in
6. ? 20. Pulser out B
7. Voltage Level - Step 1 (in) 21. Env (in) decay
8. Voltage Level - Step 3 (in) 22. Level (Gate) 1 in
9. Volatge Level - Step 4 (in) 23. MOD osc waveshaper
10. Voltage Level - Step 5 (in) 24. Keyboard in for mod & complex osc
11. n - sequencer no of steps (in) 25. Level (Gate) 2 in
12. Pulse sequence in. 26. Envelope Det (CV B)
13. Sequencer CV levels (out) 27. Gate Mode 2?
14. Random (trigger) in. 28. Inv (Buffer)
On the vintage easel card, the complex osc has marked a "key" and two "WS" waveshaper inputs.
The modern BEMI easel cards names them "Key", "t.lev" (timbre level), and "tws" (timbre wave shapes - tri/sq/saw).
-------------------------
1. -15V 15. key Volt B
2. ? 16. pulser trig in
3. ? 17. timbre
4. ? 18. attack (envelope)
5. ? 19. Pressure (Env ??? B)
6. ? 20. Envelope Gen (CV B)
7. Voltage Level - Step 2 (in) 21. Seq out (Pulse B)
8. random 22. Mod osc (Mode) in
9. Period in 23. Inv (CV) in
10.index (in) 24. Complex Osc (WS in) 1
11.frequency (in) 25. Complex Osc (WS in) 2
12.Sequencer - *Trig in* 26. Gate Mode 1 ?
13.pitch in 27. SR (Gate out) Offset (EN B)
14.keyboard (pulse B) out 28. SR Gate in (Gate 2 ??)
Modern BEMI cards are 99% the same. They don't have the upper prototyping section
and there is an additional RNG patch point for the mod osc.
The inputs to the "rng" on the BEMI card are 3rd tab, front.
The outputs from the "rng" are tab 27 on the rear of the card (the second last tab).
On the vintage easel card, the complex osc has marked a "key" and two "WS" waveshaper inputs.
The modern BEMI easel cards names them "Key", "t.lev" (timbre level), and "tws" (timbre wave shapes - tri/sq/saw).
-------------------------------------------------------------------------
Amendment. 07 Jan 2018.
Front row, pin 6 is Modulation Oscillator out on the newer BEMI Easels.
Many thanks to Sascha H. of Northern Light Modular for this info.
I haven't checked this on any my easels yet. I have a vintage, a early Roman 208 Rev 2 and a early BEMI.
------------------------------------------------------------------------------
Notes:
++ The trigger point for the sequencer can be either of the bottom two connections
(below the K or P).
It corresponds to Tab 12 on the rear card edge connector.
Looks like the 208 works well with 5V triggers --as tested with my littlebits sequencer.
http://djjondent.blogspot.com.au/2015/12/buchla-easel-vs-korg-littlebits-and.html
++ Muffs- Easel Mega BOB - Cobramatic
++ Muffs 2 - Easel extension card thing
++ Todd Barton - Easel exploration II
--------------------------------------------------------------------------------
If there are any errors, omissions or BS, please let me know.
I'll update this page as I sus out all the connections.
Sunday, 13 December 2015
Buchla easel vs Korg Littlebits (and some patch card magic)
I'm surprised at how good the Korg LittleBits sound through
a Buchla 208.
This setup involves a BEMI easel with the Cobramatic breakout box (BOB) and two of my easel patch cards (the main & satellite).
The satellite one lying on the table with the little bits on top is powered from the vintage easel.
The trigger point for the sequencer can be either of the bottom two connections (below the K or P).
It corresponds to Tab 12 on the rear card edge connector.
Everything is clocked from the Littlebits sequencer even the two easels. We were really surprised how easy this was to do.
Thanks to Adam S for the idea & inspiration to use the LittleBits
This setup involves a BEMI easel with the Cobramatic breakout box (BOB) and two of my easel patch cards (the main & satellite).
The satellite one lying on the table with the little bits on top is powered from the vintage easel.The trigger point for the sequencer can be either of the bottom two connections (below the K or P).
It corresponds to Tab 12 on the rear card edge connector.
Everything is clocked from the Littlebits sequencer even the two easels. We were really surprised how easy this was to do.
Thanks to Adam S for the idea & inspiration to use the LittleBits
Saturday, 5 December 2015
bUCHLA 100 - exploring the 195 filter
I started with the intention of only using one VCO (a 144) and the 195 , ten channel (Octave Format) comb filter to see how many sounds I could get from a minimal setup.
It seems quite a bit.
Over the course of the night I decided to add 3 more VCOs - two 158s & a second 144.
The 285 frequency shifter was used for the sound triggered on key no.1
Signal 158, mod 144. Control mod ... CV from a 281
It seems quite a bit.
Over the course of the night I decided to add 3 more VCOs - two 158s & a second 144.
The 285 frequency shifter was used for the sound triggered on key no.1
Signal 158, mod 144. Control mod ... CV from a 281
Stereosonic 2015 - Sydney Australia
The festival has been marred this year with 2 deaths so far - Sydney & Adelaide.
Please everyone be careful & don't do drugs. The Music is all you need to have a great time.
The final fireworks. !!!
..
Diplo
And what on earth is a "Long Jab Prebuffering module" ?????? I have never seen one of those.
Please everyone be careful & don't do drugs. The Music is all you need to have a great time.
The final fireworks. !!!
..
![]() | ||
| Duke Dumont - one of my highlights. |
Diplo
![]() | |||||||||||||||||||||
| View from the grandstand - Armin van Buuren |
I thought the misspelling of Voltage Controller Oscillator 1 & 2 was funny. Should be Voltage Controlled Oscillator.

Generik
And what on earth is a "Long Jab Prebuffering module" ?????? I have never seen one of those.
Wednesday, 2 December 2015
NLC Collude - build notes
These are my build notes for the Nonlinearcircuits collude module.
It's an envelope follower and very very high gain amplifier (from 2x to 20x).
...... so it should be very useful to amplify all sorts of signals no matter how weak they are
and produce useful voltage envelopes for your modular.
Andrew's build notes are here:
http://www.sdiy.org/pinky/data/COLLUDE%20v1.pdf
There are eight 100k SMDs in the build. I'm using 0805s.
Andrew has given the option of using SMDs or through the hole for the remaining
resistors.
Some NLC wisdom to inspire your build.
Useful links
+ NLC blog
It's an envelope follower and very very high gain amplifier (from 2x to 20x).
...... so it should be very useful to amplify all sorts of signals no matter how weak they are
and produce useful voltage envelopes for your modular.
Andrew's build notes are here:
http://www.sdiy.org/pinky/data/COLLUDE%20v1.pdf
There are eight 100k SMDs in the build. I'm using 0805s.
Andrew has given the option of using SMDs or through the hole for the remaining
resistors.
Some NLC wisdom to inspire your build.
Thank goodness for that!
Datura is a genus of nine species of poisonous vespertine flowering plants belonging to the family Solanaceae.
I'm a bit old fashioned so most of the resistors are through-the-hole. except for the LED resistors.
I'm trying out 470R ones this time. I used 1K in the last project. ... no real method in this... just experimenting.
Surface mount components first, then the IC & power headers.
Thru hole resistors next.
Trannies, Caps, diodes, etc ... all the through hole stuff.
The ceramic cap in the front is 10pf. The schematics ask for a 12pf.
The 4 pots are all 100K linear. I like to insert the pots and jacks on the PCB first without soldering
then screw on the faceplate.
Once you are satisfied that everything is in the correct position , then solder.
Don't forget to solder the ground tabs
Pop those LEDs in and you're done.
I'm a bit old fashioned so most of the resistors are through-the-hole. except for the LED resistors.
I'm trying out 470R ones this time. I used 1K in the last project. ... no real method in this... just experimenting.
Surface mount components first, then the IC & power headers.
Thru hole resistors next.
Trannies, Caps, diodes, etc ... all the through hole stuff.
The ceramic cap in the front is 10pf. The schematics ask for a 12pf.
The 4 pots are all 100K linear. I like to insert the pots and jacks on the PCB first without soldering
then screw on the faceplate.
Once you are satisfied that everything is in the correct position , then solder.
Don't forget to solder the ground tabs
Pop those LEDs in and you're done.
Useful links
+ NLC blog
-----------------------------------------------------------------------------------
You can find more NLC builds here.
---------------------------------------------------------------------------------------
Tuesday, 24 November 2015
NLC - 2 x LFOs - Build notes
These are my build notes for the NonLinearCircuits Dual LFO & difference rectifier (Eurorack version).
It's a easy build as all parts are through the hole.
Andrews build notes are here:
http://www.sdiy.org/pinky/data/WAMOD10%20dual%20LFO.pdf
and his blog notes are here:
http://nonlinearcircuits.blogspot.com.au/2015/03/dual-lfo-with-difference-rectifier.html
Some pics of the virgin PCBs
And the rear.
There are two op-amps used : a TL074 & a TL072
.
Headers first.
Resistors next.
This LFO uses a combination of integrator & schmitt trigger. It's quite a commonly used combo.
This is a simplified version of Andrew's circuit.
The op-amps "A" & "B" are part of the TL 074. "A" is the non inverting schmitt trigger. "B" is the integrator.
The output of the Schmitt trigger is a square wave. This is fed into the integrator. The output of the integrator is a triangular wave, which is fed back to the Schmitt trigger. Thus first stage drives the second, and the second drives the first..... which came first ???? the chicken or the egg ???
The last part of the module is a diference rectifier which is described by Andrew thus:
"This circuit is a hybrid of two basic op amp ‘building blocks’ .....a difference circuit and a rectifier.
It takes the triangle waves (from the 2 LFOs) and supplies a signal that is the difference between them"
http://www.sdiy.org/pinky/data/dif.html
The NLC module uses two standard 1n4148 signal diodes for this rectifier circuit.
"Basically the circuit compares the voltage on the ‘-‘ inputs with the voltages on the ‘+’ inputs. (on the 072 op-amp). The difference between these voltages is fed to the outputs. If the difference is positive it appears on the ‘+’ output, if the difference is negative it appears on the ‘-‘ output. Again, a great way to mix boring CVs to get something interesting, audio frequency wave - shaping. "
The two electro caps I'm using are rated 25V.
I've used monolithic ceramic capacitors for the two 1uF 105s.
The three 100nF 104s are straight ceramics
I've used 1k 0805 SMDs for the LED resistors. Not really sure of the exact value but they are easy to change if needed.
As it turned out, the 1K resistors seem to work well.
The pots now. I was debating whether to chose two audio 100k pots (for frequency adjustment) and two linear pots for the fine adjustments, but Andrew advised me to use all linear100K pots
Useful links.
+ Video - VCO using a Schmitt trigger & integrator.
+ Pdx.edu VCO
+ Falstad.com
+ Thomas Henry - The birth of a synth
+ The two amp oscillator
+ Circuits Today
+ What is a schmitt trigger and how it works
+ NLC build notes for the difference rectifier & neuron
---------------------------------------------------------------------------------------------------
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html
It's a easy build as all parts are through the hole.
Andrews build notes are here:
http://www.sdiy.org/pinky/data/WAMOD10%20dual%20LFO.pdf
and his blog notes are here:
http://nonlinearcircuits.blogspot.com.au/2015/03/dual-lfo-with-difference-rectifier.html
Some pics of the virgin PCBs
And the rear.
There are two op-amps used : a TL074 & a TL072
.
Headers first.
Resistors next.
This LFO uses a combination of integrator & schmitt trigger. It's quite a commonly used combo.
This is a simplified version of Andrew's circuit.
The op-amps "A" & "B" are part of the TL 074. "A" is the non inverting schmitt trigger. "B" is the integrator.
The output of the Schmitt trigger is a square wave. This is fed into the integrator. The output of the integrator is a triangular wave, which is fed back to the Schmitt trigger. Thus first stage drives the second, and the second drives the first..... which came first ???? the chicken or the egg ???
The last part of the module is a diference rectifier which is described by Andrew thus:
"This circuit is a hybrid of two basic op amp ‘building blocks’ .....a difference circuit and a rectifier.
It takes the triangle waves (from the 2 LFOs) and supplies a signal that is the difference between them"
http://www.sdiy.org/pinky/data/dif.html
The NLC module uses two standard 1n4148 signal diodes for this rectifier circuit.
"Basically the circuit compares the voltage on the ‘-‘ inputs with the voltages on the ‘+’ inputs. (on the 072 op-amp). The difference between these voltages is fed to the outputs. If the difference is positive it appears on the ‘+’ output, if the difference is negative it appears on the ‘-‘ output. Again, a great way to mix boring CVs to get something interesting, audio frequency wave - shaping. "
The two electro caps I'm using are rated 25V.
I've used monolithic ceramic capacitors for the two 1uF 105s.
The three 100nF 104s are straight ceramics
I've used 1k 0805 SMDs for the LED resistors. Not really sure of the exact value but they are easy to change if needed.
As it turned out, the 1K resistors seem to work well.
The pots now. I was debating whether to chose two audio 100k pots (for frequency adjustment) and two linear pots for the fine adjustments, but Andrew advised me to use all linear100K pots
I've used scrap resistor wire for the ground connectors
Testing the square & triangle waves.
Lovely !!!
Useful links.
+ Video - VCO using a Schmitt trigger & integrator.
+ Pdx.edu VCO
+ Falstad.com
+ Thomas Henry - The birth of a synth
+ The two amp oscillator
+ Circuits Today
+ What is a schmitt trigger and how it works
+ NLC build notes for the difference rectifier & neuron
---------------------------------------------------------------------------------------------------
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html
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