Tuesday, 26 March 2019

Buffered Multiple with LED indicator

Multiples aren't the sexiest thing to build but they are essential in any system.
Really easy to build.
The choice is between buffered and un-buffered.

Building a buffered one today.

Here is the breadboarded test circuit.

The basic schematic

The opamp can be a TL084 or TL074
The pinout is identical for both ICs

This particular circuit uses a 074

One change I decided to make was to add a LED to give some sort of indication as to the type of signal this multiple was carrying.
Inspired a bit by the makenoise CV bus

To quote the manual:
"The CV Bus was originally designed for Alessandro Cortini's personal Make Noise system. It provides visual indication of level, rate and polarity for up to 4 control signals that will be shared throughout a patch. ..."
The MN CV bus is I understand passive/unbuffered & those jacks have LEDs built into them.

Here is my 1st perfboard 2HP module.

And the rear
I used a 1K LED resistor. ... experiment a bit.
This LED is standard so will only indicate rate & level.
I'll need to use a bipolar LED to get an indication of polarity.

It works !

I'll build a few versions with different coloured LEDs and try some bipolar ones too.

Bipolar LEDs work well.
(cATHODE  to ground)
Use a 470R resistor for green-red LEDs

Sunday, 24 March 2019

Modular in the Lounge Room VI

Yah... Modular in the Lounge Room 6 is here.
Sat 23rd March 2019.

Thanks to Terry for the great visuals.

Ilya with some lazers

More pics to come.


aNDREW aka Virus Installer

Paul - aka Allinaire

Mitch- aka Vitals




Past Modular on the Lounge gigs:
+ Modular in the Lounge V
+ Modular in the lounge IV
+ Modular in the lounge III
+ Modular in the lounge II
+ Modular in the lounge I
+ Modular in the Car Park

Buchla Synth Timeline

A brief timeline of the Buchla Synthesizer

1937 ------------------- Don Buchla born in Southgate California

1959 ------------ Don Buchla received a degree in physics (University of California, Berkeley)

1962 ------------------Don became involved with the San Francisco Tape Music Center

1964 ------------------------ design of the 100 series Modular Electronic Music System started

1965 ----------------- The first 100 series is delivered to the SFTMC
                          (San Francisco Tape Music Center). The SFTMC eventually became
                          Mills College.

1967 --------------------- "Silver Apples Of The Moon"  released (Morton Subotnick)

1968/69 ----------- the Series 100 was sold to CBS Musical Instruments

1969 ------------------- Buffy Sainte Marie's album, Illuminations 

1970 -------------------------------------------  the 200 series Electric Music Box

1971 ------------------ 237/238  keyboard created (the first polyphonic modular controller keyboard)

1972 ------------- the 500 series, hybrid digitally controlled analog synthesizer announced.
                               It was designed over previous years.

1973 ------------------------- Buchla Music Easel

1976 ----------- the Series 300 (Don combined the Series 200 with microprocessors).
                    This was actually started in the Autumn of 1975, but 76 was when the
                    work was really done. 
1978-1980 ------------------------------------------------ Touché

1978/9 -----------------  Sili-Con Cello (This was a performance based piece, not a product).

1982 ------------------------ Buchla 400

1986 ---------------------------------------------- the Buchla 700 with MIDI

1989 ---------------------------------------------------- Thunder controller

1991 --------------------------------------- Lightning controller

1995 ------------------ Oberheim OB-Mx

1996 ------------------------------------------------- Lightning II controller

1999 -------------------------  Marimba Lumina (gold edition)

2000 --------------------------------------------------- Marimba Lumina 3.5 (silver)

2002 ---------------------------- Marimba Lumina 2.5

2002 ------------------------------------- Piano Bar (Manufactured by Moog)

2002 ------------------------------------------- Barber Pole modules released.

2004 ---------------------- 200e series

2012 ------------------------------- BEMI formed

2013 ------------------------------------------- BEMI re-introduced the Music Easel.

2014 ------------------------ Don is forced out by BEMI

2014/5 ---------------------------------------------- 252e

2016 -------------------- Don Buchla passes at the age of 79 on September 14.

2017 ----------------------------------- BEMI released the Easel AUX Expander

2018 --------------- Buchla USA formed - BEMI takes on a partner & rebrands as Buchla USA


Buchla 100 series

This synth was commissioned by Morton Subotnick and Ramon Sender in 1963 and funded by a $500 grant from the Rockefeller Foundation. The earliest modules have no company name on the front panel, or are labeled "San Francisco Tape Music Center." The 100 series company was sold to CBS in 1969. These later modules are labelled CBS musical instruments.

The original instrument was installed at the San Francisco Tape Music Center in 1965 and moved to Mills College in 1966.

Buchla 200 series

The Buchla 200 series Electric Music Box replaced the 100 series in 1970. This was a huge advance in technology with greater use of CVs (control voltages)

Buchla 500 series

The first hybrid synthesizer. A computer was now added to to a analog synthesizer aid the process of
music creation

Buchla 300 series (1976)

This system employed digitally controlled 200 modules.
It included a computer 
It's a Digital/Analogue Hybrid Music system . It used Patch IV software for routing control signals and inputting program data. The software was initially developed for 8080 & Z80 based machines

Touche (1978 - 1980)

Used a traditional 61 note keyboard. It was a hybrid digital computer married with analog circuitry.
8 voice polyphonic synth with 3 oscillators per voice.
It was controlled using a computer running FOIL (Far Out Instrument Language).
Apparently only four of these were ever made

400 Series (1982)

No patch chords!
6 voices of Digital oscillators.
Uses the MIDAS computer language to program the oscillators, filters, amps etc
Designed for film scoring ?

700 series (1987)

The first MIDI Buchla device. It also had CV/Gate, SMPTE, and two RS232 ports.
Almost all the controls are touch plate (apart from 5 pots).
12 voices with 4 digital oscillators per voice.... that's 48 oscillators
 6 modifiers per voice.
15 envelopes per voice. Each envelope can have up to 96 breakpoints.
It ran MIDAS VII software

Thunder (1989)

The first assignable MIDI controller based on ergonomics.
The human hand placement was foremost in its design.
Nothing like a standard keyboard.

Lightning 1991

It has two wands or sticks that are sensed by the main unit.

Marimba Lunina 1999

The mallets have radio transmitters in them.


++++ the dates and info are as accurate as I can find ++++
++++ If there are any mistakes or omissions please shoot me and email +++++

Saturday, 23 March 2019

Dave Smith Instruments - OB-6 - mucking around

Some mucking aroung with a OB-6 a friend brought over yesterday.
 Just playing with the presets.

A post shared by jono (@dj_jondent) on
Lovely instrument.
Thanks Gareth and oscillosaurus

Wogglebug comparisons

The wogglebug is a great source of random voltage. Essential for all my patches.
It was inspired by the buchla 265
These 265s are very rare. I love the name ... the source of uncertainity.

Grant Richter of Wiard Synthesizers took inspiration from the "smooth" and "stepped" fluctuating random voltage sources that you can see on the 265 and came up with the wogglebug.
He expanded on this theme expanding it to such things as Woggle CVs (stepped voltages with decaying sinusoids edges).

There are many flavours of bug.

My first was the buchla version you can see on the right:

On the left is the Erica synths version in Eurorack format.
They are all slightly different.

The most common versions are from MakeNoise:

 No comparison would be complete without the orginals:


Friday, 22 March 2019

Soma Dvina as a Eurorack controller

 A video on how the Soma Dvina can be used as a Eurorack controller.

For more info and how to get GUI2LAR please send a letter to etera.sound@gmail.com
GUI2LAR is in development but you can get in the preorders list and be among the first owners.

Thursday, 14 March 2019

NLC GENiE - build notes

These are my build notes for the Genie Eurorack module.
Its from nonlinear circuits in Western Australia.

+ NLC Blog
+ NLC Wiki
+ BOM & build guide
The name is from the computerdescribed in the 1964 Keith Laumer novelThe Great Time Machine Hoax, although this module differs in ability (can’t time travel or get married ..... afaik), the name is quite suitable

Friday, 8 March 2019

mENG Qi - Dual Passive Low Pass Gate

I've been looking for some Buchla inspired LPG modules lately for my performance case and came across one by Meng Qi.

There were no build notes with this but its pretty simple so was easy to figure out.
Resistors: 390R x 2
Diodes: 1N4141 x 1
Capacitor:  1500pF or 1.5nF (152)
Misc: Vactrol, jacks, panel, pcb, LED

These are not official build notes... just my record keeping in case of future trouble shooting.
 Make sure you get the LED orientation right.

So what exactly is a low pass gate?
The term was first used by Don Buchla and was used in the 200 series 292 module.
It can behave as a VCA, a low pass filter, or a combination of both.
The Buchla design used a vactrol to process the control voltage input. The choice of a vactrol was a stroke of genius as it introduced non-linearities which made the lowpass gate a good module for making percussion sounds like hand drums, bongos,congas & steel drums.

I'm not sure what vactrols are used in the version as the labeling appears to be blocked out.
So this shall remain a mystery. Don used VTL5s . You could also make your own using a LDR and a LED.
The NLC Dual LPG is a good example of how to do this.

The module is only 2HP width.
The gates are I think 6dB slope ... that is single pole/

What surprises me about this module is just how good it sounds ........and all without any power .
A single trigger pulse is all you need 

Orientation of vactrol ... match the dots.

a REALLY simple build ... great as a starter SMD project.

Useful Links:
1. CGS/Elby - Ken Stone's LPG
2. Buchla Tech - Verbos's excellent blog - 292c Secrets with schematics
3. Synth.NL.Blog - 292 5U build notes
4. Modular Synthesis - Build notes for Thomas White's LPG clone.
5. Doepfer A-101-2 LPG filter
6. Natural Rhythm Music - Thomas White
7. NLC Dual LPG

Monday, 4 March 2019

NLC Spasm

The SPASM is a LDR controlled jerk chaos module in Eurorack format.
This is a DIY build.

This module takes the classic Sprott jerk circuit and replaces all the resistors with LDRs.....a 7 way vactrol. 

This means the brightness of the LED in the giant vactrol controls the frequency of the circuit.

What exactly is a JERK circuit..??

"Jerk equations were developed by JC Sprott, .... (they) are very simple equations that are easily implemented as circuits, the diode is the nonlinear element, which is cheap and easy to get. Many chaos circuits use multipliers like the AD633 ($15 each), so I like to avoid those". (Andrew F).
The intro of this paper is a good explanation - http://sprott.physics.wisc.edu/pubs/paper229.pdf

Op amps first.

RL LED resistor ... using a 0805 resistor for panel LED... I'm using a 10K.
RLBox .. using a 2.2k 

I'm using GL5549 LDRs...I have a bag of 100's of these suckers.
These LDRs can go up to 10M+ (In fact they range anywhere from 10MΩ to 20MΩ), so they will be a lot slower but should give a much wider frequency range and some very unpredictable outputs.

I'm going to use 1uF caps with this so as not to go too slow. The great thing about SMD caps is that they are so easy to change. Andrew F says that 10uF will make this extremely slow, and 100nF very fast

 Building the vactrol box

 Line everything up & then solder
Only using double headers as i didn't have any singles on hand.

Feedback pot. "If building a very slow version, a 1M pot is better but not essential". (AF)
I'm using a A500k pot
There is a single LED in the Vactrol surrounded by 7 LDRs

Get the LED orientation right.

The LED section of the vactrol schemo.
 The anode goes to ground

More links to NLC (nonlinearcircuits) projects.

+NLC Blog 
+NLC Wiki
+Build guide & BOM 
+ Sprott's Gateway 
+Wolfram - Demos