Monday, 30 March 2020

Making the Lyra panel

I've had lots of emails asking how I made the panels for the Lyra Synth.
These weren't made by me.
However, you can make them yourself.The .brd files are here:

A BRD file is a CAD file created by EAGLE
The faceplate is actually a PCB.
Here is what the file looks like when opened in EAGLE
 You can also import designs from Eagle into Altium, EasyEDA or KiCad

 The pic above is using KiCAD
 oNCE you have imported these files into your CAD program of choice, you will need to export them as Gerber files.

Using KiCAD as an example:
select File - 
select Plot

 Select Generate Drill files

You need to compress the final files into one zipped folder.

The files can now be sent to your PCB manufacturer.
I'll use JLCPCB as an example.
Use the quote now button

Upload the zipped file then
Check in the Gerber Viewer.

You are just about there.
Tweak colour, etc for your personal taste.

Let me know is there are any mistakes, errors or omissions.
Cheers J

 + Lyra 8 build - part 1 
 + Lyra 8 Part 2
 + Lyra 8 Part 3 is here
 + Making the Lyra Panel face plate

Saturday, 21 March 2020

ARP index

This is my blog index for all things ARP
I'll try to keep this updated.
You can always find the link to this page on the right of the blog home page.. Under "Blog Index"

ARP 2500

+ Sync the ARP 2500
+ ARP 2500 - modular jamming 070919
+ Oscillator Cores & Exponential Converters
+ RIP Alan R. Pearlman
+ Moog Mother Drums
+ 1050 Mixer sequencer - Build notes
+ 3Trins RGB + 1c
+ NLC 1006 filter 
+ ARP 2500 - My Monday Fix
+ ARP 2500 - Modcan'd
+ Arp Sat arvo jam
+ ARP 2500 - My Resonator Addiction
+ arp 2500 - VCO 1023 Module tests
+ ARP 2500 Patch sheets
+ ARP 2500 - Filter bubbles
+ arp 2500 - SOME LIVE TWEAKING of the 1045
+ ARP 2500 - Module 1045 - Voltage Controlled Voice
+ ARP 2500 - Vintage Brochure
+ ARP 2500 DIY cabinet
+ ARP 2500 sales brochure from 1971.
+ Scanimate Matrix Switch Panels
+ ARP 2500 - The Speed of Life
+ ARP 2500 & NLC 
+ Tokyo Modular Synth Festival 2015
+ ARP 2500 - Future Deep House
+ ARP 2500 - Sample & Hold (videos 1 and 2)
+ ARP 2500 - SAMPLE & HOLD / RANDOM VOLTAGE (1036 module)
+ The ARP 2500 & the 1005 MODAMP module
+ ARP 2500 - Envelope Generators
+ ARPParty
+ ARP 2500 - Patch 3
+ ARP 2500 - Patch No 2 
+ ARP 2500 - first patch
+ Arp 2500 sequenced by a Roland TB 303

ARP 2600

+ Acidic ARP 2600 
+ ARP's 2600 & Arturia's MicroBrute - party !! 
+ ARP 2600 - groove sequence
+ ARPParty


+ TTSH - ARP 2600 - Build notes - Index
+ TTSH - Arp clone - first impressions (video)
+ Building the TTSH - A 14 minute Video Diary

General Misc

+ Synthesizer shopping in Tokyo
+ Eurorack NLC 1050 Mixer sequencer - Build notes
+ NLC Serious Filter - ARP Odyssey 4023
+ NLC 1006 filter
+ The αρπ Filter (alpha-rho-pi) with a kilpatrick Phenol
+ ARPParty 
+ ARP Modular Synthesizer Lab (MSL)
+ The Ship of Thesus

Sync the ARP 2500

Syncing the ARP 2500.
Master or slave?

 ARP as the master .
It sends a 8V clock.
The 1027 sequencer also outputs 10V pulses from the "position gates"
As a master its easy. esp with a modular synth like the TTSH or a 2600
This also works quite well with my eurorack.

Use the clock out.
It's a 8V pulse per step.

ARP as a slave.
I'm again using the ARPs clocked sequential module ... the 1027 .
It's a 10 position sequencer.

The step input.
Electrical specs:
According to the manual, the perfect input for step, repeat, on & off is +8.0V.
The 1027 sequencer however, outputs 10V pulses from the "position gates"
and the manual suggests connection the "s" input to the "position gates" ... so I think 10V pulses should be safe to use.

Another way to sequence the sequencer is via the "VC frequency".
... this controls the clock frequency

I've found 3 methods that work.
The first two use a clock signal that triggers the step input on the 2500.
So the ARP 2500 is the slave.

The first uses a Kenton  Pro solo Mark 2
I used a Deluge as the master Midi module ... sending midi clock to the Pro solo.

The settings are as follows:
This also works for Buchla.

 Method 2 
Elektron Analog Keys.
The A4 should work the same.
Go into your global settings and set CV C or CV D to Clock.
If you only have a standard mono cable use CV C as this sends the clock to the tip.
(CV D sends it to the ring)

tHE length of the pluse can vary. My 2500 responds well to 24ms length, but its also ok up to 32.
8V pulses work fine. Probably 10V will be ok ??

Set the clock control to trigger.

tHE third method was using a roland SH 101

tHE "gate out" voltages are perfect.

Friday, 20 March 2020


 These are  my build notes for the nonlinearcircuits Dual LFO/VCO module.
Its Eurorack format.

 These are the virgin PCBs

icS first

I'm waiting on some parts.
The LM13700 is a general purpose op-amp.

The DG202 is a CMOS switch. Its a quad SPST switch.
The DG 212 should also be ok to use.

The "DG " stands for double gate.
Double Gate CMOS  (DG)
 Traditional CMOS technology is approaching physicial limitations was we approach the nanoscale regime.
One such solution is the double gate transistor, proposed in the 1980s.
"Multigate transistors are one of the several strategies being developed by CMOS semiconductor manufacturers to create ever-smaller microprocessors and memory cells, colloquially referred to as extending Moore's law."

If you don’t really care about 1V/oct tracking then you do not need
to install 1k tempcos but you must install the 1k 0805 resistors on the bottom side of the PCB.

the 3mm LEDs are bipolar. They are 2 pin.
If red/green use 1k for RL. If red/blue use 4k7 for RL 
I'm using red/green LEDs

to be continued...............
Part 2 is here:
NLC Dual LFO/VCO - part 2


+ NLC Wiki
+ NLC Build guide and BOM
+ NLC Blog (old)
+ NLC blog (new)
+ CMOS  info 
+ NLC DIY info

---------------------------------------------------------------------------------------------------   Click here to return to the NLC Build Index: 

The algorave movement

What is this?
It's a combination of 2 words .... Algorithm & Rave.

"An algorave is an event where people dance to music generated from algorithms, often using live coding techniques.Algoraves can include a range of styles, including a complex form of minimal techno, and the movement has been described as a meeting point of hacker philosophy, geek culture, and clubbing.

Although algorave musicians have been compared with DJs, they are in fact live musicians or improvisers, creating music live, usually by writing or modifying code, rather than mixing recorded music."

Basically, artists code live on computers.
The code produces music and controls visuals.
The visuals usually include the code itself, so the audience can see the music as it evolves and is written.
The software is free & opensource. Much of it will run on really basic computers (eg a raspberry pi ) making this form of music easily accessible to everyone.

Their logo is a Spirangle.
It's a cross between a triangle & a spiral.

Currently, there is live performance of artists coding and performing all around the world.
It's taking place today,  March 20.
This is also known as the March Equinox ... actually it occured a 2.49pm in Australia.
This marks the arrival of Spring in the Northern Hemisphere & Autumn in the Southern.

The coding festival is called Eulerroom Equinox

They also have a facebook page

Check out my page on Sonic Pi
It's a great tool to get you stared on coding.

TidalCycles is also a great resource for music coding.
 as is Gibber

Hydra is a good place to start learning to code visuals

Thursday, 19 March 2020

OPTIGAN ios app

Get this while its free
(only 1 week)

You can download it from the Apple app store

It's an optical organ ... or a chord organ from the 1970s.
It was sold by Mattel.
Author PMDrive1061

Very lo-fi, but I like it.
Used optical discs to sample prerecorded music.

This reminds me of the Soviet ANS synthesizer

Cool samples

Other synths on the same lines that uses optical discs are the Panoptigon from Quilter Labs.


The Vako Orchestron
Kraftwerk made heavy use of the Orchestron on their albums Radio-Activity (1975), Trans Europe Express (1977) and The Man-Machine (1978). 

There were only about 70 to 100 Orchestron's made

Wednesday, 18 March 2020

NLC Shat Noir - build - part 2

This is part 2 of my Shat Noir build.
It's a Eurorack format module.
Part 1 is here:

Sorry for the delays in finishing the module.

The trimpots

Start building the vactrol box

uSING  strip headers

with LEDs, usually this holds:
The square pad represents POSITIVE
The round pad represents NEGATIVE
Anode - positive, long lead
Cathode - flat side, short lead

 The light dependent resistors

Tayda: A 1851 --- linear B 100K


The CV drive is an anti-log circuit, it works a little differently as
both the CV and phase pots must be adjusted to find the sweet spots. 

If one of these pots is at zero, the other will not have any effect.
The In2 pot is 0 at centre, the incoming signal is inverted below that.
it is intended as a feedback input for one of the stage outputs, but
shove in whatever you want of course.

There are 2 trimpots .. feedback & range

"The 1M feedback trimpot pot should be set so the circuit just starts to scream when the panel pot is at max. This can vary a lot depending upon the signal source and its frequency.
Best to leave it in the middle to start and adjust if your module is too squeaky.
The 1M range trimpot sets the operating range for the CV and Phase panel
pots. Again leave it in the middle to start and adjust if you find the
panel pot operating range is t
oo narrow or wide. You may need to adjust
the 470k* resistor sitting next to the trimpot as well. Generally it is
happy about in the middle".

+ NLC Blog
+ Wiki


Click here to return to the NLC Build Index: 

Saturday, 14 March 2020

Happy Pi day

Happy Pi day

3.142  ...

Pi is approximately equal to 3.14159.
Take this opportunity to download Sonic Pi.

It's free.
It's a great way to learn programming that is linked to electronic music

An example - Daft Punk


Thanks Sam Aaron

Thursday, 12 March 2020