Showing posts with label Eurorack. Show all posts
Showing posts with label Eurorack. Show all posts

Wednesday, 24 January 2018

USB connections

 THere are lots of different types of USB connectors and jacks.
In the synth world they are used for a wide variety of applications ... from simple power to data transfer

The jacks can be confusing
 
These were the first types
 


B is commonly called a printer USB cable.
A is still the most widely used type of jack. 
 
USB-B micro is commonly found on lots of synths made in the past 5 years 
though it seems to be fading out of popularity in favor of type C
 
 
 
 
 
 
 
 
 
 
 
 
 

 This Expert Sleepers FH-1 is a midi host
It uses a Type-A USB connector for MIDI
















This is a 2HP midi module

It uses a USB-B micro socket
The Roland JUo6A boutique synth also uses a USB port: MicroB type for Audio, MIDI.
Older android mobile phones like my Samsung galaxy note 5 used this connector.

 
 THis has the advantage that you can plug your cable any orientation.
Most android mobile phones like my Samsung Galaxy 9 use this type of connector.








Many of these connectors supply power to your module.
It's handy to know what is what

The first two connectors (A + B) had just
four connections.
 
1 = +5V
2 = Data -
3 = Data +
4 = GND

The Mini & Micro cables added a 5th connector called
"ID". This helped distinguish cable ends.

 
 
 
 
So for the Mini/Micro USB A & B
 
1 = +5V
2 = Data -
3 = Data +
4 = ID
5 = GND 


This is the Teenage Enginering OP-z
It uses the Type-C connector

The OP-1 used type B-micro




Wednesday, 17 January 2018

Modular Eurorack Compressor

 There are plenty of off the shelf compressors you can buy.
However by building one yourself, you'll learn the principles of how they work.

You can actually build a compressor with a envelope follower, a an inverter and a VCA. 
A modular compressor is essentially a voltage controlled envelope follower tied to a VCA.
 
The 4 basic components:
1. Mult
2. VCA (linear preferably but a exp VCA will work too)
3. Inverter / attenuverter
4. envelope follower
 
 
 First split the signal into two.
a. the original signal (A) to be compressed.
b. the side chain detector signal (B)
 
Signal A --> envelope follower ----> inverter ------> CV input of VCA
Signal B --------> audio input of VCA
 
The fun thing about building your own compressor is varying the components.
The VCA for example could be vactrol based LPGs 

You could use a Make Noise Maths. It could perform the envelope follower & voltage inverter tasks.
A serge DUSG could do this as well, as could the Doepfer VCS( A-171-2). 
 
This is a patch for compressing a bass drum
In this example channel 4 is acting like a slew limiter.
It's output is plugged into the input of channel 3. It's in inverter mode.... creating an inverted
version of channel 4. 
Chanel 2 of the maths is simply amplifying the straight audio of the bass drum.
It's then going into the second audio input of the VCA.
I'm using the HP filter to remove some of the lower frequencies. I could also use an EQ.
 
 I've swapped the LP filter for a delay in the above example.
The delay has lots of CV inputs which could be modulated with LFOs, the Maths, sequencers, or EGs. 
The Doepfer A-119 envelope follower has a voltage comparator with a gate output that can be used to trigger envelopes.
 
Of course the signal processed in the VCA doesn't have to be the same signal that is being analysed by the envelope follower. The open architecture of a modular synthesizer allows you to design any kind of side-chain compression scenario your heart desires.  


Another interesting module is the Bastl Dynamo.
Its just 5HP and contains two Envelope Followers with inverted and non-inverted 
Envelope Follower Output. There is also a Compressor CV Output with indication LED 
(only negative voltage when envelope is greater than the threshold.
When the Compressor CV is plugged into CV input of a VCA with offset and attenuator knobs you get an Compressor!
 
 
Extra modules that would come in handy
5. mixer
6. Slew Limiter
7. EQ
8. filters
9. comparator
 





 Links
 


Tuesday, 19 December 2017

Master Clock & utilities Eurorack case

 Utilities are pretty boring, but necessary.
Over the years Ive struggled to find ways to clock everything that I have.
Is it possible that one device can to it all ???
Probably not, but you can build a case with the modules to do it all.
I think I finally have it.
 
 
The trigger, drum modules and compressor arent necessary, but they are useful to have and certainly do 
make the case even more handy.
 
The main clock source is the cyclic slew 1U. 


The Synthrotec CVGT1 does all the Buchla / Euro conversions. 
Both control voltages, triggers and gates.
 
We need a clock divider/multiplier (2hp), a CV sequencer (Pico).
The mutant brain allows me to trigger drums with MIDI 

The Disting is a mark 1. Its enough.
 
 
 
 
 
 
 
 
 
 
 
 
I can clock my ARP 2500 easily with a gate from the Synthrotec.
 
The CVGT1 has a silver ground jack. (banana).
 
I needed to make a conversion cable -- on one end is the 6.5 mm jack which plugs into the clock input of the ARP sequencer.
 
The other end of the cable has two ends...  a banana ground jack & a banana tip jack.
 
These plug into your CVGT1 ground & gate outputs

Works flawlessly
 
 

You can also clock old Moog, Korg & Yamaha gear which needs V-Trig to S-trig conversion.
You need to make a cable for this,

 
 
 















Some more pics


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Links

Saturday, 2 December 2017

DIY index

This is the index for all DIY projects.

General Electronics
+ LCD display i2c - part 1  
+ LFOs - making simple LFOs using a CD 40106 IC
+ Microcontroller... What you need to program a MCU 
+ Microcontrollers... Programmers
+ Sequencer CD 4017 
 + Simple oscillators & LFOs using a CD 40106 IC
+ OTAs - operational transconductance amplifiers
Panel, making using gerber files
+ Switches - Momentary push buttons & Pull down resistors   
+ TKB - Serge Build notes (Human Comparator)

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

+ 3 Trins Video synth
+ The Ship of Thesus
+ Adding anchor links in Google blog

ARP 2600 - TTSH

Balanced vs Unbalanced Audio

Buchla
 
Cat Full Of Ghosts
 


Ciat Lonbarde
 + Gerassic Organ

CMOS
+ Sequencer CD 4017 
+ Simple oscillators & LFOs using a CD 40106 IC

Eurorack

 + Adding +5V  to your Bus.
 + Distribution  - power bus

Elmyra Synth 
   + Build notes


Fates 
+ Fates - a DIY Norms for Rasberry Pi

 Influential ICs

Jasper - Wasp
+ Build notes for the jasper - Part 1
+ Jasper build notes - Part 2
+ Midi interface

Lorre Mill
  + U Tone

LZX - Cadet
 + Cadet I - Video Sync Generator - Build notes
 + Cadet II - RGB Encoder - Build notes
 + Cadet III - Video input - build notes
 + Cadet IV - Dual Ramp generator - build notes
 + Cadet V - Scaler - build notes
 + Cadet VI - Fader - Build notes
 + Cadet VII - Processor -Build notes
 + Cadet VIII - Hard Key Generator - build notes
 + Cadet IX - VCO - build notes
 + Cadet X - Multiplier - Build notes

LZX - Castle
Introduction
00_000 ADC - Analog to digital converter
01_001 DAC - Digital to Analog converter
02_010 Clock VCO
03_011 Shift Register
04_100 Multi Gate
05_101 Quad Gate
06_110 Counter
07_111 Flip flops


Microcontrollers
+ Microcontroller Index Page

NLC
Full list of (NLC) NonlinearCircuits projects

PSU  juice for your synths
 + NLC large board - build notes
 + NLC small board - build notes  
 + BOSS ACA vs PSA Psu (Power supplies)


+ Resistor Arrays
+ Serge - CGS - Buchla

+ Shopping for components
+ Soma - Lyra 8 build
+ Synth Lab (SDIY)
+ Synthacon - Steiner-parker

Python
+ Python for beginners 1
+ Python for Beginners 2

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

Thermin
+ Thermin - Silicon Chip general info

Vidiffektor - build notes

Wirehead Freaq FM

Wasp - Jasper
+ Build notes for the jasper - Part 1
+ Jasper build notes - Part 2

-----------------
+List of integrated circuit dimensions
+Surface Mount Nomenclature & Packaging.
+SOT (Small Outline Transistor dimensions)
+Voltage divider, LED resistor calculator 
+SMD / SMT resistor code
+Desoldering tips - Belltone 

 

 "The man that hath no music in himself,
Nor is not mov'd with concord of sweet sounds,
Is fit for treasons, stratagems, and spoils."
- The Merchant of Venice (V, i, 83-85)

 

Modular On The Lounge

The first MOTL (Modular On The Lounge) .... held at a secret location in Wollongong, NSW, Australia.

All my synth friends were dying for a chance to get together, chat about synths, and get some performance practice.
 So we found a living room and couched it for the night.

 A great turnout.
 
 We set up a projector and a Video Synth.

Justin from Metro Modular showed us some of his new modules.

This modular just arrived back from Japan.


The MM339A Gainriding VCF
I'm especially looking forward to this filter as it's original designer was Dennis Colins who had a hand in designing the ARP 1047 filter (for the ARP system 2500).

MM6031B Marshall LPF Explorer Edition


Hopefully there will be more of these nights in the future.

A post shared by jono (@dj_jondent) on

 #cobramatic

A post shared by jono (@dj_jondent) on

Thursday, 30 November 2017

CellF Action - Build notes

Finally getting around to this.
Andrew put these out in 2015 (along with the CellF Voice).
Andrew's build notes are here:
http://www.sdiy.org/pinky/data/cellF%20action%20BOM%20&%20build.pdf

A big-ish build I think.

Some closeups of the PCB to help with later troubleshooting.
Right of PCB

Centre PCB

Left PCB

The Action panel uses three NJM13700
https://www.njr.com/semicon/PDF/NJM13600_NJM13700_E.pdf
They are current controlled transconductance amplifiers.
I'm using the same components I used on the cluster build


ICs:
I'm using sizes SOIC-14/16, SOP-16
SOIC = Small Outline IC
SOP = Small Outline Package 

"A Small Outline Integrated Circuit (SOIC) is a surface-mounted integrated circuit (IC) package which occupies an area about 30 to 50 % less than an equivalent dual in-line package (DIP), with a typical thickness that is 70 % less. They are generally available in the same pin-outs as their counterpart DIP ICs. The convention for naming the package is SOIC or SO followed by the number of pins. For example, a 14-pin 4011 would be housed in an SOIC-14 or SO-14 package."
(Wikipedia)
 There are 5 fixes needed to the slew of the logic module.
 

 I added the 47K resistor to the underside of the PCB

gETTING there. Just waiting on some components from Mouser.
This is a big build.
ICs and most of the SMD passives are in.


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

Having trouble sourcing the TLP291-4 - quad opto-coupler package. ?? Mouser no
I'm trying these:
https://au.rs-online.com/web/p/optocouplers/6936807/

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LED resistors.
I'm using 1.5K resistors for the RL components.
Andrew's build notes for the Cell F Voice panel said:
For regular LEDs use RL = 330Ω-470Ω
forultra/superbrights use RL = 4k7Ω-10kΩ

I may have to change this once I get the board up and running.
Easy enough to do with SMD .


 

Time for the pots and jacks
 Notice the height of the jacks. The switch is taller than usual and this is forcing me to raise the level of the jacks & pots.
 Soldering the pots was a tad tricky. 



You will need 4 of these JFETs


These are the 1K tempcos draped over transistors in QUO and VCO sections




fINAL pics.





Links:
+ NLC Build notes for Cell F Action panel
+ Build notes for Cell F voice

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