Monday 29 January 2018

Sly Grogan - NLC - Build notes

These are my build notes for the nonlinearcircuits Sly Grogan.
Its a envelope generator Eurorack module based on a design in Electronotes #86.

Some pick of the virgin PCB & panel

Get those ICs on first.

-------------------------------------
On Order:
Mouser No:
Mfr. No:
BZX79B2V7
Mfr.: Taiwan Semiconductor
Zener Diodes 2.7 Volt
 ----------------------------------

 The SMD version of the 4148
 Almost there, just waiting on some parts.
 Japanese slang term meaning "butt poke".

While waiting for those components do contemplate the ancient Japanese Art of Kancho.

The 2.7 V zener diode

The 100k trimmer







I used a 820 ohm resistor for the LED resistor. -----------------------------------------
Links
+ NLC Wicki
+ NLC Build notes & BOM
+ NLC Template



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Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html  

Saturday 27 January 2018

Novation BassStation One

I dug this out of storage today with the intention of selling it.
I haven't used it in years.

This original Bass Station came out in 1992. 

It has that cheap black plastic look but I think it still sounds great.


Not too shabby in the TB 0303 emulation department.


Reckon I might just keep this one.


Friday 26 January 2018

Tower of David - The Jerusalem Citadel - Israel

Some pics of the Citadel. This is just inside the Jaffa Gate.

The citadel dates back over 2000 years.
The name "Tower of David" was coined by Byzantine Christians who believed the site to be the palace of King David.



 A view of the Imperial hotel where I stayed from the Citadel.


 Part of the walls & moat of the citadel.

A view of the Church of the Holy Sepulchre.




For more travel links click here:
http://djjondent.blogspot.com.au/2015/03/travel-postcards-index-my-travel.html

227r - System Interface

Some initial tests of a Buchla format 227r.
This is a early rev1 that uses vactrols. It's been many years since I first purchased the PCBs but finally it's working with the help of Dave Brown and his wonderful site ModularSynthesis.
http://modularsynthesis.com/roman/buchla227/227si.htm


A post shared by jono (@dj_jondent) on
Information on this module is rather scarce.

These days music is generally played in a stereo format but the 227r is all about Quad Sound.
It's quite a wonderful module. The 4 inputs can be assigned to 4 speakers (2 front, 2 rear at the four corners of your room). This is all voltage controllable.


All the sounds are patched out via the card.
I'm considering making a breakout cable so this card doesn't have to be left plugged into the patchbay.
I'm concerned the weight of too many cables could cause damage.

Another option is a make a preconfigured patch card:
This patches my chosen outputs through the Tape1/2 & Aux1/2 at the front of the module.


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