Showing posts with label DIY. Show all posts
Showing posts with label DIY. Show all posts

Tuesday, 15 August 2017

Feague - NLC - Build notes

These are my build notes for the Nonlinearcircuits Feague module.

Feague is defined as:
"To decorate or improve in appearance through artificial means.. To increase the liveliness of a horse by inserting an irritant, such as a piece of peeled raw ginger or a live eel...."
 
This module is a 4 pole filter and Quadrature oscillator in Eurorack format.
It has 4 outputs, each 90°phase shifted, two CV inputs, a signal input, sync input and a hi/lo range switch.

It looks very similar to a module Andrew built into his Serge format Drum Panel.
Andrew described this as:
Quadrature Oscillator (QUO) / Low Pass Filter (LPF) with chaotic feedback.
It can be switched to perform as a very low freq QUO, quadrature VCO, LPF with Q and a pot
allows non-linear resonant feedback to obtain richer and irregular harmonics.

Below is a panel and bare PCB for the Eurorack version.
Andrew's build notes are here:
http://www.sdiy.org/pinky/data/FEAGUEbuild&BOM.pdf

A Quadrature oscillator is a phase shift oscillator.
 It uses an op amp integrator to obtain a full 90° phase shift.

 Here is a simplified circuit to demonstrate the principle.

 In this video Andrew is demonstrating two Feagues. The one on the left is used as a VCF and the right as a oscillator (QUO). QUO mode is obtained by cranking the Q pot up to 9-10

Back to the build. The virgin PCB:

Get those ICs on first.
We have three TL074 (Op-amp), two LM3700 (op-amp) and a DG411
The DG411 is a multiplexer
Trannies on next:

Some NLC words of wisdom:
Monday Morning Gunk.


The BOM requires:
a S1JL rectifier
Mouser No: 821-S1JL.
There is a long waiting list for this.
A replacement is  Mouser Part No: 583-FM4005-T.
The rectifier is polarized. The cathode end is marked with a band. 


This replacement is slightly too big for the PCB. so i had to solder it on its side.


Rest of the Thruhole and passives.



Resistor RL - for LEDs. I'm using 470R.
Resistors marked with a "C" = 100K
 Don't forget the Tempco  resistor. The LEDs colour isn't imporant.

 Headers next. Install the heareds before you install pots and jacks



Time for the Jacks & pots

Time for the last 4 LEDS.


You can use this module as either a VCF or Quad Oscillator.

"To use as a VCF keep the Q pot at zero.
Patch in an audio signal and adjust the Coarse freq pot and Q pot to use as a filter.
Keep the switch on Hi, add CV as you like. Once sounding good, try tweaking the nonlin Q pot and see what you get. "

To use as a Quadrature Oscillator
"Keep the nonlin Q pot at zero then turn up the Q pot until the module starts to self-oscillate
(around 8-9).
Adjust the frequency with the freq pots.
When the switch is Hi the range is at audio rates, set the switch to Low for LFO rates.
When using the module as an oscillator, the nonlin Q pot can be used to adjust the amplitude of the output signals.
Don’t forget to play with the sync input; it is more like a freeze function."



Links:
+ NLC Build notes
+ NLC Blog
-----------------------------------------------------------------------------------
You can find more NLC builds here.
---------------------------------------------------------------------------------------


Tuesday, 1 August 2017

8 Bit Cipher - NLC - Build notes.

These are my build notes for the NLC cipher Eurorack module.
It is based on the Buchla SOU - source of uncertainity --- the best place for random
CVs and gates.

The 8-bit can produce 4 CVs and 8 gates.
It requires 2 inputs:
1. Clock
2. a signal on at least 1 data input.

Any signal crossing 1V can be used as a clock or data signal.
Leave the clock signal steady and vary the frequency of the signal to the data input.
Also try different wave-shapes such as square, sawtooth or triangle


sOME NLC words of wisdom:

ICs first.
Now for the through hole stuff:
Headers to join the 2 PCBs.
Install the Jacks & LEDs


Links:
- NLC build notes
- NLC blog 
- NLC panel - CMOS (Serge format) 
- jondent blog - The cipher section of the serge/CMOS panel 

..

Works well with Buchla.
.

The upper 9 jacks are trigger outs.
000 to 111 are binary for 0 to 7.
Super serial = ??? Its another trigger out.
CV1 to CV4 are outputs.
The CV outputs are all related to each other but are all different; part of CV1 is fed to CV2, part of CV2 is fed to CV3 etc.
 
The lower row are all inputs.

"The strobe input makes it a bit like an 8 bit sample and hold.
If nothing is inserted into the strobe jack the module carries on as normal. When a signal is introduced to strobe, the data obtained from the data jack is only loaded onto the outputs when the signal is high. "
-----------------------------------------------------------------------------------
You can find more NLC builds here.
---------------------------------------------------------------------------------------

Monday, 31 July 2017

Serge Bi-directional Quad switch - build notes

I've been searching for the perfect synthesizer router for my Serge.
The Serge Bi-directional router is fine but I would love to have more ins/outs.
Recently I built a NLC 32:1and NLC Router for Eurorack.
All excellent and I might one day adapt one for the Serge.
One I haven't tried is the serge Quad switch which seems to be an adaptation of the earlier
Serge Triple Bi-directional R.

The module I'll build is the Cat Girl Synth CGS 88.
Ken's Build notes are here:
https://cgs.synth.net/modules/cgs88_bds.html

The Quad switch uses a CD 4013B.
Its a CMOS Dual D-type flip flop that works as a two bit binary counter.
Looks like the switch used in the vintage 1970's module was a Motorola MC14007UB.
It was mounted on a separate board off the original R4 PCB.
You can still find these.

D = Drain, S = Source.





to be continued..... waiting for parts.

Sunday, 30 July 2017

Router - NLC build notes

Some build notes for the Nonlinearcircuits router.
I'm hoping this will function something like the Serge bi-directional router, but with 4 outs rather than two.
A router can also be found in the NLC Chopper.

The new NLC Router is a voltage controlled switch that can deliver 1 into 4, 4 into 4 and 4 into 1 at the same time, 2x 2 into 2 and, with a simple mod to the PCB, 2x 1 into 2 



This looks like a easy build.
ICs on first.
The module uses a DG412 which is a CMOS analog switch.

Control inputs are pins 1,8,9,16 (in)
D1–D4 : Analog Switch Drain Terminal
 S1–S4 : Analog Switch Source Terminal

Passives, resistors, diodes, caps
The thru hole stuff.


Jacks & pots.
Nice.

Input 1 is internally connected to the switches on jacks 2, 3 & 4.
CV 1&2 is internally connected to the switch on the CV 3&4 jack.
The signals to the OUT ALL jack are summed together

The Router pots can be used as switches, 0 is off and 10 is on. At these settings the switches will ignore incoming CV or gate signals. For the switching to be controlled by CV or gates, set the pots to an appropriate turn-on point.

 Links:
- NLC build notes.
- NLC blog
- Facebook
- Muffs2016

-----------------------------------------------------------------------------------
You can find more NLC builds here.
---------------------------------------------------------------------------------------