Wednesday, 26 May 2021

Vitalise - last week

 

106-108 George St, The Rocks NSW 2000, Australia
Tomorrow at 6 PM UTC+10 – 11:55 PM UTC+10

Tickets
 
 s.c.h.e.m.e - Sydney City Humanoid Electronic Modular Ensemble
terradatkill
john jacobs
Лучи Мечты
bushranger
-
DJ cinnamon (aka zimt)
RESIDENT DJ CHRIS MOUNTFORD
resident vj atmm

I can't believe it's not a VCO - NLC Build notes

These are my build notes for the eurorack module "I can't believe it's not a VCO".
ICBINAVCO ???
 
The module is 8 HP wide and is based on ideas presented in Electronotes #132.

Andrew describes its as a "VCF with a 'filter exciter' section to allow a wide variety of acoustic, semi-acoustic and not-acoustic-at-all sounds". 
 
The filter is pinged and its output is fed back into the circuit via a VCA I think.

I guess the only way to find out is build one.

 
 
 
 
 
 
 
 

hERE are some closeups of the PCBs
Its all SMD, though still pretty easy 0805 size,
 
Looks like there are two ways to use this module.. either in VCF or VCO mode.
Its really a filter that can be used as a VCO.
I like multipurpose modules.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
The TL074 & TL072 op amps first.


LM13700M - on order
It's a Transconductance Amplifiers.


I have a few 
Mouser No:
513-NJM13700M

I'll try these .




Next the LL4148 diodes
The order is odd I know. I'm installing the parts I already have.


Ordered the 5V1 zener
863-MM3Z5V1ST1G


BC847 & BC857 


BCM857DS
SOT457 Mouser: 771- BCM857DS-T/R
 
Watch it's orientation.


I'll use these amps:
NJM13700M
I have some left over from building the NLC Cell Voice panel




Waiting for parts .. to be continued.





Links:



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

Sunday, 23 May 2021

Buchla format 296r

 This is a Buchla Format, Roman 296r.

Its one of my favourite modules in this format.
A huge amount to time went into building this.
Lots and lots of capacitors

An evolution from the 294, 295.


It's complex but basically its 16 filters with VCAs and envelope followers.
Two of these and you can make a vocoder.

Saturday, 15 May 2021

Mogue mixer & VCA - NLC build notes - part 2

 I started this build back in 2019.
Finally catching up. Sorry for the delay.
I blame a combination of slackness and covid.

Part one is here.
Mouge Mixer/VCA- build notes
 
The Moog CP3 is a classic so its  always interesting to study the circuits.
iT HAS two (inverted) outputs. : a +ve & a -ve 
It also has a passive mix bus without the use of op-amps.
The module uses transistors.

And I was unsure what parts to use. The LM394 is obsolete.
What to do? Should I use some cheap Chinese copy off Ebay , ... or maybe a Russian clone ???
I decided to try some matched some BC547s first.

The LM394 consists of a pair of super matched NPN transistors
The Emitter-base voltage is matched to 50 mV


The BC547 is also a NPN transistor


First , you need to match the BC547s.
Here is some info on the subject of matching

Vbe (base-emitter voltage) matching is the most common type of matching done.
I like using a Atlas DCA Pro DCA75  




 

Installing headers


pOTS and jacks next.

 


Still testing the transistors.
They need to be matched as closely as possible.

The mixer actually has 2 outputs: a +ve and a -Ve.
It's what you'd expect from a CP3 mixer.
However, the -ve is fed directly to the switching pin of the VCA input.
This output is somewhat distorted.
The +ve output is the jack directly below IN2
 
 

And YES
It does work with the BC547's
You don't need to buy clones from Ebay.


Links
+ NLC blog
+ official build notes & BOM
+ FB builders
 
---------------------------------------------------------------------------------------------------
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html 

Wednesday, 12 May 2021

Vitalise - Week 7

 

For week 7 of 9, there are  five live acts: 
 
LIVE:
====
Unkle Ho
Loose-y Crunché
AUTO64
Nick Dan
Brendon John Warner
guest DJ: Cinnamon (aka Zimt)
resident DJ: Chris Mountford
resident VJ: ATMM


MST MIDI to CV Converter - sYNTHROTEK - part 1

 Building my first kit in a long time.
 

Finding a MIDI to CV converter is pretty easy in Eurorack format, but CV to MIDI clock converters
are rarer.
I'm looking for a module that will convert analog clock to MIDI clock.
Hopefully this will do the job.


according to the manual it does:
1. Clock input to DIN MIDI & USB MIDI CLOCK out
2. MIDI CLOCK to CLOCK OUT





Build notes (official)

The official build notes are great.
My notes are just to help me trouble shoot should I encounter any probs.
 
The supplied kit makes everything easy.
Sourcing parts is often more that half the work.

There are 2 boards: Logic & control.




Diodes first
all are 1n4148s


The 20Mhz crystal.
This is the clock source.

Caps next.
there are six 100nF caps - do these first.
c1, c4,c5,c9,c15,c16.

Four 51pF caps
c2,c3,c6,c8



Two 15pF ceramics
c7,c11
These go either side of the crystal


Electrolytic caps
c10, c13,c14

IC sockets


Spacers - standoffs -- headers

Once you screw in the standoffs, soldering the headers is easy.


Power (10 pin).
Switch & i2c header
 
   

 


The red switch sets the midi channel.
It's kind of a reverse binary number system
 
offoffoffoff = binary 0 = Midi 1
ONoffoffoff = binary 1 = Midi 2
offONoffoff = Midi 3
 .......
offONONON = binary 14 = Midi 15
ONONONON = midi 16 
etc






thAT  square shaped black socket is the header for a i2c connector.
It connects to the expander module.

Time for c12 
The 220 nF capacitor  is pretty big so needs to be twisted a bit to fit in nicely.

transistor voltage regulators
VR1 - 78L05
supplies 5V
 

TL431
U3
This is a shunt regulator or to use its long description, its a
programmable precision voltage reference IC.
 
It's a regulator diode whose output voltage can be programmed by changing the value of resistors connected to it. It's probably being used here to provide a voltage reference.

 

To be continued ......

Part two is here

MST MIDI to CV Converter - sYNTHROTEK - part 2

 


Links