Thursday, 28 February 2019

Orbital Gig - Enmore Theatre - Sydney

Orbital gig Thursday 28th Feb, 2019




A post shared by jono (@dj_jondent) on

My ears are still ringing from this gig. Brothers Phil & Paul Hartnoll put on a great show last night.
 Orbital have been making music for as long as I can remember ... many decades.
The name of the band came after the M25 .......the ring road around London. I remember hearing their Dr Who theme as a kid(which they did play tonight). That track ignited my love for Electronic Music. It was awesome to hear it again.

They haven't abandoned their roots in 303 Acid. There was lots of use on a Roland 303 last night.
I think the drum was a Tempest. I did also spot a Matrix Brute.
The visuals were overwhelming ...making political comment on poverty, homelessness, Brexit, the royal wedding..






Severed Heads - Enmore Theatre Sydney 28th Feb 2019

Saw Severed Heads last night at the Enmore in Sydney.
They were supporting Orbital. Great gig.
Complementing the sound were amazing visuals. Some were shocking & at times gruesome ... reminded me of Francis Bacon . It was a shame that the Orbital rig was in my line of sight and blocked my view a bit.

Severed Heads have been a a big part of the Sydney electronic music scene since the 1980s.
Most people will remember them for the single "Dead Eyes Opened".
They originally released this in 1984 but it was remixed in 1994 and re-released, the latter version reached No. 16 on the ARIA Singles Chart. You may also know them from classics such as "Big Car" and "A Million Angels."

I hope Tom Ellard will keep this band going for many more years to come.

I'll post some better videos later on this page.
 

Wednesday, 27 February 2019

Mogue mixer & VCA - NLC build notes

My build notes for the Nonlinear circuits Mogue.


MOGUE is a VCA and Mixer inspired by early Moog designs... The mixer section was inspired by the Moog CP3
 

Andrew has made some changes to get the outputs into +/-5V range and for using easily available components.

The old Moog schematics:




The LM394N
Bipolar Transistors - BJT 
https://au.mouser.com/ProductDetail/Texas-Instruments/LM394N?qs=czFRc4EZNJgyK3N2awTVPQ%3D%3D

Another option are SSM2210s
The SSM221s & LM394Ns are matched NPN transistors. They are both obsolete.
One option is to replace these with Russian Clones: AS394 matched transistors.
Or you can try your luck with the Chinese ones on ebay.
I'm going to try using two BC547's first.
-----------------



Used this;
771-BCM857DS-T/R 
orientation ??? the dot marks pin 1 ???
I'm not sure of the correct orientation.
I think the dot marks pin 1

 Tayda



Links
+ NLC blog
+ official build notes & BOM
+ FB builders

to be continued...................

Tuesday, 26 February 2019

Ian Fritz - Hypster - NLC module

Some of my personal pics and build notes for the Ian Fritz Hypster module.
This version is NLC / euro module.

The Hypster is a hyperchaos module.


In Ian’s words -"It's fourth-order hyperchaotic, with voltage control of the main parameters, including exponential control of the cycle rate". 

 
"Hyperchaos is chaos on steroids, with the mathematical divergences being generated in more that the usual single dimension. The module is a unique, original design featuring voltage control of the main system parameters...............


...............With an eight-signal output it can simultaneously control a large number of synthesizer parameters or generate multiple audio waveforms for individual processing". Ian F.

The module ranges from a few kHz down to approx. 5 minutes per cycle so is great for CV and audio duties.


Using this transconductance amp (from the Cell Voice build).
Mouser: 513-NJM13700M-TE2


My bi-polar LEDs are green/red.
I used 470r resistors for these.


 To be continued...........

Links:
+ The electronic Soundhouse - Ian Fritz' site
+ Chaos Theory for synthesizers - Ian Fritz
+ NLC blog
+ BOM & Build notes
+ Muffs
+ NLC Facebook builders Guild


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



Sunday, 24 February 2019

Tec 1D - computer

Some build notes for the Tec 1 computer.
This is a kit that came out in the early 1980s. 
It's a single board computer with readouts in the form of a seven segment display.
It contains it's own PSU.  It will also operate from a 6V battery. Battery back up is useful to avoid
loosing any programs written into RAM.
There is a 7805 regulator which keeps the operating voltage at 5V.
The PC layout of this board was done by none other than Ken Stone.


Notice the keyboard in the lower right of the photo. ... its really a keypad made up of switches. These are labelled with hexadecimal  numbers 0 to F. There are also 4 switches.... labelled AD, GO, + and -.

AD = address
GO = excute the address (pushing it twice will run any program entered into the computer)
"+" = increment the address
"- " = decrement the address

This single-board kit computer was first produced by the Australian hobbyist electronics magazine Talking Electronics. It was featured in 1983, in Volume 1, Issue 10 of the Talking Electronics magazine, pages 57 to 75, with relevant chip data presented on the rear cover.

 An early Tec-1 built by Ken Stone

Issue 11 featured add ons for the tec 1 --- ( two peripherals designed by Ken Stone for the TEC-1 -an 8x8 matrix display, and a relay driver board, allowing the TEC-1 to be interfaced to other equipment). 

Volume 1, Issue 12, pages 13 to 38, had the third installment, including an interface for a simple plotter  and a RAM expansion. TEC-1A was introduced in this issue with the PCB artwork presented on the inside rear cover.

Volume 1, Issue 13, pages 9 to 26, had the fourth installment, including a power supply designed specifically for it, and a non-volatile RAM module to allow data to be retained, even after the TEC-1 was powered off.  (Wikipedia)

I'm building this as its a great way to understand basic computer architecture and learn the facts and operations of programming from ground level.

This is a TEC-1D Reproduction by Ben Grimmett (2018) It is based upon the PCB artwork of the TEC-1D
The unpopulated board.

The board came with a specially programmed chip ... called an EPROM (electrically programmable memory). The original board used a 16k bit 2716 EPROM.The new board requires a 32k bit 2732. 
It is organized as 4,096 words by 8 bits. 
This is directly above the speaker which can be used to play music.
The EPROM is NMOS Type with a UV Erasable Window

That is it is housed in a 24 pin Window CeramicFrit-Seal Dual-in-Line package. The transparent lid allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can be then be written to the device.

The computer contains 2K of RAM... programmed in machine code.
Machine code is very memory efficient and has a fast execution rate.... making high speed programs possible.

ic headers first.

A bit about the chips used in the original computer:
+ 8212 - Display Driver 1 --- drives each digit of the display
+ 8212 - Display Driver 2 --- drives segments A to G of the display
   (The 8212s have been replaced with 74LS273s. 
These are D-type flip flops....... also known as a latch ICs)

+ 2716 - EPROM
   (the new board uses a 2732 EPROM)

+ 6116 - RAM
+ Z80 - CPU
+ 4049 - CMOS - the oscillator for the clock.
+ 74LS138 - (Logic gate address decoder) selects between EPROM (2716) & RAM (6116)
+ 74LS138 - (logic gate) selects between keyboard and display


Simplified block diagram.

The ROM contains all the information to start the computer and keep it running

The Z80 CPU is the arms and legs to which all instructions are sent. It does what the ROM requests.

The Z80 selects which device it wants to address by one of the  two decoder 74LS38s
Because each decoder has only 4 outputs, we need two of them.

 
(Each 74LS38 logic chip has 4 gates with 2 inputs and one output).
Each selects one of 8 output lines.... going to the Keyboard or display & the ROM and RAM.


The 8212 Latch ICs (or 74LS273) drive the two LCD displays. 
Because each has only 8 outputs we need two. The displays are multiplexed. The Z80 constantly feeds info into the displays via these 8212s.

The 74c923 chip feeds into the keyboard. The keyboard is constantly scanned by this chip. It scans the keys looking to see if any have been pressed.
If a button is pressed the 74c923 sends a 5-bit binary number (corresponding to the key).
Eg if key 5 is pressed it sends the number 00101.

The 2716 ROM tells the Z80 what to do when that binary number is received.

The 6116 is  SRAM .... static RAM.
DIP-24 CMOS STATIC RAM 16K (2K x 8 BIT) IC
 (There are 2 types of RAM ... Static & Dynamic)



Links:
+ Retro computing
+ Volume 1, Issue 10 of the Talking Electronics magazine
+ Talking Electronics Issue 11 
+ Talking Electronics Volume 1, Issue 12 
+ Talking Electronics Volume 1, Issue 13
+ Retro Hansotten  
+ Ken Stone Video
+ Video - Tec 1 computer
+ Holden
+ Wikipedia

To be continued......

russia - Moscow 1 - some old pics

These date from 1998.. 20 years ago.
Lots of great memories. I hope to be returning to Russia soon.


A pic from my old travel journal.


 aRT by Moscow river

Behind Red Square

 Church in Red square

Dangerous lift ??


GUM department store

 Inside Kremlin

 Inside Kremlin
 Inside Kremlin
 Inside Kremlin

Inside Kremlin






For more travel postcards click here:

291r - build pics

some pics of a Buchla format 291r...

The old Rev 1 291r used 2 PCBs.
These aren't official build notes, just pics to help trouble shooting the build.


The cost of parts when building a 291 is very much tied up with the vactrols.
I'm using NOS VTL5C3/2. These average $20AUD each. There are chinese clones out there but I haven't used them yet. I think its better to use the original VTLs for this filter. if you can find them..


"The VTL5C3 (and VTL5C3/2) is what I refer to as the 'golden' Vactrol because of its response characteristics - I.E., the curve of its response when transitioning from dark to light and light to dark resistance. This curve, I believe through sheer serendipity, closely mimics the percussive envelope of certain natural objects. This response molds sharp transients into very 'organic' type responses. The response can range from a malleting sound, a 'thwipping' sound, or a plucking sound, depending on what's going on at the time. Interestingly, this response adapts to how *hard* or *soft* the transient is (in terms of amplitude) just as a natural object such as a string or drumhead would react when being plucked or struck softly or with more intensity." Scott Stites









This first build of mine was partly successful. I experimented with different pots on the upper and lower filters. The upper filter was most successful.

 I've seen a few suggestions:
Pot 1. Resonance Q: = 5K .... trim pot
Pot 3. Bandwidth Input:=  10K (Lin)
Pot 5. B.W. (CV) = 10K
Pot 2: FM: = 50K Lin
Pot 6. C.F. (CV) = 10K
Pot 4. Centre Freq = A10K

------------------------------------------------
I purchased  this 291r a while back which sounded great.

It was unusual as the pot choices were different to what I've used before.










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

Building v2 of the 291r filter.
The BOM says:






20K LIN POT1, POT7
9MM VERTICAL 652-PTV09A-4030UB203

10-100K LIN POT3, POT4, POT5, POT6, POT9, POT10, POT11, POT12
16MM ANGLED
http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-16mm-right-angle-pc-mount/

10-100K AUDIO POT2, POT8
16MM ANGLED
http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-16mm-right-angle-pc-mount/

decided to stick with the  20K for the pot 1 & pot 7
and now use 100K A for pots  2 & 8 - (FM input).

we sill see how this sounds.













Links
+ electromusic