Thursday, 26 June 2014

TTSH - ARP 2600 Replica - PSU - We have the Power !!!

This is the third part of my TTSH (Two thousand six hundred) build.
You can see my full build thread HERE
There are two awesome TTSH threads in Muffs.
2600 clone - Two Thousand Six Hundred (TTSH)
and
Two Thousand Six Hundred (TTSH) Project General Build Thread
The DSL-Man site has a very good TTSH thread
And of course the official build thread is here
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 The PCB before population.
 The 12 squares to the left of the DC-DC block is the internal power distribution bus.

 

 I'm using a AUSTEC DC-DC converter.

My walmart PSU is identical to a Buchla PSU.

12µH Inductor

 Don't forget to cross the beads. Polarity is reversed on the PCB.
A jumper is also needed to the right of the capacitor.
Black is negative, Red positive.

-15V ,0V, +15V

Buchla 250e & 281e - Stage Addressing.

Dueling Buchla 250e and 281e.
Function Generator Vs Function Generator



They work well together.
The top two FGs of the 281e are running independently of each other.
Pulse from the first, CV from the second.


Wednesday, 25 June 2014

Teotihuacan - "birthplace of the gods" - Mexico

Teotihuacan is 48 km northeast of Mexico City
It's the site of many of the most architecturally significant Mesoamerican pyramids in N. America.

 Probably established around 100 BC. It's thought that the city was destroyed around about 550AD

 This is the way up to the peak of the Pyramid of the Sun

 The view from the summit of the Pyramid of the Sun
These are not built of solid stone like the Egyptian pyramids. ... rather, rubble covered with cut stone.

Looking over the Avenue of the Dead
In its heyday, this city came to be the largest and most populated center in the New World.


 This is a view of the Pyramid of the Moon from the Pyramid of the Sun.

This mural of a puma was discovered in 1963. It's part of the Puma Complex" that flanks the Avenue of the Dead.






 From Wikipedia:
Teotihuacanos practiced human sacrifice: human bodies and animal sacrifices have been found during excavations of the pyramids at Teotihuacan. Scholars believe that the people offered human sacrifices as part of a dedication when buildings were expanded or constructed. The victims were probably enemy warriors captured in battle and brought to the city for ritual sacrifice to ensure the city could prosper.[32] Some men were decapitated, some had their hearts removed, others were killed by being hit several times over the head, and some were buried alive.

For more travel postcards click here:

Buchla Acid Train

Testing out the 222e touch controller.
Very responsive.


The 291r filter and 258v/262v are great acid providers.

Some pics:

 The 222e touch controller

 The 222e module

A 259r
 The 291r filter

The 247v sequential voltage source.

 Verbos' 262v - The Harmonic Oscillator

Buchla 200 case on the left & the 200e case on the right.

Tuesday, 24 June 2014

TTSH - ARP 2600 Replica - 2047-1 VCO submodule

This is the second part of my TTSH (Two thousand six hundred) build.

You can see my full build thread HERE
There are two awesome TTSH threads in Muffs.
2600 clone - Two Thousand Six Hundred (TTSH)
and
Two Thousand Six Hundred (TTSH) Project General Build Thread
The DSL-Man site has a very good TTSH thread
And of course the official build thread is here
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The 4027-1 was an improved design over the original ARP 4017/4027 VCO's

The TTSH 2047-1 module is pretty straight forward to put together except for
though those pesky SMD caps. They are tiny and one gave me a headache when it decided to fly off my tweezers onto the floor.

This is a packet of six 100n SMD caps viewed against a Australian 20 cent piece.

Pointless trying to find it. A new order from mouser beckons.



Half way there


1k87 Tempco Resistor.

One finished sub module.... two to go.

As a comparison, I'd thought it would be nice to see the TTSH 2047-1 against a original ARP 2047-1 sub module. This is a spare I have left over from a earlier restoration of a vintage 2600.


The original ARP (like the TTSH version) used three of these 2047-1 submodules. The rest of the VCO circuit is on the main PCB.
 The modern TTSH 2047 uses a 3046 IC. The vintage a CA3086 IC



The CA3046 transistor arrays consists of five general purpose silicon NPN transistors. Two of the transistors are internally connected to form a differentially connected pair.

The CA3086 transistor arrays also consists of five general-purpose silicon NPN transistors. We also have two of the transistors internally connected to form a differentially connected pair.
The pin outs of both look the same.The CA3046's probably have closer tolerances
than the older CA3086, however I wonder if CA3086’s can be used (if you can find them)?
 As in the TTSH build the 2N3904 and 2N3906 transistors are pushed together for thermal contact.

The vintage 4027-1 PCB:(It's a work of art).

Friday, 20 June 2014

Buchla 200e filters - 291e & 296e

Playing around on my 200e.
The sound of a 200e is unique....  it's oh so different from your standard modular. (even from the Buchla 200 & 100 series).
Today I decided to play with the 200e filters... mainly the 296e (spectral processor) & 291e triple morphing filter.
The audio sounds distorted on youtube, but I thought its still worth keeping for the record.
This is my 200e case at the moment. I'm trying to restrict myself to 16U of 200e modules.
There are just 3 filters in this system: the 296e,the 292 & the 291.They occupy 4U/16U
Don B doesn't seem to use filtering very much. The Buchla method appears to be more about wave shaping.
It's not your standard "East Coast" style of subtractive synthesis.

Under this mess there is a 291e. Its a wonder !!!

Basically the 296e processes audio from the 2 VCOs. This is passed to the 291e & 292e.
The 296e also has 16 EGs which can be used to modulate to your hearts content.

The 251e. Its an awesome sequencer with a small footprint.

This is a unedited version of the vid

Buchla 230 Envelope follower / tracker

Some pics of a vintage Buchla Triple Envelope Follower (Model 230) which a friend kindly let me upload.
The 230 is part of a proud tradition starting with the 130 module. Today's modern version is the 230e.
So what does it do?

An envelope follower (or a "Tracker" as the boys at Buchla like to call it these days) is a electronic circuit that takes a signal ( audible frequencies) as input and provides an output which is the envelope of the original signal. That is, it produces control voltages & pulses that are in proportion to (or at least resemble) the amplitude of inputted signals.

It's really nice for producing CVs from drum triggers but most audio with sharp attacks will work.

To quote the official Buchla website:
"In the direct coupled mode (sustained) , pulse outputs are activated when corresponding control voltages exceed 6 volts. Transient coupling permits the detection of attack transients in the presence of background noise and over a considerable range of amplitudes.

And now for some pics of the rear PCB: