Thursday, 27 September 2018

Egypt - Felucca

Some pics of the felucca that I sailed on while travelling down the Nile.

. Its rig consists of one or two lateen sails.






As well as providing transport, we slept on the boat.
Though cramped at times it was so much fun. So many friendships made on the trip that I still have today.

When the wind stopped blowing we had to row. :-)

A traditional Egyptian drink



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3 trins RGB +1 - plugin SPST & SPDT

Some pics of my build for the 2nd of 4 new plugins for the 3-trins video synthesizer by

Gijs Gieskes

The official plug-ins page is here.
http://gieskes.nl/instruments/files/3TrinsRGB1/Plugins/

 *****3trins facebook******


This is slightly different to the previous 2SPDT/4SPST build.

This SPST & SPDT uses a CMOS 4066. It's a Quadruple Bilateral Analog Switch.


The SPST&SPDT behaves like a CV controlled switch.
There are just 2 switches:
Switch A on the front & switch B on the rear.

Switch A has the following connections (on the extreme right in the photo above):
<> 1CTRL: Toggle input
<> 1Anc: Normally connected
<> 1Bno: Normally open
<> 1AB:Pole/common connector

The  "1CTRL" input is where you plug your modulation source (such as a LFO).
The pot on the right appears to modulate the 1CTRL input

Switch B on the rear has these connections:
<> 2CTRL: Toggle input
<> 2Bno: Normally open (multiple connection)
<> 2Bno: Normally open
<> 2Ano: Normally open

The  "2CTRL" input is where you plug your modulation source (such as a LFO).
The pot on the left appears to modulate the 2CTRL input
2n3904 TRANNIE



tOP header


Testing the perspex guards.... the transistor needs to be bent down for everything to fit.


Example patch:

So you take a signal, eg video from the header and patch it to 1AB.
Then run G- to 1Anc and B- to 1Bno.
Now patch one of the LFOs (eg F01a) to 1CTRL. The knob on the right appears to set the point where switching occurs ...you should start seeing the video input jumping from B- to R- in time with the LFO.

The B side is similar, but it just connects two points On or off, instead of the A sides 'this or that'.



A post shared by jono (@dj_jondent) on
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3 trins -video synth plugin - 2xSPDT & 4XSPST

Some pics of my build for the 1st of 4 new plugins for the 3-trins video synthesizer by
Gijs Gieskes

The official plug-ins page is here.
http://gieskes.nl/instruments/files/3TrinsRGB1/Plugins/

 *****3trins facebook******


This (as the name implies) uses 6 push button switches.
Two single pole, double throw (SPDT)  & four  single pole , single single throw (SPST)
Looks like switches A & B are the SPDT.
Switches C,D,E,F are the SPST
These will turn on & off any extra connections you that you choose to make using the upper header patch bay.
 
aND the other side:


 The upper header first;
Finished.
Such a simple build. Now to try some patches:

tHE switch system is really cool and easy.

The inputs and outputs of the SPDT switches (buttons A & B) are on the left of the module.
Connections for Switch A is on the front & for switch B on the back.
 For switch A:

So you would connect any inputs to AP1 and outputs to AT1 & AT2
-----------------
The right side (front) has connections for the C & D switches.

That same side on the rear has connections for E & F. (FR,FT & EP,ET)


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Sunday, 23 September 2018

246 Buchla Format Build notes - 3

This is part 3 of my build notes for the Buchla format 246 module.
It's a replica of the Buchla 246 sequential voltage source.
 
Above is a photo of a vintage one.


 My earlier posts can be found here:
 
 These are just my personal build notes.
I'm not a pro technician. 
These pics and notes as just to help me trouble shoot should I run into any problems.
 
The 246 can be built without modifications. I have one of these which works well.
This particular build uses the Modular Synthesis mods.

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

Don't install
 R279, R280, R281, R282, R283, R284, R285, R286, R287, R302, R303, R304
I've marked these with a white pen


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Clock Waveshape
 
"The waveshape is similar to the 245 but the baseline sits at 4V, not 2V (I believe) due to the number of stages. When all the stage pulse output resistors were changed to 6K8, the module would no longer advance."
To fix this issue adjust the clock waveshape trimmers until it functions reliably.
 
 
 This is the waveshaper section on PCB2.
Change R301 to a 10K trimmer.


PCB2
Change R306 & R315 to a 20K trimmer (wiper at the node connecting R306 & R315).
 


Photo x 2 *

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Diodes

Looks like they are all standard 1N457 
D1, D2, D3, D4, D5, D6, D7, D8, D9, D10 
mouser 512-1N457

10K resistors first

1K resistors, etc etc
 

 
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100K trimmers
mouser 858-25PR100KLF

 
I used a different footprint one on TR2
still 100k



----------------------------------
Time to install the transistors

Don't install Q75, Q76, Q77, Q79.
These are 2N3906
Connect the base to the collector with a link on Q75, Q76, Q77, Q79.
 

 

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

The waveshaper section is completed
 

-------
Q5 is a JFET
.... a junction field effect transistor.
 
 
 


 
-------
LS312 
package: TO-78
This is a TIGHTLY MATCHED, MONOLITHIC DUAL transistor
 

 


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Replace IC31, IC32, IC33, IC34 with LT1637.
These are Precision Amplifiers
 
 

 
We need to
swap pins 2 and 3 of IC31, IC32, IC33, IC34.
 

That is the input & output pins are reversed. 
Ive modified the back of the PCB
...


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LM311 
IC7, IC9, IC10, IC12, IC13, IC15, IC16, IC18, IC19, IC21, IC22, IC24, IC25, IC27, IC28, IC30

photo*
 

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LM741 
IC2,
photo