Serge Restoration Paperface 2.1

This is the upper panel from box 2

This contains:

• Dual Positive Slew
• Dual Negative Slew
• 2 Smooth and Stepped Function Generators
• 1 Dual VC Slew Generator
• 1 Peak and Trough 

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 The lower module is the negative slew
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NLC PSU build 2

This is a smaller version of a Nonlinearcircuit PSU I built earlier.
http://djjondent.blogspot.com.au/2017/02/power-supply-nlc-build-notes.html

It uses a 12VAC Wall Wart power adapter.
The AC output of the wall wart is rectified with diodes so that positive voltage gets stored on the caps that serve the positive voltage regulator (LM7812) and negative voltage gets stored on the caps that serve the negative voltage regulator (LM7912).

I'm putting together this PSU for an old Serge modular but its actually for Eurorack.
The serge uses +12, -12, +6 and ground so I will have to add a 6V regulator to this later.

Some pics:

The PCB receives 12VAC from a plugpack/ wallwart

. The 1N4004 diodes split this into positive and negative waveforms.

The 4700uF capacitors then smooth out these waves

. The 7812 and 7912 regulators then convert the rectified & smoothed

signals to +12V DC and -12V DC and these are fed to the connectors to be distributed to your lovely modules.

I'm using 250v TDK film caps for the four small 100nf caps

 Poor Grandma.
Let's Eat Grandma is a British musical group formed in 2013 by childhood friends Rosa Walton and Jenny Hollingworth. 

I decided to use 1K resistors for the LEDs

 Some pics of the additional 6V regulator circuit.

 Using a LM7806

 330nf on the left. 100nf on the right.

Red +12V, Black 0V, White -12V, Green +6V

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A second build.
I have a very confined case.

 tRYING TO keep everything as flat as possible.

Hsinbyume Pagoda - Myanmar (Burma)

This beautiful all white structure on the banks of the Irrawaddy river just North of Mandalay.

 The pagoda that is also known as the Mya Theindan Pagoda.It is located in the Northern part of Mingun town near the massive Mingun Pagoda.

 The all white pagoda was built in 1816 by Prince Bagyidaw.

..

The structure was dedicated to his first wife, Princess Hsinbyume, which literally translates to White Elephant Princess, who died during child birth. During the large earthquake of 1838 the Hsinbyume Pagoda was severely damaged.

Paperface Serge - Negative Slew restoration

Serge  Negative Slew restoration.
These are some notes for repairing a old Negative Slew.

The main panel is here
http://djjondent.blogspot.com.au/2017/06/serge-paperface-restoration-warren-burt.html 

The board is marked R9

This is the lower section of the PCB.
The upper section works.
According to Ken Stone's site there are two problems with this.
It's missing one trace and a 4.7k resistor.

I've marked the missing trace in orange.

Also marked the missing 4.7k resistor in orange.

4.7K resistor added.
I removed the 3900 opamp. lots of corrosion in the socket.
Replaced & it works.
:-)
Thanks Ken

Links:

1. SergeSynth.net

2. CGS

3. Muffs

The 1973 PCB used +12, +6, -12 & ground.

The 1975 PCB used +/-12 V & ground.

So I'm guessing this is a 1975 PCB  as it uses +/-12 & 0V unless it has a on board 6V regulator.

The module uses two ICs

LM3900. It's a quad op amp

 Ground at pin 7, power is pin 14.

LM3046 

This is a transistor array.

It consists of five general purpose silicon NPN transistors. Two of the transistors are internally connected to form a differentially-connected pair.  

PCB connections:

A = input (1)
B = output (1)
C = VC (1)
D = pulse out (1)
E = input (2)
F = output (2)
G = VC (2)
H = pulse out (2)
U = not used (0v)
W = 0v
X = +12v
Y = +6v
Z = -12v

Eloquencer - master track length

 This can be accessed by pressing Function & the clock button.

 

The Master track length changes the reset point of the pattern when master track is set to INT'.

 

The default is 16

 

 

It has a  max of 64 steps. 

This is not to be confused with making longer sequences.

 

 If I want to extend the length of my sequences to 32 I just need to chain two 16-step patterns. 

If I want to make a 64 step sequence, just chain four 16 step patterns

 

 To explain better what the Master Track Length really is I'll quote something I read in

 the WM forum

"Let's say I chain A1 and A2, MT is INT, and MTL is 16. When I press play the Eloq would play 16 steps in A1 and then will reset, so it will jump to the next pattern (A2). It would play 16 steps in A2 and will to jump to A1 again.  A1-A2 > A1-A2

If I set the configuration where MTL is 32, Eloq will play 32 steps in A1 and 32 steps in A2, so that would be like playing A1-A1-A2-A2 > A1-A1-A2-A2"

(Winter modular forum) 

 So in other words, making the master length to 32 will make the pattern repeat.