TouellSkouarn Strakal Orsel Technical manual

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Strakal Orsel Build Document v1
Your solder joints should look like those shown as ‘OK’ below, they should have that neat
conical shape on BOTH sides of the PCB. If they don’t look the same on both sides then stop!
Work out why from the soldering guides linked and don’t continue until you are getting those
results. This isn’t about perfectionism, you are very likely to end up with a destroyed, damaged
or defective unit if you’re not hitting that standard.
This photo is from the Adafruit guide to excellent soldering - http://bit.ly/1l77tF4 and is
reproduced under an Attribution-Sharealike creative commons license -
http://creativecommons.org/licenses/by-sa/3.0/
Start off by soldering the resistors and diodes
2
220k
R1, R3
5
1M
R2, R4, R8, R12, R14
1
150k
R10
2
100R
R5, R6
1
300k
R7
1
10R
R9
1
33k
R11
1
220R
R13
1
4.7k
R15
You might have a spare 1M resistor in your kit - this is unused.
4
1N4148
D3, D4, D5, D6
(SEE IMAGE FOR CORRECT POLARITY!)

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Strakal Orsel Build Document v1

Page 3
Strakal Orsel Build Document v1
Next solder the Ceramic Capacitors and Film Capacitors.
6
100nF
C1, C2, C3, C10, C16, C22
1
10nF
C8
2
10nF
C19, C20
1
1nF
C11
1
51pF
C18
The 10nF box capacitor supplied will either be yellow/cream or blue

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Strakal Orsel Build Document v1
Now solder the two trimmers, two IC sockets, and the power header, make sure
that the indent on the power header matches the pcb silkscreen, facing away
from the edge of the PCB.
2
5k Trimmers
R16, R17

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Strakal Orsel Build Document v1
Now solder the single transistor - make sure to match the curve of the body with
the silkscreen on the PCB.
1
BF256
Q1

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Strakal Orsel Build Document v1
Now solder the Electrolytic caps, the longer positive leads are marked by + signs
on the PCB
6
22uF
C9, C12, C13, C14, C15, C17
2
4.7uF
C6, C7
3
100uF
C4, C5, C21

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Strakal Orsel Build Document v1
Now it’s time to solder the two LEDs and white tube holders. These are soldered
on the Frontpanel side of the pcb - opposite to all previous components so far.
First place but don’t solder the LEDS IMPORTANT: The longer lead of the LED
must go to the square pad on the pcb. Then place the tube holders - the LED
bulbs should sit around the same level as the top of the holders. This can be
achieved by using masking tape or something similar to hold them in place while
soldering. Now you can solder these components in.
Note: The LED’s supplied with kits have clear lenses but will glow red.

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Strakal Orsel Build Document v1
Now place the rest of the Frontpanel hardware but DO NOT SOLDER ANYTHING
YET. The switches should have one nut screwed on to sit below the panel. Pay
attention to the pot values as shown in the picture below.
1
B1M
Feedback - Boukl Retroaktiñ
1
A500K
Gain - Ampled
1
B100K
Volume - Gounid

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Strakal Orsel Build Document v1
Once you have placed the the Frontpanel and screwed on nuts and washers to
hold everything in place you can then solder in the pots, jacks and switches.

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Strakal Orsel Build Document v1
Now, paying attention to orientation, fit the IC’s into their sockets as shown.
1
NE555
IC1
1
TL071
IC2

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Strakal Orsel Build Document v1
Now finally put on the three knobs and place the tubes all the way into their
holders.
Important: It is essential to have the module switched off when
placing or replacing the tubes! Do not power up this module unless
the tubes are installed!!!
The two Bias trimmers are for gain stages in the circuit. Touellskouarn
recommend setting them in the middle to start off - they can then be adjusted if
desired.