Frequency Central Little Melody, Build Documentation

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Key to PCB screen print:
n:
This signifies NPN BC547 transistors. Note the correct pinout as shown by the half circles.
Please observe the correct polarity for all ICs, voltage regulators, diodes and electrolytic
capacitors.
Bill of Materials
330R x 1
1K x 14
10K x 7
12K x 2
100K x 8
100K 1% x 3*
All resistors ¼ watt
metal film.
10nF x 2
100nF x 2
**
10uF x 1
47uF x 2
TOOL PIC
TL084 x 1
TL072 x 2
BC547 x 6
1N4148 x 3
78L05 x 1
3mm red LED x 6
14 pin IC socket x 2
8 pin IC socket x 2
B100K x 2 metal
shaft
B100K x 4 sliders
B100K x 4
(or these) ** *
plastic shaft
10K trimmer x 1
3.5mm socket x 5
Tactile switch x 2
Male header x 1
(cut to size)
Female header x 1
(cut to size)
Power header x 1
Knobs x 2
Slider caps x 4
****
* They don’t have to be 10 0K exactly, they just have to be matched to each other, so for
example if they are all 99.9 K that’s fine. Grab a bunch of 1 00K resistors, measure each
one, make little piles of 100k, 99.9K, 99.88K etc. Before long one of the piles will have
three
resistors in it, that’s your matched set! Should only take 5 minutes.
** Early rev PCBs show 100nF x 3, one should be replaced with a jumper (see text below).
*** I prefer the Song Huei tall trimmers because they have a longer shaft and a white
notch.
**** Yes,
these , despite the description.