Frequency Central High Towers User manual

Frequency central
Build documentation for:
High towers
Featuring code by Jetroid
Main PCB Control PCB
High Towers is a 4 channel programmable and addressable clock divider. It is more than the
sum of it’s parts.
High Towers internal operations can be considered as 4 clock dividers slaved to an incoming
clock. The 4 clock dividers are labelled A, B, C, and D, the divisions for each divider may be
selected using the presets and the individual division selectors. The clock dividers can be set
to count up, down, or to one of a variety of modes that move between counting up and
down. Furthermore, the division of each clock can be set by external CV.
For further information see the High Towers User Guide.
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
You will notice that all of the components listed below are also hyperlinks to where I buy
each specific part from. You can also use the hyperlinks to find out more about what each
component looks like. If you want to know even more, Google is your friend.
1K x 25
10K x 7
All resistors ¼ watt
metal film.
100nF x 1
10uF x 1
47uF x 2
TOOL PIC
TL084 x 1
TL072 x 1
BC547 x 6
1N4148 x 6
78L05 x 1
3mm red LED x 6
14 pin IC socket x 2
8 pin IC socket x 1
B100K x 2 metal shaft
B100K x 4
(or these)* plastic shaft
SPDT toggle x 1
3.5mm socket x 12
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
* I prefer the Song Huei tall trimmers because they have a longer shaft and a white notch.

Main PCB assembly
1. Solder the diode and all resistors
2. Solder all three IC sockets
3. Solder the non elecrolytic capacitors
4. Solder the 78L05 and BC547s–watch the polarities!
5. Solder the box power header. Make sure the notch lines up with the screenprint
legend. If in doubt, have a look at a power cable, and make sure when inserted into
the header the red stripe lines up with the -12V screenprint.
6. Solder all electrolytic capacitors
7. Cut male headers to size and solder them into place. Make sure that they stick out of
the bottom of the PCB.

Control PCB assembly
1. Place the PCB on a flat surface. Place the 2
tactile switches into their solder pad. Do not
push them all the way through, they should sit
proud of the PCB (see photo), their legs should
not protrude through the other side. Solder
them into place from the top of the PCB.
2. Solder the 8 resistors.
3. Solder the 2 x BC547.
4. Solder the 2 x metal shaft pots.
5. Solder the 12 x sockets. Use the panel to ensure these line up nicely. You can use cut
off resistor legs to make the ground connections.
6. Cut female headers to size and solder them into place. Make sure that they stick out
of the bottom of the PCB.
7. Solder the 4 x plastic shaft pots
8. Solder the 6 x LEDs. Use the panel to ensure that these line up nicely
Bolt the metal shaft pots and the sockets to the panel using their nuts and washers. Pop the
knobs on the pots and the caps on the sliders. Looks nice huh?
Calibration

1. There is nothing to calibrate on this module –cool!
2. Go forth and divide.
Troubleshooting
Not all DIY builds work first time. The vast majority of build issues are down to soldering
inconsistencies. This is far more likely than a bad IC, for example. The first step of successful
troubleshooting should always be to reflow all soldering to eliminate any dry joints (bad
connections) or solder bridges (short circuits). This is also an opportunity to closely inspect
your work –you might find some unsoldered pads, or an IC not inserted into its socket, for
example. Next steps are to double check all resistor values are correct, and to check
polarities of all diodes, transistors, ICs and electrolytic capacitors. This is not an exhaustive
troubleshooting guide, but should address 95% of build issues.
RDH 02/10/20
http://www.frequencycentral.co.uk/