CGS738 Mangler
ELBY Designs - Laurie Biddulph
9 Follan Close, Kariong, NSW 2250, Australia
2 of 4
Construction of the
requires the assembly of 1 board:-
Column 1 - CGS738 PCB (
)
Constructors should refer to the
for any specific comments regarding
the board assemblies, the
for the current value of all components and
for general PCB assembly guidelines.
1. Fit all components to the board except the LED, jacks and headers,
2. Mount and solder the jacks on to the Carrier Boards,
3. Position the 2x Jack Carrier assemblies J101 and J103 on to the PCB and
offer the assembly up to the panel.
4. Offer the assembly up to the front panel and use the relevant nuts to hold the
assembly in place. You will need to manoeuvre the jack/Carrier assemblies in
to place as this is done. When tightening the nuts on the jacks, try to keep
the boards parallel to the main board.
5. Solder the Carrier Boards in to place – this can be done from the topside as
the holes are plated.
6. Using a pair of fine nose pliers, bend the legs of the LEDs to approximately
50° starting at about 5mm from the body of the LED and taking note of the
orientation of the LED to the PCB. Slip the legs in to place on the PCB while
also feeding the LED head in to the panel hole. When completed, the LED
legs should clear the switch beneath it and should run parallel to each other
down to the PCB
7. Flip the assembly over and solder the LEDs in to place.
8. Make sure all nuts are tight. Do not over-tighten the jack nuts as this may
strip the thread – I like to do the jack nuts up finger tight and then use a
10.5mm open-ended spanner to tighten the nut until one of the flats is
parallel to the bottom edge of the panel. A similar approach is used with the
switch nut. Pot nuts should be done up tighter as they provide the main
support for the PCB.
CALIBRATION
Two procedures are offered for calibrating the Mangler. The first only requires a multi-meter while the second
requires an oscilloscope.
1) Calibrating with a multi-meter
a. Power the module with nothing connected to the inputs.
b. Set the K1-K2 switch to its centre position.
c. Adjust P105 until the voltage on U101 Pin7
= +2.5 volts
d. Adjust P104 (DOWN Trim) until the DOWN
output reads 0.0 volts.
e. Connect a positive DC voltage of 5 volts or
more to IN 1.
f. Starting with POT IN 1 fully counter
clockwise, turn clockwise it until the LED
lights, then back off again until it just
extinguishes.
g. Adjust P103 (UP Trim) until the UP output
reads 5.0 volts.