Delptronics ThunderBell User Manual
Thunderbell mini kit instructions
ThunderBell Mini Kit Instructions
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Important Information
Thank you for your purchase of the Delptronics ThunderBell Mini Kit!
The most recent version of this document, and the instructions for the ThunderBell Eurorack Module Kit can be
downloaded from
Before you start, please read the Electronic Kit Soldering Tutorial. It contains important and useful information even
for experienced kit builders. If this is your first electronic kit, the best piece of advice we can give is to take your time
and be careful to put the right part in the right place. The tutorial can be downloaded from:
In the instructions that follow, each part type is followed by the PCB outline for that part. Refer to the enclosed
photograph of the completed kit for assistance with part identification and placement.
The PCB is marked with the refdes (reference designator) of each part, not its value. For example R1 refers to
resistor number one and C1 refers to capacitor number one. Once the part value is identified, it is easy to find the
refdes on the PCB.
Some parts must be oriented in a particular way, that is, the correct lead goes in the appropriate hole in the PCB. For
example, electrolytic capacitors are polarized (they have a positive lead and a negative lead). Ceramic capacitors are
not polarized, so it does not matter which of the two leads goes in which of the two holes. In these instructions, the
symbol (±) highlights parts that must be inserted with a particular orientation.
When you are ready to begin, separate the parts by type. Then, when you are ready to solder parts of a particular
type, separate them by value. Compare your parts to the bill of materials, which can be found on the last page of this
document. Make sure no parts are missing. These instructions list the parts in the recommended order of assembly.
In general, the order is shortest to tallest.
This manual is separated into two sections: board-mounted parts, which are soldered directly to the PCB, and off-
board parts which are connected to the PCB via wires.
Using the ThunderBell
Power: The ThunderBell is powered by a 9V battery.
Trigger Button: Press the button to make the bell sound.
Pitch Knob: controls the pitch of the bell.
Decay Knob: controls how long it takes
for the bell’s volume to decay from its maximum level down to silence. The
bell can be re-triggered even while the last bell sound is still decaying.
CV (control voltage) Jack: allows you to control the pitch of the bell with an external analog device, like a
sequencer. It accepts zero to 5V, but has over-voltage protection. When a plug is inserted into the CV Jack, the pitch
knob is ignored.
Trigger Jack: allows you to trigger the bell sound using an external analog device like a sequencer. It accepts a 5 to
15 volt positive trigger or gate signal. The trigger button can still be used even when a plug is inserted into the Trigger
Jack.
Output Jack: Plug a ¼ mono cable into the output jack and plug the other end of the cable into your amplifier or
mixer. When a mono plug is inserted, the bell is powered on. A stereo plug will not work.