Ramsey Electronics MX-5, Assembly And Instruction Manual

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MX-5 Page 11
ˆ 20. Now it is time to install U1, the LF347 quad opamp. Notice how on one
end of the IC there is a notch, dimple or dot indicating pin one of the IC.
You will need to align it with the notch as shown in the parts layout
diagram. Make sure all 14 pins are through the board before soldering,
and that none are bent under the IC.
ˆ 21. Install R19, a 1M ohm resistor (watch out! 1,000,000 ohms!) (brown-
black-green).
ˆ 22. Install R28, a 1M ohm resistor (brown-black-green).
ˆ 23. For R27, you will need to decide what type of microphone you wish to
use. If you plan on using a store bought microphone, you do not need to
install this resistor. If you are planning on making your own microphone as
shown later in this manual, the resistor is used to power an electorate
microphone. If in doubt, install it anyway, it will case no harm to a
microphone and it doesn’t reduce sound quality. R27 is a 47K ohm
resistor (yellow-violet-orange).
ˆ
24. Install JMP1 using a scrap piece of component lead. Jumpers act as
“bridges” over other circuit paths so that signal lengths on the board are
as short as possible.
ˆ 25. Install JMP2 using another scrap piece of component lead.
ˆ 26. Install R15, a 10K ohm resistor (brown-black-orange).
ˆ 27. Install R17, a 10K ohm resistor (brown-black-orange).
We are done installing the low profile components and are moving on to the
high profile components. Be aware of orientation of the parts when installing
them, many do not like being installed backwards and will prevent you from
having an operational kit when you are done. Before continuing though we
want to check all of your solder joints up to this point for cold solder joints or
solder bridges. If in doubt, re-heat the solder joint adding a little more new
solder.
ˆ 28. Install C1, a 10uF electrolytic capacitor. Notice this is the first
capacitor of this type. You want to be sure that you pay close attention to
the polarity markings on this part. In most cases the negative (-) side is
marked on the capacitor, while the positive side (+) is marked on the parts
layout. If you fail to mount this component correctly, the part can fail as
well as prevent proper operation of your project. We will be installing many
more of these later in the project so be sure and remember this!
ˆ 29. Install C4, a 10uF electrolytic capacitor. Again note polarity!
ˆ 30. Install C2, another 10uF electrolytic capacitor.