Beginner's capacitor question
trixter at oldskool.org
Mon Apr 14 20:03:17 CDT 2008
I have a need to record the output of a (5150) speaker. Although I
thought that I could just alligator-clip a positive lead to one speaker
terminal and the negative to the case/ground, the output was decidedly
"buzzy" (I assumed it was too "hot" and overmodulating). I routed it
into a mixer and turned it down (speaker is 5v, not sure what line input
is) but it still didn't sound right.
I found some old directions on hooking up a PC speaker to a line input,
and was confused by the use of a capacitor -- I would have thought that
a resistor would have been more appropriate, to limit the signal
perhaps? In any case, here are the instructions, followed by my question:
- 6' to 12' shielded cable with RCA plug (male) on one end
- Two alligator clips
- One 4.7 uf capacitor
1. Connect one alligator clip to the shielded portion of the cable.
2. Connect the (-) minus side of the capacitor to the center conductor
of the cable and then connect the (+) side of the capacitor to the
second alligator clip.
3. Attach the clip with the capacitor to one of the wires going to your
computer's speaker. Attach the other clip to the metal case (ground)
somewhere (such as a screw or bolt connection).
4. Connect the RCA plug to the auxiliary input on your stereo system or
While I have read the wikipedia entry on capacitors, I'm missing
something obvious. My question: Why the 4.7uf capacitor? Does it
serve to limit the signal? Reduce it's voltage? (or increase it?)
Filter the signal in some way?
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
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