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Chaos Computer Club 1997 February
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habi1
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hb1_197.txt
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1997-02-28
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90 lines
2600 ~o~ TO 6~' 1'~ SU"LY
IN | ~ TO "`Jl~7« V.3vr,lt ~ _
~; ~DIO 2
~L~
_~
~1
T° ~THER
au7~o~s
NOTES
This mixer-ampllfier uses 24 diodes to
produce 12 separate tone pairs without
mixing them at their source. Each
diode is silicon, low current, and the
pair should be matched if possible. A
single pure tone needs no diodes, of
course.
A telephone earpiece is a perfec~, low
cost speaker for this unit, and has the
added advantage of coupling tightly with
a telephone mouthp~ece if yon want to
play this instrument to your friends,
over the phone.
A 50K ohm trimmer tunes each oscillator.
All parts in this project are 10% or
better tolerance, but the capacitors
should be drift-free types(mylar, epoxy,
or mica), or else the oscillators will
detune easily.
Two bstteries are recommended for ease
of construction and stability of tone.
~STO,S - 10°~
DI0055 -~7`UE.
5~ SiCN4L
a~no~s ' SPSt ~.
AMp 7~.~ S8~
*276B016
TE~
EARPIECE
_ _ ─_─ .
, l
L
t10
~60~. ~
is lo~T . ~ MFO,
This simple mlzer and amplif ier can
be used in the e. lectranic organ de -
scribed last iseue . 1 ) Power to the
speal~er will be lost at low frequen-
cies if a sultable enc lo~ure is not
used. A small metal 3r plastic box
is fine. The box can, of c~urse,
contain the rest of the parts. Tones
can be f~und for sultable notes ln
any sonnd engineering manual.
2) {f played into the phone [or any
reason, the speaker should be lined
with a circle of f~am to form a good
seal that is held tightly to the
mout hp ie ce .
ylpp~re bOred °
WestlOdnl ke to
ni gdh tt~ 2 4 5 - 1 5 0 0
1' '1
~i