Cheap Headphone Amp

From geraldo.cc.utexas.edu!cs.utexas.edu!zaphod.mps.ohio-state.edu!moe.ksu.ksu.edu!osuunx.ucc.okstate.edu!constellation!midway.ecn.uoknor.edu!norlin Tue Mar 30 21:26:00 CST 1993
Newsgroups: alt.guitar,alt.guitar.bass,rec.music.makers.guitar,sci.electronics
From: norli–(at)–idway.ecn.uoknor.edu (Norman Lin)
Subject: Incredibly CheapER Headphone Amp
Sender: usene–(at)–onstellation.ecn.uoknor.edu (Usenet Administrator)
Date: Wed, 31 Mar 1993 01:57:46 GMT
Nntp-Posting-Host: midway.ecn.uoknor.edu
Xref: geraldo.cc.utexas.edu alt.guitar:3330 alt.guitar.bass:412 rec.music.makers.guitar:2684 sci.electronics:7895

john–(at)–vnews.tv.tek.com (John Reynolds) writes:

>A previous poster mentioned an LM386 based headphone amplifier. Here’s
>a circuit for one I built last night. I think this is probably the most
>minimal implementation for such a beast.

[circuit eliminated]

I missed the start of this thread, but the cheapest possible guitar amp
(IMHO) is to feed the output of your guitar into the input of a simple
Walkman-type cassette player. Simply take the Walkman apart, locate the
leads going from the cassette head to the circuit board, and attach
the output from the electric guitar to the casette head leads. See
diagram:

Roller Head Guide Head
+——————————–+ +——————————–+
| _/|__||| | | |__| |
|| | /| |
|| | / | 3 wires coming|
| O O | | / | off head |
|| | left gnd right |
|| ||
|| | Connect to electric |
|| | guitar output |
+——————————–+ +——————————–+

Front view of walkman Back (circuit board side) view

There will be 3 wires coming off of the tape head connecting somewhere
on the circuit board. The 3 wires are, of course, left channel, right
channel, and ground. Simple poking around with a pair of headphones on
will tell you which line is which. Just tie the ground from your
guitar output to the ground, and the signal to both left and right
channel inputs.

Then, just press PLAY with no tape in the unit, and whatever output
from the guitar will go through the cassette head leads and get
amplified to the headphones. Simple and real cheap; you might need an
attenuating resistor to limit the strength of the signal coming into
the Walkman, but I doubt it with the low levels that an electric guitar
will put out.

Plus, if you pop in a cassette and press play, you will be able to hear
BOTH your electric guitar AND the cassette through your headphones.
Jam along with your favorite tape!

This technique can be used whenever you want an amp out of a cheap
Walkman.

Norman

_______ __ _____ Norman Lin
| | | | norli–(at)–ailhost.ecn.uoknor.edu (preferred)
| | _ |__ | | | nli–(at)–lliant.backbone.uoknor.edu (alt. 1)
| | || | | | nar–(at)–belisk.pillar.com (alt. 2)

 

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