Private Amp From a Old Personal Cassette Player





Introduction: Private Amp From a Old Personal Cassette Player

About: i am a photolab technician and an incurable packrat. i have made swords ,chainmail, crossbows.cameras,bike trailers,kayaks,guitars{slide and electric},knives,various film winders and vacum easels for the ph...

hi folks today im going to help all our guitar playing friends improve their relationships with neighbours and or family.
no im not going to personally give them each 50 bucks to leave you alone what im going to do is supply you with the knowhow to make a small guitar amp that will only annoy you {well it may annoy you if you play bad like me}.
best of all it only takes about 10 minutes to do

Step 1: What Yer Gonna Need

ok to do this your going to need
1. old personal casstte player that you dont mind destroying
2. guitar cord that you dont mind cutting an end off{ we all have one that only works when you bend it}
3. a fine soldering iron and rosincore solder{you can sharpen the point of a cheap pencil iron}
4. a set of head phones
5. an electric guitar or acoustic with a pickup installed

Step 2: Theroy {sort Of}

ok now we all know that an electric guitar generates a very weak current when you strum the strings.
the playback head on a cassette player works on a similar principle {it generates an even weaker current when a magnetized tape is passed over the reading head}.
so if we take the leads from an electric guitar and solder them to the wires coming out of the cassette players playback head then press play on the player then we will hear the guitar in our headphones.
my theory actually worked (too well) much to my surprise .i had invisioned playing the tape and playing along with it too but the guitar was way too loud.
i know just turn down the volume knob on the guitar and i can fix that right?
not on my guitar anyway dirty pots mean that it only works in one or two places.
as a bonus this particular player had a 3 channel equalizer built in .
when its turned down on all of them the sound is nearly normal turn them up and it distorts like crazy.

Step 3: Where to Attach the Wires

what you need to do next is figure out which end of the cord is bad . i just cut mine in the middle and tested with a volt/ohlm meter and tossed the twitchy end.
then strip back the insulation until you have at least 1/4 inch of bare copper for both conductors{if your using a stereo cord with three conductors you will have to solder the two insulated wires together}.
at this point you need to solder the wires onto the play head leads.
the braid{ground wire} will attach to the biggest contact on the play head, the wire in the center insulation will need to connect to both of the smaller contacts or you will have a mono amp.
it doesnt matter much if you get this backwards cause it will still work.
i will assume that most of you are familiar with the finer points of soldering if not there are several good tutorials out there on how too{i think there even some instructables on the subject}
as you can see i had to pluck out the rewind knob to make an access hole.
a better way than how i did it would be to trace the wires from the play head to where it connects to the circuit board inside .you dont even need to leave the play head connected.

Step 4: Conclusion

since i made this i have seen several variations on a similar theme. most of them are neater than this job .
remember when selecting a player for this try to pick on one that doesnt work right this one had tape transport issues and would slow down and speed up unpredictably.
i know they aren`t antiques yet but they are a vanished technology and getting rarer all the time.
thanks for looking and if you do one of these and make a better job (or not) of it please post it.


attached {i hope } you will find 4 samples recorded from this mini amp
please note i just did extremes as a sample to let you get a feel for the range available .
im sure somewhere in the middle will sound better.
my apologies for the crappy playing



    • BBQ Showdown Challenge

      BBQ Showdown Challenge
    • Clocks Contest

      Clocks Contest
    • Water Contest

      Water Contest

    56 Discussions

    did this to an old stereo, with a record function, so now i have a line out from my cd player, as well as a dirty guitar/ bass input,

    excellent design buddy :)

    I would reccommend adding a resistor between the guitar and tape player, as the guitar input is stronger than what the tape player is designed for. Also, Disconect the motors from the circuit, and leave the conecctions without anything connected, as this will conserve battery power, and stop the clicking that some people experience.

    Nicely done!! Simple and reusing old technology that still works. There are many old tape players to be had at flea markets and yard sales. One recommendation I would have is to disconnect the motor or remove it for a robotic experiment. The reason is that it draws juice and can add noise to the audio circuit. Some players need the play button to be pushed for the amp turn on. Party On Bill and Ted!!

    2 replies

    i have the player rigged so you can run a tape and play at the same time. something to play along with. but you can remove or disconnect it on most players as long as the juice for the rest of the player is not routed through the motor circuit for simplicitys sake{never know with some of the awful players that were out there} thanks for the nice comment

    anyways, the cheapo earphones are just piezo buzzers (the good ones, you can get strong magnets) and you can just put them (the piezo buzzers) on the soundboard, one under the bridge, one where the fretboard joins the soundboard. then just connectt the negative terminals of the piezo together and each +ve contact to the signal wires of the tape reader. lol stereo. AND they sound better than joining the signal wires 2gether

    1 reply

    took me some time to get a, cheapo earphone thaat uses a piezo buzzer.....

    I've been trying to make one of this out of a not so old walkman. I think it should work, but the play head is way different than this one so I don't have a clue of where to solder the wires. Plus, I want to solder it to a plug jack instead of directly to the wires so I don't have to tear my one and only cable. I attach the picture of the head. Any help wil be really, really, reaaaaaally appreciated

    6 replies

    hey that one is different. your best bet would be to make up a set of probes out of an old guitar cord and while running the tape player{and listening to it} touch the probes to different sets of wires. most likely you will find the little one in the center is your ground and the ones to either side are your left and right channels. if you want the sound to come out of both sides of your headphones you will want to gang those{left and right groups} together .then solder them to one of the side of the jack and solder the center contact to the other side of the jack. hope this helps.

    The thing is the head has four contacts on each side plus the one in the center. How should I solder the wires???? Will it work if I solder the wires horizontally so the wire touches the four contacts???? Thanx for the help!!!!

    Unlike PyromanicDaniel I think it's a reverseplay walkman, the two extra wires are for the other side of the casette. Prolly it doesn't matter wich pair you use.

    that seems to be the case. but probe the contacts first to be sure. my guess is you will want all the contacts from both sides feeding to one wire of the pair from your guitar cord and the single one in the middle feeding to the other. good luck.

    I imagine that the player in question is one that can record also and the extra wires are for recording to the tape.

    I saw an instructable on using a old folk listening device for a headphone amp and I thought to use an ancient tape deck that one would have laying around collecting dust and here you have already done it for a guitar amp. Very Nice.

    You could use a variable resistor in line with the guitar inputs to change the volume of just the guitar down to the tape deck level. be sure to get a audio pot as they are logarithmically adjusted (meaning that it is not a linear resistance but instead is exponentially increased to match our hearing scale)

    1 reply

    im glad you like it.
    actually the first improvised amp i ever tried was an old stereo that had an input for a magnetic cartridge turntable.
    it was kind of hard on the speakers but it worked well enough.
    also most electric guitars already have a volume pot built right in so another is kind of me. lol

    you might have done something wrong with the soldering part...or somethings wrong with the player your using...try tracing where or what you might see whats wrong with it....

    im just wondering if some one can teach me or can some one show me how to make a amplifier out of lm324n ic???or if some one can make an instructable about amplifier out of old cd player....

    thankz...ill be waiting for some answers.....

    I finally made it and it works just fine but the volume is pretty low even when having both the player and the guitar at max volume. Also how below guy says there is a ffffffffffffffff sound when playing. Could this things be due to wrong soldering or is just the way it usually goes

    1 reply

    mine is very loud. perhaps your not connected to both the left and right connections on one side and the centre on the other. if you get left or right soldered with the center you may get what your describing there. how you need to solder it is identify the ground wire on the head(Thats center channel on stereo) then group the other 2 wires together{left and right}then solder the 2 leads from the guitar to the wires going to the head. also maybe the polarity is wrong . try changing the wires around. hope this helps

    This is a good Instructable, but I found that when wired to the tape heads, the sound quality was DREADFUL. i would recommend it is wired as a line in straight to the amp in the player.