Quick and dirty mod to a $20 cassette player to control speed & play forward & reverse with a switch

I show you how to take a cheap cassette tape player that's glutting the market now that makes for an simple modification to play both backwards and forwards. I've done a couple of these and it takes an hour or two - and that includes playing with it afterwards. It does require soldering a couple of points on the cassette PCB, but nothing too fiddly.
I have a shorter version for those who only want to do the forward/backward playing here:
• Quick and Dirty Revers...
Honestly, it took me longer to do the video than the mod!
To find the cheapest version, go to Amazon and search for
'usb cassette mp3 player'
then sort 'from low to high'
all of the same model has the silver band around the middle - just different outside graphics.
Requires only a tiny phillips screwdriver, a soldering iron and something to cut plastic. Maybe a small file and a spudger for opening the case.

[@bonistik]

Hope to see more modding and circuit bending tutorials like this!

[@zenSutherland]

Thanks, Bonistik! I hope to make them. :)

[@emaglott]

Nice work Zen! I am impressed how slow it can run on the PWM controller without stalling.

[@zenSutherland]

Thanks! That's one of the things i love about the PWM - besides, when i use potentiometers i can never get the adjustment to feel right. :/

[@timcowie]

Thanks for the great video! I completed mine last night. The switch is super cool - i make loops on a 4 track so i am going to use it to switch between tracks 1+2 and 3+4. I just popped a 10k pot into where the speed trimmer is for speed control which adds a bit of control but not as good as yours. Think I'm going to hack another with the PWM controller now.

[@rafaelaragonDJ]

I'm having the same idea, and I'm wondering if it's possible to mod / change the "reverse" switch, so we can have the option of having 1/2 AND 3/4 instead of (or in addition to) 1/2 OR 3/4. You can split the stereo output into 2x mono with volume control pots on each out, and then having a proper 4 track player.

[@rafaelaragonDJ]

since I didn't have a PWM controler, I put a 5k pot replacing the speed controlling trim pot, plus another one between V+/- and Motor +/- . It functions as a "brake / super slow" control. This way by tweaking both pots you can get in super slow mode with more precision.

[@fflynnful]

There is already a speed control built in, why not just connect it to an external potentiometer?

[@back4onemore]

Any way to put a auto reverse on one if it doesn’t have it?

[@MegaDbase]

Hi, have you tried using a usb stick to record the playback ?

[@butter3688]

Hello! I recently did this mod and the functions worked perfectly except for a pretty loud ringing at 10khz. Do you have any suggestions to fix that? Thanks love this design!

[@zenSutherland]

I don't know where that 10khz is coming from, but maybe look to using a resistor/capacitor on the line to filter out that range? It sounds like there could be some tone and volume loss tho.

[@gagnolino]

Hi, nice tutorial! I got the same cassette player and bad results in modifyng its speed using normal potentiometers, even if with different resistance values. Could you suggest me the type of PWM controller you use in the video? Thank you in advance

[@zenSutherland]

Sure, Giuseppe. I used the very cheap ones from Amazon: www.amazon.com/gp/product/B09NN4YMHC The only drawback was the janky screw-in terminals. Next time i'll desolder those and run wires to the PWM board.

[@gagnolino]

@@zenSutherland thank you, I have ordered a pwm and I will try soon. But what if I want to use the usb or dc charger instead of batteries? Should I solder the wires to some different point on the pcb compared to where you soldered using batteries?

[@zenSutherland]

@@gagnolino Yes, i used the batteries to power the PWM module, so you will need to take a voltmeter to find power for the module as neither USB nor a dc charger feeds into the batteries. Those points on the PCB will probably be pretty close to where the battery wires connect. I hope this helps!

[@howva]

Hi Zen thanks for this video! I have tried this method and it works but I don't get the same range in the slow down as you do I get much more speed up range, don't really know what the issue is! I like how you used the same batteries to power the board very smart

[@zenSutherland]

I don't know what the issue might be, sorry.

[@rafaelaragonDJ]

@@zenSutherland maybe different PMW controller for different voltage/values.. ?

[@Stoney-Jacksman]

Very cool. Is this possible with tempo instead of speed?

[@sage_and_pinestudios5999]

Mechanical speed and tempo are linked in this situation.When the tape speed is increased or decreased there is technically a change of tempo but it is also linked to pitch. Tempo of the recorded track is determined at time of recording if that's what you are referencing. To increase tempo without affecting pitch, you'd need some effect to be applied to the audio like a pitch shifter/re-sample before routing the audio out. So it could technically be done....

[@user-fy6sz8cy8u]

Cheap mp3 speaker