Meowsic Keyboard Output Jack

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Introduction: Meowsic Keyboard Output Jack

About: My name is Randy and I am a Community Manager in these here parts. In a previous life I had founded and run the Instructables Design Studio (RIP) @ Autodesk's Pier 9 Technology Center. I'm also the author ...

When Wilgubeast told me about the supremely annoying Meowsic Keyboard that played cat meows instead of tones, I knew I had to have one. Two days before Christmas I obsessively tracked it down to Target. I then obsessively visited five stores overrun with tumultuous hordes of holiday shoppers until I finally found a store that still had 3 in stock. I snatched one and headed immediately for the register. The checkout clerk, assuming this was surely a gift for a small child, asked if I wanted a bag in which to hide it. I told him it was not necessary. I knew the truth. I was a grown man buying a meowing cat keyboard with the intent of modifying it to play loudly through a distortion pedal during an underground rock show at Frenzy's house in Oakland.

The show went about as well as one might expect it would when someone is playing a meowing cat keyboard through a distortion pedal and a megaphone. We tried people's patience. I think our band may only have 8 lives left.

Nonetheless, I would be remiss if I didn't show you how to add an output jack and volume knob such that you too can use it to make a terrible racket at underground rock shows in Oakland.

Step 1: You Will Need

Go get stuff:

- Meowsic Keyboard
- 100K potentiometer
- 100K resistor
- 10uF capacitor
- SPDT toggle switch
- 1/4" mono jack
- A knob
- shrink tube (or electrical tape)

Step 2: Open

Open up the Meowsic Keyboard and make sure not to lose any of the (many many) screws.

Step 3: Drill

Drill a 3/8" hole in the top of the cat's head for the 1/4" jack.

Drill another 9/32" hole about an inch to the side of the first hole for the potentiometer. To keep the potentiometer from spinning in place, it helpful to drill another 1/8" hold just to the side to catch the little mounting tab.

Finally, drill a 1/4" hole about an inch to the side of the potentiometer for the SPDT switch.

Step 4: Wire It Up

To make the circuit, you will have to cut in half the wire that is connected to the + terminal on the speaker. The half connected to the circuit board will be extended and connect to the center terminal on the switch. The half connected to the speaker will be connected to one of the outer terminals.

The 100K resistor will bridge the outer terminal of the switch to one of the outer terminals of the potentiometer. The other outer terminal of the potentiometer will be connected to ground from the keyboard's power supply.

The positive side of the 10 uF capacitor connects to the center terminal of the potentiometer and bridges to the signal tab on the audio jack (where the negative terminal connects).

The barrel of the jack also connects to ground.

For more info, check out the schematic in the final picture of the series. To learn how to read schematics, check out the Basic Electronics instructable.

Step 5: Clean Up

Glue any loose components in place with hot glue and cover up any exposed electrical connections that may shift about with electrical tape.

Step 6: Case Closed

Refasten all of the screws that you loosened earlier.

Step 7: Knob

Finish it up by affixing a knob to your potentiometer.

Step 8: Rock

Take your keyboard, gather your bandmates, go forth, and make a terrible racket at underground rock shows.

Pictured is the band AIDS Walk (trying to look serious) moments before making a terrible racket.

3 People Made This Project!

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30 Discussions

0
MohiniO
MohiniO

Question 7 months ago on Step 1

Hi randy greetings from the Philippines, I am currently enrolled in your Electronics class because of this 80pesos (1.58usd) Doraemon toy piano I found I was hoping to try learn circuit bending stuff and then found out that this has no bending points and someone in reddit advised to voltage starve and another one advised to just put output to effects. And I did not know where to start and realized needed to learn the basics first. Anyways just getting itchy to do something with this as practice. That is why, I was wondering if it is possible to do this instructable for this piano? If yes, it is possible, then this will be my first electronic project.

If yes Questions:
1. (uses x2 AA batteries) will the values of the potentiometer, resistor and capacitor change?
2. i dont know why but can i replace the speakers if it breaks? (or will the output jack ignore the existing speaker here?)

Thank you for your efforts in teaching these amazing things, been scanning through all your Instructables when i was searching for the Electronics class projects

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0
randofo
randofo

Answer 7 months ago

It should work. The values should theoretically be the same. If it is too quiet, you can try lowering the value of the resistor a little bit (maybe drop it to 47K and see what that does).

You won't break that speaker unless you hit it with a hammer (or something similar).

The potentiometer is basically working as a voltage divider. The resistor is making sure the voltage divider never goes to a value of zero resistance. You can learn about voltage dividers here:
https://www.instructables.com/lesson/Resistors/

The capacitor is filtering out any unwanted noise that might find its way into the audio signal. You likely don't need to worry about that doing anything bad.

0
MohiniO
MohiniO

Reply 7 months ago

I think i broke something it is not working anymore or maybe my soldering is bad? I got the wrong toggle switch (spst instead of spdt) so i had to wait till i got the right one and while waiting i changed the original wires so they are all the same since it was super thin one thin piece inside insulation.

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0
randofo
randofo

Reply 7 months ago

My best guess from the pictures is that you broke the terminal on the speaker where the black wire is connected. I would test it for continuity with a mutlimeter (if you know how). Maybe try adding more solder to bridge the terminal where it seems to have cracked. If that doesn't work, you could possibly try replacing it with another small speaker and seeing if that helps.

0
MohiniO
MohiniO

Reply 7 months ago

Thank you for your time, this is very encouraging, to keep moving forward without getting scared, will work on this today, i got the stuff needed at a local electronics components shop (can buy these stuff per piece here), hehehe, so nervous and excited about this. ))

Will read the resistors lesson right now, just finished reading the switches in your electronics class 2 days ago and had to rest a few days.

0
Mikkel Just
Mikkel Just

Question 1 year ago

Hope this can help you figureout what i did wrong

IMG_20190303_162915.jpg
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Mikkel Just
Mikkel Just

Answer 1 year ago

And from another side

IMG_20190303_165259.jpg
0
randofo
randofo

Reply 1 year ago

I am not sure. Those connections look correct. Maybe the value of the potentiometer is different...?

0
rlpittsjr
rlpittsjr

Question 1 year ago on Step 1

Hoping I can get some help. Trying to get the headphone jack to work. Switch dies work as it cuts the sound from the keyboard speaker but cannot get any sound from the headphone jack.

Have some pics if you have a moment to look.

Thank you.

- Robert

20190616_192733.jpg
0
rlpittsjr
rlpittsjr

Answer 1 year ago

Either I hit the potentiometer or the fact I did no grounding?

20190616_204919.jpg
0
randofo
randofo

Reply 1 year ago

The potentiometer definitely needs to be grounded to a ground connection on the circuit. Also, make sure that you have the polarity correct on the capacitor.

0
Mikkel Just
Mikkel Just

Question 1 year ago on Step 4

Hi i tried to make it but it seems like when i connect the 10uf to the audio Jack theres a flaw the smallest tuch Will make it disconnect the audio im not sure what im doing wrong Hope you can help me out :)

0
rlpittsjr
rlpittsjr

Answer 1 year ago

Seems like we have the same issue. Did you ever get an answer or figure it out?

0
80750
80750

2 years ago

The 8 bit guy did the same thing but with a different output and sound comes from the output and the keyboard itself. It also haves a volume nob.

0
Eduardo73
Eduardo73

5 years ago

My son & I completed this Mod this weekend. Amazing project, thank you so much for sharing your instructions!
http://youtu.be/K3MXyQQN1Jo

0
skinniwini
skinniwini

Reply 3 years ago

nice!!!

0
skinniwini
skinniwini

3 years ago

I saw it on sale in the target for 24.95 locally, I know I will pick one up. want to ask is this hack the output can external record on the computer? Thanks in advance. Thank you for awesome instruction! This will be my first electronic hack.

0
bpope5
bpope5

6 years ago on Introduction

Yet another grown man buying one for himself here. A very useful mod that I plan to do as well. I wish there was a simple way to add midi in and out. That would be pretty crazy, huh?

0
powerman666
powerman666

7 years ago on Introduction

I bought one these toys just to do this. Thanks for the excellent instructable.