# Meowsic Cat Piano Line Out
## Overview
https://youtu.be/a1ofn3EhtS4
The Meowsic cat piano is amazing, but a bit too quiet. I knew I had to give it a line out so it could be heard meow-meow-meowing far and wide, and enhance the sounds with guitar effects pedals!
This mod is based on the circuit found [here](https://www.instructables.com/Meow-Keyboard-Output-Jack/), with some adjustments to parts and techniques.
Don't have a Meowsic Cat Piano? That's OK, this can also be a helpful guide for anyone wanting to add a line out to other sound toys.
## Parts
### Meowsic Cat Piano
Made by [B. Toys](https://mybtoys.com/shop/meowsic/), available at Target and other resellers online.
Select one of the following three audio connectors depending on whether you will use the project with a 1/8" / 3.5mm or 1/4" plug.
### Panel Mount 1/8" / 3.5mm TRS Audio Jack Connector
[Panel Mount 1/8" / 3.5mm TRS Audio Jack Connector](https://www.adafruit.com/product/3692)
What _is_ this TRS bit? **T** urtle **R** ock **S** tudios? **T** ransmission **R** aman **S** pectroscopy? Not quite, more...
In Stock
[Buy Now](https://www.adafruit.com/product/3692)
[Related Guides to the Product](https://learn.adafruit.com/products/3692/guides)
### Panel Mount 1/8" / 3.5mm Mono Connector
[Panel Mount 1/8" / 3.5mm Mono Connector](https://www.adafruit.com/product/4361)
Pipe audio in or out of your project with this very handy panel mount audio jack. It's a mono jack with a disconnect pin so you'll get a ground sleeve pin, a left tip pin and a pin that will be disconnected when a jack is inserted. You can use any **3.5mm audio cable**...
In Stock
[Buy Now](https://www.adafruit.com/product/4361)
[Related Guides to the Product](https://learn.adafruit.com/products/4361/guides)
### Part: 1/4" Panel Mount Jack
quantity: 1
6.35mm (0.250", 1/4") - Headphone Phone Jack Mono Connector Solder Lug
[1/4" Panel Mount Jack](https://www.digikey.com/en/products/detail/cliff-electronic-components-ltd/CL1130A/25603868)
### Panel Mount 100K potentiometer (Breadboard Friendly)
[Panel Mount 100K potentiometer (Breadboard Friendly)](https://www.adafruit.com/product/1831)
This potentiometer is a two-in-one, good in a breadboard or with a panel. It's a fairly standard linear taper 100K ohm potentiometer, with a grippy shaft. It's smooth and easy to turn, but not so loose that it will shift on its own. We like this one because the legs are 0.2" apart...
Out of Stock
[Buy Now](https://www.adafruit.com/product/1831)
[Related Guides to the Product](https://learn.adafruit.com/products/1831/guides)
### Mini Panel Mount SPDT Toggle Switch
[Mini Panel Mount SPDT Toggle Switch](https://www.adafruit.com/product/3221)
This or that, one or the other, perhaps or perhaps not! So hard to make decisions these days without feeling like you're just going back and forth constantly. Deciding whether or not to use this mini toggle switch? That's the easiest decision you'll make all day!
This...
In Stock
[Buy Now](https://www.adafruit.com/product/3221)
[Related Guides to the Product](https://learn.adafruit.com/products/3221/guides)
### Through-Hole Resistors - 100K ohm 5% 1/4W - Pack of 25
[Through-Hole Resistors - 100K ohm 5% 1/4W - Pack of 25](https://www.adafruit.com/product/2787)
ΩMG! You're not going to be able to resist these handy resistor packs! Well, axially, they do all of the resisting for you!
This is a **25 Pack of 100K Ω Resistors.** More specifically, they are **carbon film** , through-hole...
In Stock
[Buy Now](https://www.adafruit.com/product/2787)
[Related Guides to the Product](https://learn.adafruit.com/products/2787/guides)
### 10uF 50V Electrolytic Capacitors - Pack of 10
[10uF 50V Electrolytic Capacitors - Pack of 10](https://www.adafruit.com/product/2195)
We like capacitors so much we made a [kids' show about them.](https://www.youtube.com/watch?v=sy_G1oYRQmM) They're super handy and it's really helpful to have a variety lying around to pick and choose from.
In Stock
[Buy Now](https://www.adafruit.com/product/2195)
[Related Guides to the Product](https://learn.adafruit.com/products/2195/guides)
### Anodized Aluminum Machined Knob - Black - 20mm Diameter
[Anodized Aluminum Machined Knob - Black - 20mm Diameter](https://www.adafruit.com/product/5527)
These compact and luxurious machined knobs look fantastic and have a nice feel, a perfect way to upgrade your rotary encoder or potentiometer. We hand-selected the best knobs for your project in different...
In Stock
[Buy Now](https://www.adafruit.com/product/5527)
[Related Guides to the Product](https://learn.adafruit.com/products/5527/guides)
### Adafruit Perma-Proto Mint Tin Size Breadboard PCB
[Adafruit Perma-Proto Mint Tin Size Breadboard PCB](https://www.adafruit.com/product/723)
Making a project that will fit into an "Altoids" Mint Tin? Put down that PCB shear and pick up a Perma-Proto in the new exciting minty shape!
Customers have asked us to carry basic perf-board, but we never liked the look of most basic perf: its always crummy quality, with...
In Stock
[Buy Now](https://www.adafruit.com/product/723)
[Related Guides to the Product](https://learn.adafruit.com/products/723/guides)
# Meowsic Cat Piano Line Out
## Mod the Meowsic
## The Modifications
The audio output of the Meowsic PCB runs to the on-board speaker. This project intercepts that signal and brings it down to a suitable level for use with guitar pedals and amps.
This includes adding a 100K Ω potentiometer for signal attenuation, 100K Ω resistor to limit current, and a 10µF capacitor is used to remove the DC offset so the audio signal is centered around 0V.
You'll also add a dual-throw switch that lets you pick between the original on-board speaker and the line output.
## Open the Cat Piano
Remove all 21 of the screws from the back of the piano to open it up.
Open the back from the top, being mindful not to pull on the wires that connect the battery box to the board.
## Audio Out
You'll intercept the audio output of the Meowsic PCB to run through the switch, attenuator, and output jack you'll be adding.
This red wire running to the speaker is the audio out line, you can desolder this wire from the speaker now.
## Ground
You'll solder the ground wire for the added circuit to this center common pin on the Meowsic on/off switch.
## Parts Sub-Assemblies
### Selector Switch
Solder three wires to the SPDT switch -- you'll connect the common line to the audio output of the Meowsic PCB, one outer leg back to the speaker, and the other leg to the resistor-attenuator-capacitor output circuit.
Optionally, you can use a guitar pedal-style 3PDT stomp switch here, [such as this one](https://lovemyswitches.com/3pdt-latched-foot-switch-solder-lugs-old-blood-red/), seen in the remaining photos in this guide.
### Attenuator
It's helpful to have a way to adjust the output level when interfacing with other gear. You'll used a 100KΩ potentiometer as a signal attenuator. You can wire it up as shown, with ground on the left leg, the incoming audio signal (post switch and current limiting resistor) on the right leg, and the attenuated output audio signal on the center wiper leg.
### Output Jack
You have a few options for the output jack. A typical guitar pedal/amp setup will use a 1/4" mono jack.
You can also move down to a very similar 1/8" (a.k.a., 3.5mm) mono jack, shown here. Solder the ground wire to the sleeve contact (the shorter one). Solder the signal wire to the tip contact (the longer one).
One other option, if you plan to plug into more typical 3.5mm jacks on powered speakers, is to use a 3.5mm stereo jack with both of the tip and ring legs soldered to the signal wire, and sleeve to ground.
Primary: Be sure you select the jack type you need for your gear, either 1/4" (guitar size) or 1/4" / 3.5mm (headphone and patch cable size).
### Circuit
You can use a small PermaProto board to make all of the connections and add the 100KΩ resistor and 10µF capacitor to the circuit as shown here and in the Fritzing diagram and schematic.
Note: the two thin black wires in the first photo are unnecessary -- I soldered in both a 1/4" jack and 3.5mm jack, hence the extra connection.
Use an existing screw from the Stop button to mount the board in the case.
Warning:
## Assembly
Use a drill and appropriate sized bits (or a hole reamer) to make holes in the Meowsic case for the switch, knob, and jack.
### Audio Jack Mounting
Mark and drill a hole for your chosen audio jack.
### Potentiometer Mounting
Mark and drill a hole for your potentiometer. You'll also need to make a small secondary hold for the tab that prevents the body of the potentiometer from rotating.
You can find this second hole's position by putting the pot in from the outside and marking the cat's paint with some pressure on the small tab.
### Knob
Screw on the potentiometer nut, then add the knob of your choice to the potentiometer shaft.
Here's a look at all the mods in place.
## Play!
Plug your guitar cable into the cat, add a pedal or two, and crank that amp. It's cat piano time.
https://youtu.be/a1ofn3EhtS4
## Featured Products
### Panel Mount 1/8" / 3.5mm TRS Audio Jack Connector
[Panel Mount 1/8" / 3.5mm TRS Audio Jack Connector](https://www.adafruit.com/product/3692)
What _is_ this TRS bit? **T** urtle **R** ock **S** tudios? **T** ransmission **R** aman **S** pectroscopy? Not quite, more...
In Stock
[Buy Now](https://www.adafruit.com/product/3692)
[Related Guides to the Product](https://learn.adafruit.com/products/3692/guides)
### Panel Mount 100K potentiometer (Breadboard Friendly)
[Panel Mount 100K potentiometer (Breadboard Friendly)](https://www.adafruit.com/product/1831)
This potentiometer is a two-in-one, good in a breadboard or with a panel. It's a fairly standard linear taper 100K ohm potentiometer, with a grippy shaft. It's smooth and easy to turn, but not so loose that it will shift on its own. We like this one because the legs are 0.2" apart...
Out of Stock
[Buy Now](https://www.adafruit.com/product/1831)
[Related Guides to the Product](https://learn.adafruit.com/products/1831/guides)
### Mini Panel Mount SPDT Toggle Switch
[Mini Panel Mount SPDT Toggle Switch](https://www.adafruit.com/product/3221)
This or that, one or the other, perhaps or perhaps not! So hard to make decisions these days without feeling like you're just going back and forth constantly. Deciding whether or not to use this mini toggle switch? That's the easiest decision you'll make all day!
This...
In Stock
[Buy Now](https://www.adafruit.com/product/3221)
[Related Guides to the Product](https://learn.adafruit.com/products/3221/guides)
### Through-Hole Resistors - 100K ohm 5% 1/4W - Pack of 25
[Through-Hole Resistors - 100K ohm 5% 1/4W - Pack of 25](https://www.adafruit.com/product/2787)
ΩMG! You're not going to be able to resist these handy resistor packs! Well, axially, they do all of the resisting for you!
This is a **25 Pack of 100K Ω Resistors.** More specifically, they are **carbon film** , through-hole...
In Stock
[Buy Now](https://www.adafruit.com/product/2787)
[Related Guides to the Product](https://learn.adafruit.com/products/2787/guides)
### 10uF 50V Electrolytic Capacitors - Pack of 10
[10uF 50V Electrolytic Capacitors - Pack of 10](https://www.adafruit.com/product/2195)
We like capacitors so much we made a [kids' show about them.](https://www.youtube.com/watch?v=sy_G1oYRQmM) They're super handy and it's really helpful to have a variety lying around to pick and choose from.
In Stock
[Buy Now](https://www.adafruit.com/product/2195)
[Related Guides to the Product](https://learn.adafruit.com/products/2195/guides)
### Anodized Aluminum Machined Knob - Black - 20mm Diameter
[Anodized Aluminum Machined Knob - Black - 20mm Diameter](https://www.adafruit.com/product/5527)
These compact and luxurious machined knobs look fantastic and have a nice feel, a perfect way to upgrade your rotary encoder or potentiometer. We hand-selected the best knobs for your project in different...
In Stock
[Buy Now](https://www.adafruit.com/product/5527)
[Related Guides to the Product](https://learn.adafruit.com/products/5527/guides)
### Panel Mount 1/8" / 3.5mm Mono Connector
[Panel Mount 1/8" / 3.5mm Mono Connector](https://www.adafruit.com/product/4361)
Pipe audio in or out of your project with this very handy panel mount audio jack. It's a mono jack with a disconnect pin so you'll get a ground sleeve pin, a left tip pin and a pin that will be disconnected when a jack is inserted. You can use any **3.5mm audio cable**...
In Stock
[Buy Now](https://www.adafruit.com/product/4361)
[Related Guides to the Product](https://learn.adafruit.com/products/4361/guides)
### Adafruit Perma-Proto Mint Tin Size Breadboard PCB
[Adafruit Perma-Proto Mint Tin Size Breadboard PCB](https://www.adafruit.com/product/723)
Making a project that will fit into an "Altoids" Mint Tin? Put down that PCB shear and pick up a Perma-Proto in the new exciting minty shape!
Customers have asked us to carry basic perf-board, but we never liked the look of most basic perf: its always crummy quality, with...
In Stock
[Buy Now](https://www.adafruit.com/product/723)
[Related Guides to the Product](https://learn.adafruit.com/products/723/guides)
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