Simple stereo 3-band audio equaliser kit

Name: Simple stereo 3-band audio equaliser kit
SKU: 7885
Price: 20.00 USD
Availability: Discontinued

The circuit contains 2-ch 3-band equaliser circuit with Lipo battery charing circuit. Very easy to use!

Designed by microwavemont in Japan

Product Retired

This product is no longer available for sale.

The seller may be offering an improved version or it may be hanging out on the beach, enjoying the retired life.

While you're here, check out these other awesome products for sale!

More "Hackaday" Related Products

Sale

FlippenHeimer -Geiger Counter for the Flipper Zero

Erwin Ried

$22.49 $44.99

Louder ESP32

Sonocotta

$24.00

USB-C for PS4 controller

Marius Heier

$10.00

duckyPad: Do-It-All Mechanical Macropad

dekuNukem

$64.99

Simple stereo 3-band audio equaliser kit 1

Simple stereo 3-band audio equaliser kit 2

Simple stereo 3-band audio equaliser kit 3

Simple stereo 3-band audio equaliser kit 4

Simple stereo 3-band audio equaliser kit 5

On Dec. 15, 2025, my tindie store "micowavemont" trying restarting! Stay tuned!

The circuit contains 2-ch 3-band equaliser circuit with Lipo battery charing circuit. Very easy to use!

This is a full parts kit contains everything except for LiPo battery cell. LiPo battery is prohibited for sending in parcel by international parcel regulation so please find it at your local reseller…

What is it?

2-ch (stereo) 3-band audio equaliser with Lipo battery charging circuit. This circuit is driven by 3.7 V single voltage from LiPo battery. Input and output are general 3.5 mm stereo jack.

Why did you make it?

Listening music sometimes requires sound manipulation,for example, at bed side before sleep too much high-tone is something annoying but soft (bass boost, high tone reduced) tone music is quite pleasant. Recent digital audio player have built-in digital audio equaliser but "manipulation by what we can see and touch" provides more "joy of operation". In addition, I hate making "garbage of wasted battery" or "external battery charging handling" so battery charging circuit is embedded.

What makes it special?

LiPo battery charger embedded and just connecting (mini) USB cable connecting to PC is enough for charging. During charging RED led will turns on and after full charge, GREEN LED will turn on!
All of parts are "lead-axial" and easy for soldering
For low (3.7 V) and single voltage by single cell Lipo, Operational amplifier is carefully selected (JRC NJM2115 )
Just connecting your music player for input, headphone for output enables wonderful music experience!

General Line-level driving is NOT suitable for this device. For usage, please connect "headphone terminal out" of your device, such as cell-phone and iPod, iPad, ....

As is in picture, surface mount parts (USB terminal and TP4057) are pre-soldered for your convenient. All you will need to solder is "lead-axial components"