CopperSound Cir-Kit Breadboard Bundle 3-Band EQ

A "Baxandall" EQ: the classic that teaches you to listen (and understand)

The 3-Band EQ from the Cir-Kit range is based on the spirit of Baxandall equalizers, known for their natural behavior and effectiveness when you want to balance a sound without making it artificial. In practice, it's one of the best playgrounds for progressing in DIY: you immediately hear the impact of an adjustment and quickly understand the role of the components shaping the frequency response. This kit places you at the heart of this "studio" logic: adjust, compare, refine... and retain what really works on your rig.

Who is this kit for, and in which styles does it make the most sense?

This bundle is aimed at curious guitarists, educators, makers, and pedal enthusiasts who want to move from usage to understanding. New to electronics? The breadboard format (no soldering for assembly on the board) is ideal for stress-free learning: you build, listen, and correct. Already comfortable? You gain a quick tool to prototype an EQ section, compare several values, or prepare a "final" version intended for a future pedalboard.

Musically, a 3-band EQ is a Swiss army knife: blues and classic rock to thicken the low end and tame overly sharp highs, funk to clean up the bass and bring out the attack, metal to adjust presence and control the low spectrum, ambient and post-rock to precisely place the guitar in the mix. In the studio, it's an excellent tracking companion: you correct the guitar at the source. Live, it's a formidable solution to adapt your sound to a venue (while keeping your identity).

A DIY experience designed for fast prototyping and clean progress

The Cir-Kit principle is simple: you have a breadboard dedicated to the audio signal and an intuitive guide that walks you through the assembly step by step. The goal is not only to get a functional effect but also to help you understand "why" each connection exists. You progress at your own pace, following a progressive method that greatly reduces common mistakes (polarities, power rails, placement accuracy, etc.).

And because DIY is also about good habits: get into the habit of testing your components and checking your assembly throughout the steps. A breadboard encourages experimentation, but that's also what makes it demanding: a misoriented component, a shifted connection, or reversed power supply can be enough to make you lose time. Here, the guided approach is precisely there to help you learn to diagnose, correct, and progress independently.

Sound

A well-designed 3-band EQ doesn't just "boost" or "cut": it gives you the feeling of repositioning your guitar in the mix. Expect effective equalization to tighten the bass (without muddiness), shape the mids (to move forward or back in the band), and adjust the highs (to regain brightness or, conversely, tame a harsh amp). On an already saturated chain (overdrive, distortion, fuzz), the EQ becomes a precision tool: you can tighten the low end, avoid the "muddy" effect, or highlight a frequency that makes your leads sing.

As with any breadboard assembly, the result will depend on your wiring, power supply, and tests: that's exactly the point. This kit is made so you can hear the differences, understand what you're modifying, and build your own vision of the "perfect EQ" for your guitar, pickups, and amp.

Technical specifications

Effects	EQ	Type	sector
Technology	Analog	Use	electric guitar
EQ	3 channels

Model	3-Band EQ	Power supply	9V DC, center negative
Integrated connectors	audio input and output	Required voltage	9V DC (center negative)
Input	6.35mm Jack	Recommended current	provide a power supply capable of delivering at least 100 mA to cover all tests and assembly variants
Output	6.35mm Jack