Bottlehead
Crackatwoa Headphone Amplifier Kit
Best high fidelity audio for dedicated DIY enthusiasts.
The Crackatwoa is a premium evolution of the beloved Crack amplifier, designed for high-impedance headphones (200 ohms and above). It offers enhanced sonic refinement, more input flexibility, and superior upgrade potential. The direct-coupled circuit is upgraded with C4S active loads and shunt voltage regulation, supported by a larger power transformer for a quieter background, greater bandwidth, and tighter bass control. With three switchable RCA inputs and a built-in balance control, it provides a refined listening experience.
$959.00
More Crack Options
Owner Satisfaction
4.7
/ 5
Category Rank
63
/ 1078
#63 in Headphone Amplifiers
Price vs Category Average
-32%
Below average
Tube Complement
608012765
/ One , one AU, two AQs
Who it's for
- Audiophiles seeking a rich, engaging, and high-fidelity listening experience
- Enthusiasts who enjoy hands-on projects and understanding their gear's internals
- Savvy consumers desiring top-tier audio quality without the premium pre-built cost
Who should skip it
- Beginners or those lacking experience with intricate electronic assembly
- Listeners primarily using low-impedance or in-ear monitor headphones
- Impatient builders or those uncomfortable troubleshooting electronic circuits
Performance breakdown
High-Impedance Synergy
Specifically engineered to make high-impedance headphones sing with authority and grace.
Sonic Resolution
C4S active loads deliver exceptional detail and a remarkably quiet noise floor.
Build Complexity
Requires significant soldering experience and patience to assemble correctly.
Input Versatility
Three switchable RCA inputs offer rare flexibility for a tube amplifier.
Bass Control
Shunt regulation provides the tight, punchy low-end response tube amps often lack.
Upgrade Potential
A tinkerer's dream with endless room for component rolling and circuit modifications.
Key Specs
Tube Complement
One 6080, one 12AU7, two 6AQ5s
Compatibility
High-impedance headphones (200 ohms or higher)
Amplifier Technology
Vacuum Tube
Power Supply
Upgraded with dual 6AQ5 tubes for shunt voltage regulation
Inputs
Three switchable RCA inputs
Controls
Built-in balance control
Max supported impedance
600 ohms
Know before you buy
No, the Crackatwoa is specifically optimized for high-impedance headphones, ideally 200 ohms or higher. Using it with low-impedance gear will likely result in poor performance and impedance mismatching.
The Crackatwoa is a significant step up, featuring a direct-coupled circuit with C4S active loads and shunt voltage regulation. These upgrades provide a quieter noise floor, tighter bass control, and better bandwidth compared to the original design.
This kit is intended for experienced builders. While the instructions are thorough, the circuit complexity and the nature of high-voltage tube amplification require prior soldering experience and a solid understanding of safety protocols.
Yes, it features a built-in balance control, which allows you to adjust the volume and channel balance directly on the unit. It also includes three switchable RCA inputs for connecting multiple sources.
You can expect the classic, organic warmth of an OTL tube circuit, but with improved resolution and dynamic impact. The addition of the Speedball constant current source and shunt regulation gives it a more refined, modern presentation than traditional tube amps.
Yes, the kit comes with the necessary tube complement: one 6080, one 12AU7, and two 6AQ5s for the shunt voltage regulation stage.
Still have a question?
Ask Hayley anything about this product before you decide.