Crack

About the Crack

The Bottlehead Crack is an OTL headphone amplifier kit, specifically designed for higher impedance headphones such as those from Sennheiser, AKG, and Beyer, typically above 200 ohms. It is classified as a tube amplifier, utilizing common tube types like the 12AU7 and 6080 or 6AS7. The Crack is known for its clean sound, deep bass, and natural mids. It features a simple circuit, making it suitable for beginners, with a low parts count that keeps the price affordable. The amplifier includes a power supply similar to Bottlehead's Foreplay, with ultrafast rectifiers and a C-R-C-R-C configuration, providing a quiet background. It offers a gain of about 15dB into a 300 ohm load and can output up to 10V into the same load. The Crack is praised for its ability to enhance the sound of certain headphones, particularly the Sennheiser HD-650, but may not perform as well with lower impedance models.