Headphones the Bottlehead Crack 1.1 Drives

Desktop Tube · Single Ended

Output impedance 120.0 Ω manufacturer
Output type Single Ended Desktop Tube
Power output 333 mW @ 300 Ω 166 mW @ 600 Ω*est.
Bottlehead product page (bottlehead.com/products/crack-1-1-otl-headphone-amplifier-kit): output impedance 120 Ω (published). Power: '~10V into a 300 ohm load' → P = 10²/300 = 333 mW; the '~' qualifier makes this approximate. 600 Ω derived from 300 Ω voltage ceiling (~10 V). Designed for 300–600 Ω headphones only. · Source ↗
23 ample 8 adequate

✓ Ample headroom 23

Headphone Headroom Damping Driver
Koss Porta Pro Ample 20.8 dB ⚠ caution Dynamic
Grado SR80x Ample 20.5 dB ⚠ caution Dynamic
AKG K371 Ample 20.0 dB ⚠ caution Dynamic
Sennheiser HD 560S Ample 18.9 dB ⚠ caution Dynamic
Sony MDR-7506 Ample 18.8 dB ⚠ caution Dynamic
Sennheiser HD 660S Ample 18.7 dB ⚠ caution Dynamic
Meze 99 Classics Ample 18.2 dB ⚠ caution Dynamic
Sennheiser HD 800 S Ample 16.8 dB ✓ ok Dynamic
Philips SHP9500 Ample 16.2 dB ⚠ caution Dynamic
Audeze LCD-2 Classic Ample 16.2 dB ⚠ caution Planar
Sennheiser HD 599 Ample 16.1 dB ⚠ caution Dynamic
Sennheiser HD 600 Ample 15.7 dB ✓ ok Dynamic
Sennheiser HD 650 Ample 15.6 dB ✓ ok Dynamic
Audio-Technica ATH-M50x Ample 15.5 dB ⚠ caution Dynamic
Focal Clear (original) Ample 15.3 dB ⚠ caution Dynamic
Audio-Technica ATH-AD700X Ample 15.2 dB ⚠ caution Dynamic
Audeze LCD-X Ample 14.8 dB ⚠ caution Planar
Drop + Sennheiser HD 6XX Ample 13.0 dB ✓ ok Dynamic
Beyerdynamic T1 (3rd Gen) Ample 12.2 dB ✓ ok Dynamic
Beyerdynamic DT 770 Pro 80 Ample 11.4 dB ⚠ caution Dynamic
Beyerdynamic DT 880 Pro Ample 10.8 dB ✓ ok Dynamic
Audio-Technica ATH-R70x Ample 10.2 dB ✓ ok Dynamic
HiFiMan Arya Ample 10.2 dB ⚠ caution Planar

◑ Adequate headroom 8

Headphone Headroom Damping Driver
Beyerdynamic DT 770 Pro 250 Adequate 9.7 dB ✓ ok Dynamic
AKG K702 Adequate 9.6 dB ⚠ caution Dynamic
Beyerdynamic DT 990 Pro Adequate 8.6 dB ✓ ok Dynamic
AKG K712 Pro Adequate 8.1 dB ⚠ caution Dynamic
HiFiMan Sundara Adequate 7.9 dB ⚠ caution Planar
HiFiMan Edition XS Adequate 7.0 dB ⚠ caution Planar
AKG K240 Studio Adequate 6.2 dB ⚠ caution Dynamic
Fostex T50RP Mk3 Adequate 4.3 dB ⚠ caution Planar