Bottlehead Crack

I am offering for sale a newly completed
Bottlehead Crack 1.1 Tube Headphone Amplifier with the Speedball Upgrade. The
Crack is an OTL (output transformer-less) tube headphone amplifier designed for
use with higher impedance (>200 ohms) headphones. A favorite of Sennheiser
headphone aficionados, the Crack pairs extremely well with Sennheiser HD 600,
HD 650, and HD 800 (or HD 800 S) headphones. It also works very well with many
Beyerdynamic and AKG headphones.  

I just completed construction of this Crack 1.1
and it sounds super! As for my credentials, I have degrees (B.S. and M.S.) in
electrical engineering and experimental physics and in the early part of my career
I spent some years doing mainly electronic work (electronic design, assembly,
testing, and software design)  in the research and development department
of an instrumentation company in Sweden. I know electronics and can easily tell
the difference between a good solder joint and a cold one. I like to build tube
amps for fun.     

This amp is very well-built and sounds great.
High quality Kester 63/37 rosin core solder was used throughout. The stock
Crack is built entirely using point-to-point wiring, and the Speedball upgrade
adds two circuit boards to the assembly. The Crack 1.1 uses 12AU7 and 6080
triode tubes for input and output. This particular Crack comes with upgraded
tubes. Of particular note is that the 12AU7 is an RCA clear top, reputed to
have great sonic qualities, and a Raytheon 6080, both made in USA NOS tubes. The Speedball
is a Camille Cascode Constant Current Source that deepens the bass, lowers the
noise floor and overall intensifies the already awesome Crack performance.
The alder wood base has been finished with a six-coat
hand-rubbed polyurethane finish.  The wooden base comes complete with the
Bottlehead badge. The transformer bell has been finished in hammered silver. Also
included is a new power cord, a user’s guide, and original build instructions
for both the Crack 1.1 and the Speedball upgrade.



I will guarantee the quality and performance of
this amp and will accept returns for a full refund of the purchase price if you
are not satisfied for any reason.  The Crack will be well-packed to ensure
no damage to the electronics or the wooden base. I secure the electronics
chassis to its own wooden box separate from the wooden base to avoid any
marring of the woodwork or damage to the electrical components and wiring, and
both are packed in a double-weight box for shipment.