equipment
---------

Stanton T.120C turntable
Shielded stereo RCA connectors from Radioshack
M-Audio Delta 1010LT sound card with analog through
RCA to 1/4" adapters
1/4" inch stereo to mono Y splitter
1/4" - 1/2" adapter
Headphones from Radioshack

software
--------

Ubuntu Linux 2.6.22-14-rt
jackd - low latency audio server
jack-rack - for gain 1 digital amplifier
qjackctl - Qt gui for controlling jack
pyjack - python bindings for controlling jack
jc2 - custom script for controlling jack connections
analog_divide - custom double-blind survey script

test records
------------

Bjork - Telegram
Blonde Redhead - La Mia Vita Violenta
Blonde Redhead - Melody of Certain Damaged Lemons
Blonde Redhead - Self-Titled
Boards of Canada - Trans Canada Highway
Jethro Tull - Aqualung
John Daly - Sky Dive EP
Joni Mitchell - Song to a Seagull
Neil Young - After the Gold Rush
Neil Young - Harvest - French Release
Schubert - Winterreisen (Fischer - Dieskau)

procedure
---------

Unfortunately, pyjack was crashing with a double-free on exit, and we were unable to suppress the stack trace from bash. Linux glibc I hate you. The double-blind test script was out, so we had an operator randomly patch the subject in to either the digital or analog signal and record their guess. The subject was allowed to switch between channel #1 and channel #2 as many times as they wanted before guessing which was which.