note: a full write-up of the following pilot study will appear soon.

Over the winter break, we ran a pilot test of our perception study. The setup for this test is a A-B preference test, where recordings made on different phonograph playback systems are compared. The systems each consist of a cartridge, turntable, preamplifier, and interconnects. The key difference between each type of component in these two systems is that one is of a significantly higher price range than the other. The 2 systems are detailed below (note: the interconnects between turntable and preamp are Kimber Kable Tonik for both systems; the internconnects listed are between preamplifier and PrismSound A-D converter):

more expensive:

• cartridge: Ortofon Kontrapunkt B
• turntable: VPI HR-X w/JMW Memorial tonearm
• preamplifier: Manley Steelhead
• interconnects (preamp to A-D conv.): Kimber KCAG
  

less expensive:

• cartridge: Ortofon Kontrapunkt A
• turntable: VPI Aries 2
• preamplifier: Pass Labs XONO
• interconnects (preamp to A-D conv.): Kimber PBJ
  

We recorded five 15-second audio clips with both systems twice, resulting in 20 recordings (four for each audio example). The files were recorded with the use of a PrismSound ADA-8XR analog to digital converter, routed by firewire to Apple Logic 7. Each file was recorded in 24-bit and 96 kHz audio in Logic 7, and time-aligned using Audacity audio editor. The clips used (taken from our collection of vinyl recordings) were:

1. Michael Jackson - Don't Stop 'Til You Get Enough
2. Sergei Prokofiev - Dance of the Knights (from Romeo and Juliet)
3. Pink Floyd - The Great Gig in the Sky
4. Weather Report - Birdland
5. Manhattan Transfer - Operator
   

These clips were selected as they were determined to be the most revealing in the task of distinguishing the two systems during the creation of the systems themselves.

All four recordings of each audio clip were presented in a block, which consists 10 trials. In each trial, 2 of the recordings (A and B) are first played in their entirety. The participant is then asked to select their preferred clip. Before making a choice, they may use the testing interface controls to either play A or B from the beginning, or to switch between the two files mid-playback, continue from the same position in the alternate clip. Once all 10 trials have been completed by the participant, they are instructed to take a two-minute break, before they continue to the next block. Prior to the start of the actual test, the participant is guided through a training block, which is similar to the testing blocks, except this is the participant's first experience with the interface and audio examples.

The files were played at 24-bit/96 kHz via a Max/MSP patch on a Mac Pro with a RME MADI HDSPe audio interface. Participants listened to the audio in an acoustically-treated facility through 2 Wilson Watt/Puppy speakers, powered by a Bryston 14B amplifier.

In total, 14 participants completed our pilot study. We are now reviewing the results of the test and will use these results to determine the next appropriate steps to take.