Results of Testing my Turntable using the HiFi Sound HFS75 Test Record

The pickup arm is a Linn Ittok LVII. This is a fairly early Ittok, with the two-piece counterweight.

The cartridge is a Linn Karma AL22621. This is a low-output moving coil type. Although I have had this cartridge for several years, inspection does not show any noticable stylus wear, and it still sounds fine to me.

The phono preamp is a Naim 42.5, with K series input boards made specifically for the Karma.

The soundcard used is an M-Audio Audiophile 2496, and all recordings were made in 16 bit, 44.1kHz, stereo. The recording level was left set to a typical level that I use when transferring music LPs.

The results of the tests are downloadable below. All the download files are FLAC lossless compressions of the original WAV files as recorded. To reduce the size of these files, I have included just a few seconds for each test. Since they are basically steady-state signals, I saw no reason to make them any longer.

• Soundcard input alone. This demonstrates the soundcard's noise floor on its own, without the preamp attached.
• Preamp alone. This is the preamp without the turntable motor switched on. It is effectively the background noise of the preamp plus soundcard.
• Turntable motor switched on, but no record playing. This adds any possible additional noise due to pickup by the cartridge of hum fields from the motor.
• Acoustic pickup. This signal was recorded with the preamp turned on and the stylus resting on a stationary LP while fairly loud music was played and directed towards the turntable. It demonstrates the amount of environmental noise that is picked up by the cartridge. (If you can't quite place the tune, it's "Everybody's Got Something To Hide" from The Beatles White Album).
• Channel phasing test. Warble tones to reveal the quality of the central image. In phase. Out of phase.
• Channel balance and separation test. 1kHz signal at 5cm/sec. Left channel only. Right channel only. An interesting observation here is that channel separation appears to be about 28dB when only the right channel is modulated, but only about 22dB when only the left channel is modulated.
• Lateral modulation. 300Hz signal at +11dB ref. 1.12 x 10^-3 cm peak.
• Lateral modulation. 300Hz signal at +14dB ref. 1.12 x 10^-3 cm peak.
• Lateral modulation. 300Hz signal at +18dB ref. 1.12 x 10^-3 cm peak. This exhibits fairly catastrophic mistracking. I have owned a fairly wide range of cartridges over the years (ADC VLM, Ortofon FF15E, Grado F1+, Dynavector 10X, Supex 901E, Linn Asak, and now the Linn Karma), and none of them have been able to track this cut. Note that I have never owned a high compliance moving magnet (eg. Shure V15), which are reputed to be able to track these kind of signals. That said, I have never noticed mistracking on normal music LPs using the cartridge under test here. I feel that this "torture cut" is only of academic interest. (There again, if I owned a cartridge that could track it, I'd probably feel rather smug :-)
• Vertical modulation. 300Hz signal at +7dB ref. 1.12 x 10^-3 cm peak.
• Vertical modulation. 300Hz signal at +11dB ref. 1.12 x 10^-3 cm peak.
• Pink noise. 20Hz-20kHz, -3dB per octave. Nominally -15dB ref. 5cm/sec at 1kHz.
• White noise. 20Hz-20kHz. Nominally -15dB ref. 5cm/sec at 1kHz.
• Rumble. Starts with a 10cm/sec 1kHz reference, followed by silent grooves. You can hear that the cartridge is on the edge of mistracking the 1kHz reference signal.
• Lateral modulation at outer grooves of record. 300Hz signal at +15dB ref. 1.12 x 10^-3 cm peak. Some minor mistracking can be heard on the right channel.
• Lateral modulation at centre grooves of record. 300Hz signal at +15dB ref. 1.12 x 10^-3 cm peak.
• Lateral modulation at inner grooves of record. 300Hz signal at +15dB ref. 1.12 x 10^-3 cm peak. Mistracking is clearly audible, more so on the right channel.
• Wow and Flutter. 3kHz signal at 5cm/sec, for use with wow and flutter meters. I do not have such a meter, so cannot report what this signal shows about my turntable.