In the past few weeks, we’ve been booked for numerous tech support jobs, from addressing unusual groove patterns to installing and setting up Vinyl Recorders.
A recurring issue with Vinyl Recorder support jobs is recalibration, particularly adjusting playback reference to 0dbu on your level meter. A common problem we encounter is the system being miscalibrated due to the inaccurate test record supplied with the Vinyl Recorder. We have three of these lathes, each with a different test record, and the 1kHz sine wave test tone varies by 9db across the discs, which is quite significant, not only this but left and right imbalance.
This discrepancy means that your levels are inaccurate from the start when you begin cutting and calibrating playback. Additionally, the supplied level meter has its pots glued, preventing adjustments even though it was calibrated to an inaccurate test record.
We recommend using the ‘Ortofon Test Record’ for calibration. We’ve tried several types and found this one to be highly accurate and easy to use. It also makes checking azimuth straightforward, ensuring accurate level on both the left and right channels independently. Also, consider getting a new level meter, such as the same as the one supplied with the Vinyl Recorder, a IMG Stageline, which goes to +12 on the meter. A new meter without glued pots is essential for proper calibration.
In summary, get a professional test record and calibrate your reference level correctly from the beginning! Any jobs we take on for support will need one, calibration is something that we will go through 99% of the time.