The Unitra test record was specially designed to enable verification of hi-fi audio equipment under everyday usage conditions, where we most often listen to music, which is at home. The vinyl contains basic test signals developed by Unitra experts, placed on sides A and B. The recordings allow for accurate measurement of various indicators used to calibrate the performance of the phonograph cartridge. The calibration record can be used with Unitra GSH-630 Fryderyk and GSH-801 Edmund turntables, but also with any other device available on the market.
Expertise and experience
The basic Standard test vinyl was created in collaboration with a domestic Polish company, which shares extensive knowledge and experience in analog sound with Unitra. The creation of these records would not have been possible without the valuable experience of recording and mastering engineers. Other external specialists and the experienced team of Unitra engineers, for whom turntable construction is a daily activity, also contributed their knowledge. The goal of all the experts involved was to achieve the highest quality and fidelity of stereo reproduction.
Standard Test Disc Content
The Standard record contains:
Instructions for tonearm calibration. There is a detailed guide that will help you accurately adjust the turntable's tonearm step by step. In five steps, from setting the VTA angle, through azimuth, stylus contact with the record, cartridge tracking force, and anti-skating.
The vinyl record with sides A and B has a printed pattern (protractor) that serves as a calibration template, audio tracks with test signals, and an anti-skating slip tester.
Side A
Track 1. 20 Hz – 20 kHz log −20 dB
Track 2. 20 Hz – 15 kHz log −14 dB
Track 3. 20 Hz – 2 kHz log 0dB
This section contains a series of frequency responses for checking and plotting the transfer characteristic of the cartridge. The use of different recording levels allows achieving different frequency ranges. The maximum continuous response of high frequencies is limited by any vinyl cutting machine (technological limit of the medium). A low recording level allows for a higher frequency response, but with a worse SNR (Signal-to-Noise Ratio).
Track 4. 30 Hz – 15kHz log −14dB VU [step]
In the last recording, the frequency response is divided by pauses. The recording level is -14 dB below the standard reference level. An oscilloscope is best for evaluating this simple test.
Side B
On this side of the record, there is a smooth area without grooves that allows for checking the anti-skating setting, and a silent groove for testing the mechanical isolation of the turntable. We verify the effect of anti-skating using the protractor and by observing the reaction of the tonearm when lowered onto the rotating smooth surface of the record.
The silent groove without any recording will help you experiment with various methods and hardware designed to limit vibrations. By reducing the transmission of mechanical noise, you will achieve maximum sound quality. For the best test results, use closed-back headphones.
Getting Started
How to set up the turntable before testing?
To properly perform measurements using the Standard test record, carefully read the instructions for operating the turntable and tonearm. The tonearm's parallelism with the vinyl record's surface is crucial. The user should also set the tracking force (VTF, Vertical Tracking Force) and anti-skating by the cartridge manufacturer's recommendations.
Recommendations
We recommend performing the following steps before and after each playback to achieve optimal sound quality and minimize wear on the record and stylus.
