Ortofon heritage and the new technology

Ortofon measurement technique, part 1.

We would hereby like to present how we at Ortofon perform the tests of the cartridges during the production process. We will shed light on the following areas of the testing system:

• The measurement chain and the records used
• The quality of the test system

The measurement test chain 

The Ortofon measurement testing set-up is a PC based testing system. Prior to testing, the cartridge is mounted on a special headshell, that has been optimized for repeatable and reproducible use. The cartridge is connected to an amplifier, which is adjusted for an input impedance of either 100ohm, 200ohm or 47kohm/220pF (cable capacitance incl.) depending on two elements:

1. The impedance characteristics of the cartridge
2. The type of cartridge, i.e. Moving Magnet or Moving Coil

Then the signal is amplified with a gain of +40dB for MM and +60dB for the MC types.The amplifier has a switch for the measurements with/without RIAA-equalization. For lower frequencies below 1kHz the test will be performed with the RIAA equalization curve set on ON/automatic. For high frequency tests the switch is turned OFF allowing maximum bandwidth since the records have been cut linear and non-equalized.

Subsequently the signal is converted through an AD-converter and filtered for optimal use of the PC capacity. The data is finally stored on a hard disk.

For each MM/MC model a set of limits, reflecting the performance of the cartridges, will be used.

After the system is hooked up, a calibration sequence is initiated and the data stored. The sequence compensates for changes in temperature, humidity etc. The calibration sequence also compensates all cables, impedances, gain etc. in the measurement chain from the headshell to the PC.

Three sequences of the test

1. Testing sensitivity, channel separation and balance: we use track 1 and 2 on DUAL PVK 321. The measurements are performed at 1kHz with a speed of 5cm/s. The AD-sampling is at 40 kHz, an average of 1000 measured data is used. The filter is a Bessel IIR Band Pass of 6th order with cutoff frequencies of 50Hz and 10kHz.
2. Testing tracking: we use track 4 on DIN 45549. Detection of tracking is performed at 315Hz. It is registered on the 4th, 5th and 6th harmonics in an FFT signal analysis. The filter is similar to what is applied in the first test sequence.
3. Testing frequency response: we use the Technical Record Series from JVC -1005 track 1-6. For this test the sampling is performed at 250 kHz, an average of 3000 measured data figures is used. The filter is a Bessel IIR Band Pass of 3rd order with cut off frequencies of 500Hz and 80kHz.

After testing, the product is approved by the quality control if the product performance data meets the given test specifications. All Ortofon cartridges are subject to quality control and test.

Measuring chain

The steps in the measuring chain are subsequently:

1. Cartridge mounted in test headshell and/or tonearm 
2. Amplifier with RIAA switch
3. AD converter
4. BandPass filter: 6th order Bessel (IIR)
5. PC (Results for QC)
6. Store data on HDD

Test equipment (subject to changes):

Test records used:

Calibration equipment (subject to changes):

Ortofon-Serato S-120 DJ cartridge 

Ortofon is proud to announce the release of a revolutionary new high performance cartridge for DJs, co-developed with Serato Audio Research.

The new Ortofon-Serato S-120 DJ Cartridge has a patent pending design using a unique suspension system. This patent pending technology will probably be used in future HiFi products.

All vinyl DJs will benefit from the extreme tracking ability delivered by a revolutionary new cantilever suspension. With 4.0 gms of vertical tracking force, the Ortofon-Serato S-120 achieves an amazing tracking ability of 120 μm compared to the conventional 80 μm at 315Hz. That is a 50% improvement on the standard DJ cartridge performance.

Mr. SPU Robert Gudmandsen   

Robert Gudmandsen, known by most as Mr. SPU, is the father and founder of the Ortofon large pickup program, which is still the world's largest by a single manufacturer.

Robert Gudmandsen began working with Ortofon on December 6th, 1941 and remained in the company for more than 50 years. When celebrating his 50th anniversary with Ortofon, Robert Gudmandsen was awarded Her Majesty Queen Margrethe II meritorious medal.

Robert Gudmandsen started his career as a radio engineer in a company where his father also worked, and from there he was brought to Ortofon by Arnold Poulsen, one of the Ortofon founders. Initially, Robert Gudmandsen worked on the production of a dynamic amplifier for a local radio station.  Later he was also involved in the production and development of condenser microphones.

In 1945-46 Ortofon started production of cutting heads for the mastering of new LP records. This led to the development and introduction of the first SPU - Stereo Pick-Up in 1948, the SPU being the first Moving Coil pickup in the world. This first stereo pickup actually consisted of two parallel-mounted pick-ups. The armature was connected to a common cantilever via an extremely complicated universal joint with sapphire bearings. (The universal joint design is no longer applied for the production of Moving Coil pickups). The SPU also has a new elliptical needle, which gives somewhat lower wear at approx. 4-g needle pressure.

Along with the production of MC cartridges, Ortofon also developed Moving Magnet pickups.
These were initially somewhat clumsy and had a very low output. Robert Gudmandsen was involved in the development of the Variable Magnetic Shunt principle that solved many problems; among other things it obtained a high output and had a very low moving mass. A contributing factor to the success of the VMS pickups was a specially developed rubber suspension, that together with the low mass secured a very large frequency range.

The VMS pickups, although well received, were replaced with new technology in the 80's, where an even higher output of the MM pickup was obtained.

For many years Robert Gudmandsen brought the pickups home to test them. It was something that both neighbors as well as other local residents enjoyed. Today Robert Gudmandsen has many other hobbies outside of audio. When he does choose to enjoy music, he prefers opera, for example the Prisoner chorus from Verdi's Nabucco and also the Norwegian soprano Sissel Kyrkjebø.

Today Ortofon has the world's largest program of pickups in all price ranges and all types, but despite the development of the new pickups from Ortofon, Robert Gudmandsen, as well as a legion of music aficionados, prefer the sound of the good old SPU. Robert Gudmandsen enjoys his retirement in the small town of Præstø, located between Copenhagen and the Ortofon headquarters in Nakskov.

Recent reviews

In the Newsletter to come

• Measurement technique, part 2
• TA cables
• Individual cables
• New product range