Cartridge loading. Moving coil cartridges usually have a much lower output than their moving magnet counterparts by virtue of having a coil moving, rather than the magnet to produce a voltage. Whether you are using a step-up transformer or a moving-coil phono pre amplifier to achieve the extra gain required for a moving coil cartridge (about 20dB more than a MM cartridge), the importance of cartridge impedance matching remains the same.
A poor impedance match between a moving-coil cartridge and the device adding the extra gain can be the cause of disappointing sound quality-high frequency audible “ringing”, a clearly uneven frequency response and generally high noise. The graph below shows the effect that cartridge loading resistance can have on frequency response. It's easy to attribute some of the potential performance problems of a turntable combo to a poor mechanical match between the arm and cartridge, or even to the tracking ability or “sound quality” of the cartridge itself. Hagerman Technology LLC: Cartridge Loading. Cartridge Loading This is a quick study of various phonograph cartridge loading conditions, a rather straightforward analysis using a simple model in Pspice.
Obviously, real-life conditions are far more complex, but general trends and first order results can be realized. Effects of RIAA equalization have not been taken into account - perhaps altering the results a little. The basic schematic is shown below. A cartridge's electrical response is simulated by a voltage source in series with an inductance (Lc) and resistance (Rc). Many moving magnet cartridges have inductances up to 500mH. The first thing we notice is that the circuit forms a basic LC resonant tank.
The larger the inductance, or larger the capacitance, the lower the resonant frequency will be. Looking at the "middle" cartridge (50mH & 100 ohms) into a 47k resistance, the loading capacitance was varied from 0pF to 400pF. Ok, so where's the advantage of a moving coil? So there you have it. Load Resistor Tuning MC Cartridges. Cartridge Database Tools - Vinyl Engine. A Beginner's Guide to Cartridge Setup. [The fine print: The cartridge setup procedure described here is to be used solely as a guideline, and may not be applicable to all cartridges and tonearms. If the instructions here conflict with those provided by your cartridge or tonearm manufacturer (assuming you're fortunate enough to get any), follow those from the manufacturer.
Furthermore, Audiophilia will not be held responsible for any damage sustained by your cartridge, tonearm, turntable or anyone foolish enough to sneak up on you from behind while following these instructions.] With the near-complete erosion of support for vinyl playback at the retail level, audiophiles devoted to the analog disc have little recourse but to become adept at the finer points of cartridge setup. And while correctly setting up these delicate devices does require relatively vast amounts of both time and patience, the steps involved are well within the scope of the audio enthusiast with a steady hand and the right tools at his disposal. 1. 2. 3.
Conrad's TT Alignment Template. 3 Ways to Change the Needle on a Vinyl Player. Arc Protractors Cartridge Alignment Made Easy - Home. Turntable Setting "Overhang" The animated graphic here is taken from the DVD "21st Century Vinyl: Michael Fremer's Practical Guide to Turntable Set-up". The gauge is similar to the kind supplied by Pro-Ject and other turntable manufacturers.
It's accuracy is predicated upon the correct pivot-to-spindle for the particular tonearm. If your turntable is one that's factory supplied with the arm, chances are very good that distance will be correct. If your 'table has the armboard drilled by a dealer or the person from whom you bought the 'table used, measure the distance and be sure it meets spec! You can find out pivot to spindle distances on the the vinyl engine.com website. This gauge sets the "overhang".
The gauge shows the two "null" points where there is zero tracking error (the stylus is tangential to the groove) if you accurately set up the stylus! Now carefully lift the stylus using the cueing lever and move the arm to the inner grid (of course you'll have to move rotate the gauge). Turntable Set-Up. If the mechanical adjustments are not correctly made a distorted signal will be the result. If you have done your best and distortion persists, and it is not caused by the maltreated record groove, you should check the diamond tip of the cartridge or have it checked by a professional.
A used diamond has at its very tip very small facets that cannot be seen with the naked eye. They are at the end of the tip and not on the sides above the groove as many do expect when checking a tip. These facets let the tip act as a chisel that will "cut" the grooves, especially the grooves which contain high dynamics. If you play with a good tip and if down force and side thrust are well adjusted, than you can listen to your records many and many times without the quality diminishing. If you use a tone arm with e detachable headshell, you can optimize the sound reproduction by choosing the headshell which will give the best harmonics, the best attack and transient and the most even frequency curve.
Gizmodo. turntable calibration.