Phono preamp FAQ

Hi All....

Starting this thread to better understand the "phono preamps or phono stage" before I cough my dough for an upgrade.

Seen some of these "stages" come with "MM / MC" or "MM" and "MC". And have additional features like "rumble filter" or "V" control.

Mine currently is a Rega Mini, a good entry level unit. Should i say not focused to my ears.

Contribution to this thread is appreciated in advance.

Cheers

saw this from internet..


MC or MM cartridges? The choices the beginner in vinyl playback has to deal with can be myriad. For example ,for your first turntable do you go for one with belt-drive, direct drive or even idler wheel. How about whether the turntable should be one with a solid mount plinth or whether it should be suspended. Besides these choices based on the fundamental construction in turntable designs, the 'involved' beginner may also want to consider the choices of tone arms and types of phono cartridges. Whether this will be a low output MC or a high output MM cartridge. This is on top of the choices of the many competing names in common designs. The confused beginner will often leave the decision to a trusted 'authority' among friends who happened to have a bit more experience spinning vinyls. Others would just find something within their budget, which is recommended by some respected hi-fidelity magazines.
A little knowledge will be always helpful towards making some intelligent choices. Due to space constraints, this discussion will be limited to that of MM/MC phono cartridges.
For the beginner the MM or moving magnet phono cartridge would be the cartridge of choice. The term moving magnet refers to the method used to regenerate the music signal from the record grooves. A tiny, powerful magnet is attached to the diamond tipped cantilever, which actually traces out the music signals from the record grooves. The movement of the cantilever is transmitted to the magnet, which moves in a coil formed from very fine wires. This movement of the magnet in the fixed coils generates the tiny electrical signal, which is then input into a special phono circuit to amplify it to a usable level. Typical output of this type of cartridge is 5 mV. This allows the turntable output to be fed directly to a basic phono input. This type of cartridge is usually quite robust and is thus suitable for use by a beginner.
An MC cartridge uses a similar motor system as the MM cartridge except that the magnet is fixed and the coils, which are fixed to the cantilever vibrate in response to the movement of the stylus tracking the record grooves. The coils have fewer numbers of turns than that of the moving magnet, and are thus lighter and have much lower impedance and inductance. These factors allow for a wider bandwidth and better retrieval of low level information. The MC phono cartridge is thus technically superior to the moving magnet however it does have a number of down sides, which prevents it from being widely use. The main problem with it is the much higher cost. This is not just the higher cost of the MC phono cartridges themselves but also the cost of extra ancillary equipment. This is due to the low output of the MC phono cartridge, which is typically about 0.2 mV. This requires the use of an extra amplification stage. Good quality step-ups as these are called do not come cheap. And if you use an outboard MC step-up device, there’s the additional cost of another pair of interconnects. The cheapest MC phono cartridges are many more times the cost of the cheapest MM cartridges. There are hardly any MM phono cartridges above $1000, but I know of at least one MC cartridge coming in at above $10000. Besides the cost factor, there’s the problem with MC cartridges being rather delicate compared with their MM cousins. That’s why in the arena of DJs, moving cartridges are used exclusively because they stand up to some of the worse abuse that is seldom encountered in the home settings.
Thus for a person who is just starting out spinning vinyl, it is best to go with a modest moving magnet set-up. If properly done, it does not give anything away in terms of musical performance and enjoyment. Compared with a well set-up MC based system, it would lose out in terms of low level resolution. Consider also that a poorly set-up MC based system can sound horrendous, and often worse than a mediocre MM based system. The greater definition of a MC cartridge can often work against it.
For me I am perfectly happy playing with cheap moving cartridges. It is possible to achieve very satisfying sound using a modest cartridge on a high quality turntable/ tonearm combination. Try using a super high quality on a mediocre turntable/ tonearm and you will find the first combination far more enjoyable. This is because in the hierarchy of vinyl playback, the cartridge occupy the lowest rung of importance below that of the turntable and the tonearm.