Originally Posted by Airsculpture
I'm not. I'm asking a perfectly civil question from a stand point of having very little knowledge on the subject.
If you can't be bothered to enlighten then that's ok.
This is a forum for gaining knowledge right ? I don't have any knowledge on the subject as stated, never having used one, so was asking to find out.
The amounts I quoted were just figures out of the air, ignore them.
Sent from my iPhone using Tapatalk
Here's how it works:
First a little background.
A vinyl record is literally a mechanical representation of an analogue sound. A lower frequency has a wider/longer grove to be an analogue of the low frequency sound and a higher frequency has the opposite. The “master” that is used in pressing vinyl records is literally cut in a type of lathe with a cutting tool that is not so different from the needle in a phono cartridge. The “cutting needle” is fed the recorded signal and vibrates to cut an analogue groove of the sound.
To use the vinyl media in a more efficient way, equalization is applied to the recording which will allow for longer recording times, by decreasing the width of the groove, improve sound quality/reduce high frequency hiss, and reduce the groove damage/wear that would occur during playback.
The RIAA or Recording Industry Association of America, developed the equalization curve that has become the global industry standard in this process. This happened sometime in the early 1950’s. And yes, it’s the same RIAA that sues and enforces DRM of recorded properties.
The RIAA equalization curve, during recording, reduces the low frequencies and boosts high frequencies. This reduces the groove width to better use the surface area available on a record and the amount of movement the phono cartridge needle or “stylus” must vibrate during the recording/cutting process and playback.
Now, here’s where the phono pre-amp comes in. The phono pre-amp applies the equalization curve in reverse during playback, boosting low frequencies and attenuating high frequencies back to their original values. The attenuation of the high frequencies reduces high frequency hiss and improves the signal to noise ratio which in turn improves the dynamic levels of the recording.
But there’s more…
A phono cartridge and stylus comes in two varieties, there’s Moving Magnet or MM and Moving Coil or MC. A phono cartridge is actually a very small electric generator and it works by the needle or stylus riding in the analogue groove of the recording, tracing the mechanically recorded vibrations which in turn cause the stylus to move or vibrate. The opposite end of the stylus has either a magnet or a set coils mounted on it. If it’s a magnet, the magnet is suspended between a set of coils and if it’s a set of coils, the coils are suspended in a set of magnets. So, as the stylus is vibrating as it traces the mechanical grove, the coils and magnets attached to it generate a very small electrical current. The phono pre-amp steps up this small voltage to a line level signal where the pre-amp can then control and send to the amplifier.
So, the Phono pre-amp is working as both an equalizer and a type of amplifier or electrical transformer to raise the phono cartridge voltge/current.
Phono pre-amp technology is quite mature at this point in time. The RIAA EQ curve is also very well understood. Most any phono pre-amp that you buy today is going to work quite well. You do want to make sure that if you use a MC type cartridge your phono pre-amp is one that will work with an MC cartridge. An MC cartridge can be more sensitive than a MM cartridge the result being the retrieval of more “detail’ from the analogue recording. But, an MC cartridge generates a smaller voltage and requires a phono pre-amp that can step up the lower current level.
Because the vinyl/analogue playback technology is more or less “fixed” at this point in time, a lower cost phono pre-amp will do as good a job as a more expensive unit. The more expensive units generally have been built using closer tolerance parts resulting in maybe a little better S/N ratio or they have some flexibility in cartridge capacitance/impedance matching and the ability to use MC or both MM/MC cartridges.
Hope this helps.