How many grooves are on a cd

The combination of the recorded dye groove with the reflective layer modulates the reading laser in the same way as the injection moulded pits and lands and the reflective aluminium layer of a CD -ROM. In a recordable CD each dye gives the media its distinctive look depending on which metal is used for the reflective layer; cyanine blue dye appears green on gold media and blue on silver media; phthalocyanine clear light green dye appears transparent on gold media, but light green on silver media; azo deep blue has developed into different shades of blue, the original being a deep blue, and the more recent Super Azo a brighter shade of blue.

Because the dye layer is applied so thinly in recordable DVD the type of dye used on recordable DVDs is not easily distinguishable. However, manufacturers of recordable CD and DVD encode information about the type of dye in the polycarbonate layer.

The CD and DVD burners use this information to calibrate laser power, and with suitable software the information can be read by users to more accurately describe aspects of the disc itself. This tool allows users to view information such as dye type, disc manufacturer, capacity, write speeds and media type. Rewritable discs are erasable and can be rewritten, albeit a finite number of times.

The recordable layer is made of germanium, antimony and tellurium. A laser is used to heat the surface to two set temperatures. The higher temperature is known as the melting point approximately degrees centigrade , while the lower level temperature approximately degrees centigrade is described as the crystallisation temperature.

Heating the disc, and controlling the cooling rate, produces a track of amorphous or crystalline areas. Earlier rewritable discs and drives could only be written at relatively low speeds and this was encoded and implemented in the first generation of drives and standards.

More recent developments have provided a mechanism for burning data onto rewritable discs at a higher speed. Does anyone know definitively what the standard is?

Any help would be appreciated. There is no definitive 'standard'; manufacturers can vary the pitch depending on how much data they hope to fit on a disk.

There is probably a maximum allowable by the spec. There is a digest of these specs I once had, don't remember where I got it. Sorry if this isn't so helpful.

Dan Miller w. I didn't think CDs had a spiral groove. But I could be wrong. CDs do have a spiral groove. Is 'groove' the right word, anyway? At 45 rpm they hold around minutes per side. Records come in three standard sizes: 7-inch, inch, and inch. At a certain point, records can become cramped with grooves and have to expand in size to accommodate the extra music play while maintaining the quality of the audio. The accompanying album covers of 78 vinyl records are often worth as much or more than the actual record discs.

But reading their FAQs, it does not appear they will ship those old records back to you. Vinyl records also come in three standard diameters: 7-inch, inch and inch. These discs can only record data once and then the data becomes permanent on the disc. The data on a CD-RW disc can be erased and recorded over numerous times.

How many grooves are in a 33 rpm record? How many grooves does a vinyl record have? How many grooves are there on a CD? How many grooves are cut on a normal LP record?

How many grooves are there on each side of a 45 rpm record?