Mono cartridge classification

The only difference I know of between Mono records is early mono's, pre Stereo & the 60's the groove profile is differant than they are now and when stereo was introduced. So the needle profiles are differant. I have not had any problems with what I use but some feel there is a differance in sound between them the two. There are threads here on the subject.

Dear Pkemery: Why don't you ask Ortofon directly? Ortofon was your ask source, right?

Regards and enjoy the music,
Raul.

Oooh, boy. This is a pretty complex area you're getting into. Google will be your friend. The wide range of contradictory information you find will be your enemy. I'm just learning about the world of mono myself, so take everything I say with a grain of salt. And I hope those more knowledgeable will double-check me. But here goes:

That symbol you're talking about is almost certainly the symbol for micron (also called a micrometer). The thing to remember is that 25.4 microns equal 1 mil. Generally, you will see today's typical elliptical stylus dimensions stated as .3 mil x .7 mil. These serve well for playing mono records. When you see a stylus specified in microns, just convert it.

Despite the fact that I said a .3 mil x .7 mil stylus is fine for mono records, many people maintain that it is best to use styli that are similar to those used at the time the recording was made. VERY GENERALLY speaking, records that are not labeled either "mono" or "stereo" are mono recordings. These, according to some, should generally be played with spherical (aka conical) styli of 1 mil (25.4 microns). If the record is labeled "mono," it was probably made during the early stereo era. Since the record grooves were narrowed at this time, it's GENERALLY best to play these records with spherical styli of .7 mil.

Modern high-end cartridge makers like Lyra are today making very expensive mono carts and maintain that variations of modern fine-line styli are best for playing mono records.

Also be aware that cartridges that are sold as mono carts actually do produce a mono signal (Denon DL-102, Grados). But some are called mono only because they have a bigger spherical/conical stylus appropriate for mono recordings——BUT their output is stereo (Ortofon D25M, I think). The signal must be summed by a mono switch on a preamp, by wiring the cart for mono, or by using a double-Y connector to sum the signals.

Keep in mind that in discussions of mono, the term "LP" is used to refer to 33-1/3 RPM records, as distinct from 78 RPM.

If this isn't confusing enough for you, I invite you to hit Google. A very good summary is offered here:

http://www.esotericsound.com/CartStyli.htm

There's also a mono forum at Lenco Heaven:

http://www.lencoheaven.net/forum/index.php?board=18.0

Hope this helps, but I'm guessing it might not!
-Bob

Sorry. The first sentence of my fourth paragraph, above, should read:

"Also be aware that SOME cartridges that are sold as mono carts actually do produce a mono signal (Denon DL-102, Grados)."

-Bob