I wasn't going to quote this, since it's getting even further outside the thread subject, but what the heck...Coffee Phil wrote: ↑27 Dec 2018 19:02:P Hi ,
I am having trouble parsing Vanakaru’s post. Most of what we think of as 78s are lateral cut with a wider groove than Lps. As you say the groove is V shaped and the same information resides in each groove.
Some records are vertically cut. Vertical cut records are also refered to “hill and dale” cut. The most common in the US are Edison diamond discs. They are laminated with playing surfaces made of a material similar to Bakelite and wood flour core. These are ~ 1/4” thick. The same stylus used for 78s seems to work well on Dimond discs. Pathe also used the “hill and dale” cut. I believe most Pathe records use a wider groove which was U shaped. I have one Pathe record in my collection. It is 80 RPM, hill and dale cut, and outside start. It is ~14” in diameter, so it just barely fits my turntable with an SME 3009 arm. It plays reasonably well with a 2.7 mil stylus. The material appears to be shellac, as most 78s, and is ~1/8” thick. I read that the approate stylus is ~ 4 mil, but they are very spendy so unless I acquire more of these I’ll stick with the 2.7 mil.
I have not yet seen a 1/4” thick Pathe, but have no trouble believing that they exist. Pathe did a lot of variations such as outside start, inside start, and they may have even made some lateral records.
I really don't think 1/4 inch Pathes exist, I've never seen one or read about one. They are solid shellac records, unlike Edison Diamond Discs. The recommended stylus for a vertical Pathe is a 7 mil or so. If you can track the wide, shallow grooves of a vertical Pathe without skating, you can get acceptable playback without one - as you said, the styli are spendy. Yes, Pathe made lateral records, the 'Actuelle' discs dating from about 1920 or so, including electrical Actuelles from 1926-27 onward.
The 20 inch Concert Records that Pathe made are one of their most unusual products. https://www.youtube.com/watch?v=wvbkSvGMJSQ