Yikes. There is so much crazy misinformation in this thread that it is scary. A little information is truly dangerous. First of all, Gyger is not out of business. They are a small company that has healthy sales and a niche that will keep them healthy for years. Phonograph diamonds are a tiny (no pun intended) sideline for them.
As to which diamond is what, the following is my distillation of what is found on the net and including a phone call to Mr. Wyndham Hodgson who told me he made the van den Hul diamond. Also AJ van den Hul’s own words in various interviews easily Googled.
1. AJ designed the vdH1 and vdH2 diamonds on the computer. But he still needs a partner to actually make the diamond;
2. He approaches Fritz Gyger (who else, anyway?) whose production equipment made from a “Meccano Set” according to AJ had a flaw in that it could not produce round phono diamonds. It made ovals, but AJ took advantage of this “flaw;”
3. Together Gyger and AJ developed the final version of the two diamonds, one radical asymmetrical and the other a conventional symmetrical design until it was ready for market;
4. Gyger beats van den Hul to the patent office and wins global patents for the Gyger 1 and Gyger 2;
5. AJ sues in Swiss court;
6. AJ in a compromise decision wins patent protection for all the globe except Switzerland. Gyger wins patent protection in Switzerland. Thus, the patent is SHARED. Gyger and van den Hul both may claim the design and use it as they like;
7. AJ needs someone to make his diamond. He finds Wyndham Hodgson who agrees. But Hodgson knows AJ can turn to no one else so gets a license agreement to produce the same two designs as the “Paratrace 1” and “Paratrace 2;”
8. Gyger diamonds are the one “real” versions as they are made as originally designed on the original equipment;
9. Van den Hul and Paratrace are made to the same design but are not quite “identical” to Gyger as anyone who views them under a microscope can see. They are not quite laterally symmetrical like a Gyger is, but they work and the tracing edges are where they should be;
10. Decca diamond looks like a Gyger 2, but it is a different size diamond block. It’s pretty huge in comparison to a Gyger 2, but otherwise appears to be made to the Gyger 2 formula. Could be made by Expert Stylus. Could be made by Gyger. The person to ask is John Wright if he would tell you.
11. Replicant 100 and all Ortofon Gyger diamonds are made by Fritz Gyger AG in Switzerland. Replicant 100, 110, 120 etc is all marketing bluster from Ortofon as is “FG70,” and “FG80,” etc. Gyger makes 2 diamonds with nominal dimensions. The S is 5/120 and the 2 is 5/75. As with any diamond, there are tolerances. Namiki’s dimensions for the Micro Ridge are given as r/R 2-3/70-80 microns. Gyger is likely truly the same way. Despite the specs, customers receive an assortment of sizes all compliant to a range. I suggest that all Ortofon might do is sort and grade what they get. They put the S with the 100 micron scanning edge in one pile and the 110 in another and so on. If you really believe they go through the time and expense. So a Replicant 100 is really a Gyger S with a measured scanning edge of 100 microns.
Gyger AG is not out of business. I order from them regularly.
I hope I have put some rumors to bed.
Needlestein