I know that the first generation Philips cassetes need new felt pads and I experienced that myself.
But now I found out that also the PDM cassettes make that anoying squaking sound. Are there people who have this problem with PDM?
Going to change the felt pads also for the PDM’s.
Are there more type cassettes known for the squeaking problem?
None of my PDMs have done that to me yet, but that doesn’t surprise me. I think these, too, were OEMed by Philips, so for all intents and purposes they are 1st-generation Philips tapes, just in a different wrapper with different graphics. The cassette-shell and slipcase molding is identical to the Philips tapes, right down to the font used for the embossed lettering, and they both say “Made in Austria.”
(Ever since the issue came up in connection with the Supertape SD90s over on the Type of blank DCC tapes thread, I’ve been making it a point to examine my assortment of DCC tapes more closely, and I’m pretty much convinced at this point that there were really only two or three actual manufacturers of DCC tapes, and they just OEMed them to the other brands with different silkscreening and shrinkwraps.)
Thanks for your reaction. I think that you could be right very well!
Although subjective, the recording ratings in the museum’s blank tape section differ from one 1st gen tape to the next, with the PDMs leading - actually what convinced me to get them.
If they’re all made from the same sources, where would/do the differences in quality come from?
The recording ratings are highly subjective, and not really based on any rigorously-applied side-by-side comparisons under laboratory conditions. As I understand it, it’s based almost entirely on reports from various forum users, and the DCC Museum guys themselves, and so there’s a fair bit of “take this with a grain of salt”, I think. Especially when it comes to tapes which may only have originally been available in certain countries but not others, and so would have relatively few users reporting on their performance or which the Museum guys personally had little/no experience with.
Also note that the PDM tapes have contradictory ratings of “good” and “excellent” recordings, and are both “rare” and “common”, according to the list, with a note that the 1st-gen and 2nd-gen versions look identical. Meanwhile, the 1st-gen Philips tapes are all rated “adequate/good”, while the 2nd-gen Philips are “good/excellent” – so if the PDM tapes are actually OEM’ed from Philips, then that wide range of ratings on the PDMs make sense; 1st-gen PDMs would be the “adequate/good” 1st-gen Philips tapes, and 2nd-gen ones would be the “good/excellent” 2nd-gen Philips tapes.
Unfortunately, the time to do a proper, rigorous testing of all of the different brands and generations would have been about 25 - 30 years ago, when all of these different tapes would have been easily available at retail and someone could have acquired a representative sample of all of them (say, a box of 10, then randomly sample 3 from each box; or, acquire 1 of each brand from three different retail outlets to help insure they didn’t all come from the same batch), and then put them all through their paces on a couple of different models of deck and recorded the results based on objective standards, such as the number of errors reported on the service-mode displays during recording and playback.
But of course, 30 years ago, there wasn’t a DCC Museum to do that kind of rigorous testing, and the internet was still kind of in its infancy and it probably would have been near-impossible to coordinate such an effort anyway, so… 
