Hi everyone. It's been a few years since I was last here. My Walkman collecting took a bit of a break when I finally got a perfect cond. WM-DC2 and had Marion fix it. I am now back to collecting, with a focus particularly on obscure models (working or not) that have particularly good heads. I've found a lot of conflicting information though about the quality and type of heads. Their strengths and weaknesses, so I thought I'd come back and ask the pros. I am also traveling to Japan soon and might get a chance to pick something up, although I won't be going near to Tokyo or any other major cities except Nagasaki (and the purpose is not Walkman collecting) so let's see. ------------------------------------------ The purpose of this thread is to hopefully great a "quick cheat sheet" of the differences, strengths and weaknesses of each cassette head used in Walkmans/other cassette devices. So far I have determined the following (please correct any mistakes): Amorphous - A head made with much more durable materials that not only provides a clearer and more accurate sound but generates less interference in the audio. Not all the below heads are amorphous, for example some HX heads were not actually also amorphous. Used in Aiwa JX707, RX70 and PX1000. EX - EXtended Head, a slightly better quality head with extended dynamic range compared to traditional "cheap" no-name heads. Generally all permalloy quality. HX - Hyper-eXtended Bass Head, uses a slightly peaked contact surface to achieve better contact and reproduction of low bass frequencies. HX only used in Aiwa PL303, WR707, PL777, PL707, P705 and P505 Mk2. HX Amorphous used in JX3000, JX2000, PX303, PX505, PL50, RL50 and RX50. HX Narrow/Fine Gap - A further refinement of the HX bass head where they actually combine all 3 qualities: Amorphous, HX and Narrow Gap. Used in Aiwa PX-303, PL-55 (v1.0), PX20, JX505, JL505 and TP38. Generally the case if the model has a max frequency response higher than 15kHz. Laser - Propertied (by Sony at least) to be the most resilient to wear of all heads and used in eg. Sony WM-DC2 and D6C. EDIT: Updated and fixed some mistakes. EDIT 2: Added some more info into this OP.
Check this post on the Personal Hifi Blog: https://personalhifiblog.blogspot.com/2011/06/is-it-all-in-your-head_1.html. Per the article, amorphous is not related to any azimuth settings; it refers to the material of the head, stronger for less wear and tear. Perhaps you can update the first post with your findings, mixed with Julian's?
Want to make a couple of remarks: 1. HX Pro has nothing to do with the head, it's an electronic circuit that varies the bias with signal level in order to increase the dynamic range that can normally be achieved during recording. 2. Azimuth being adjustable or non-adjustable (as @Emiel has already pointed out) has nothing to do with head type. Generally speaking, older units have adjustable azimuth (some autoreverse even having dual adjustments), while newer ones typically have fixed azimuth. 3. The gap of the head is what determines the frequency response: the finer the gap the more extended frequency response will be. Amorphous heads are not always fine gap (example WM-D6C) and fine gap heads are not always amorphous (most of SONY WM-EX series). Look at the frequency response specififed in the service manual. If it's higher than 15kHz, it is fine gap although don't think SONY ever marketed this aspect. Then even other companies (like Panasonic with early RQ-S series) didn't always write "fine gap" on the case, even when there was such head installed.
@givemeyourwalkmans : nice update of the FP. I forgot to mention: in my signature there are links to the Dolby C overview and DD Genealogy. Both overview contain head info for some models, like some D6C models amorphous, some not, etc.