Regards, Nandric: Audio Technica nomenclature is simple. Almost. In the instance of the TK(x) carts, the first production might be called "big-block" carts, they are most easily described as rectangular. This would include the TK7E (elliptical) and TK7SU (Shibata). Any revisions would have the added "a" after the designation, think "Mk 11". The TK(x)a carts are on the AT120 design, one that continues with the contemporary AT150MLX, 7V and 150ANV.
If you go to: http://www.turntableneedles.com/AUDIO-TECHNICA_c_25165.html and scroll to near the bottom of the page, you'll find the styli for both the TK7LCa and just beneath it, the TKN22 for the earlier design. Click on the image & then hover the arrow over the pictured stylus & it'll rotate. A really useful feature.
Pay attention to the "plug", the feature that inserts into the "socket" at the bottom of the generator. The early iterations have a round plug, the later design is rectangular. They are not cross compatible. Also, the bottom of the generator is angled, there are differences here, too. Other considerations can usually be overcome by a determined man wielding a hobby knife.
If your cart looks like this:
http://www.ebay.com/itm/AUDIO-TECHNICA-SIGNET-TK7LCA-CART-GENUINE-AUDIO-TECHNICA-SIGNET-TKN7EA-STYLUS-/160876230864?pt=US_Record_Player_Turntable_Parts&hash=item2574f878d0
then you & Henry can resume negotiations.
Peace,
If you go to: http://www.turntableneedles.com/AUDIO-TECHNICA_c_25165.html and scroll to near the bottom of the page, you'll find the styli for both the TK7LCa and just beneath it, the TKN22 for the earlier design. Click on the image & then hover the arrow over the pictured stylus & it'll rotate. A really useful feature.
Pay attention to the "plug", the feature that inserts into the "socket" at the bottom of the generator. The early iterations have a round plug, the later design is rectangular. They are not cross compatible. Also, the bottom of the generator is angled, there are differences here, too. Other considerations can usually be overcome by a determined man wielding a hobby knife.
If your cart looks like this:
http://www.ebay.com/itm/AUDIO-TECHNICA-SIGNET-TK7LCA-CART-GENUINE-AUDIO-TECHNICA-SIGNET-TKN7EA-STYLUS-/160876230864?pt=US_Record_Player_Turntable_Parts&hash=item2574f878d0
then you & Henry can resume negotiations.
Peace,