http://www.ebay.ie/itm/200660044657?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

I'm sure you meant RX705

I have managed to sort out the gremlins on this little Aiwa. As i thought, the tape detection switch needed slight adjustment. It wasn't making proper contact, which was causing the tape to stop. Very simple fix. As regards the left headphone, the distortion was caused by the grill being slightly loose. This was causing the clear film over the driver to vibrate. Again, an easy fix.

Works perfectly now. I done some research on this one. Has a HX head i believe. The belt on this one is so easy to replace. Why did aiwa make belt replacment so difficult on some of there jx series? The internal layout of this model is far more repair friendly. 

So now that you've fixed these issues are you going to pull it from eBay? Is there any reason why you wouldn't keep this in your collection?

How are you not able to confirm that it has a HX head? If you can see inside the cassette deck and view the head, then it should be apparent that it has a HX head from the shape of the contact surface.

The RX705 is based on the ALP tape transport, and these are some of the easiest to work with internally. This tape transport is not exclusive to the JX series, as it is found on the PL, PX, JL, JX, RL, RX AIWA models from the late 80s to early 90s. I agree, models other than the ALP type can be quite difficult to repair.

The only real weakness with the ALP tape transport based models is that the majority of these were produced using capacitors which had a tendency to leak.

Two grooves would definitely indicate a HX head. Not sure if it is an amorphous head though. Probably just a standard permalloy head "Narrow Gap HX Head" or "Permalloy HX Head". This could be confirmed from a sticky label inside the door or the user manual.

Yes, not all the ALP transport models had bad caps. It just depends on how lucky you were, but the majority I have seen do. For example, I have a PL70 and it is in perfect condition capacitor wise. On a positive note, virtually every ALP transport AIWA I have seen, still have their original belts.

By that I am supposing you mean that the grooves are cut perpendicular to the direction of tape travel. If so, then it's a HX head.

If they are cut along the direction of tape travel, then that's a type of design I've never seen before on an AIWA walkman. I've seen that style of design on Panasonic heads.