[TIMTAPE]

Originally Posted by knobtwiddler

Thanks.

I have a couple of full-track azimuth adjust tapes.

When it's only transferrring old recordings these reference tapes are of no use. Each old cassette recording we want to transfer is now our "azimuth adjust tape".

Originally Posted by knobtwiddler

My feeling has always been that unless the machine has PB azimuth as a design feature, I am risking curling the tape (as well as loosening the screw / nut over time, which is a concern, considering the carriage moves up / down quite a lot).

Not really. Standard cassette heads were designed with a tape guide fixed to only one side. The azimuth screw mostly adjusts height on the opposite side of the head. So with azimuth adjustment the guide height should only rise or fall minimally. As James says, often the azimuth deviation adjustment needed is only small re nominal. But yes a worn head can cause problems if the adjusting of azimuth tends to lift the tape out of the head's wear groove, making the audio worse, rather than better. But what are we doing transferring valuable tapes with a worn head? The head face should be pristine.

Originally Posted by knobtwiddler

My tapes are important to me, but I am concerned about getting a Nak, as we're at the top of the market for such things, and it's very easy to get straddled with a dog (you don't see heads under the microscope in the sales photos!).

Yes and when photos are presented in online adverts they are often poor in showing the head's real condition.

Originally Posted by knobtwiddler

The plastic wheels that adjust the head make me nervous as well - after 30-40 years, how tough will they be?

The Nak head mounting and adjusting mech is delicate but if treated with care it's fine I've found. I broke a tiny plastic mounting part in a Nak once, and it taught me to be careful from then on. The small white plastic adjusters I've never had a problem with but the key obviously is being careful.

Originally Posted by knobtwiddler

My Technics has a specially-designed Record azimuth screw, but the PB one isn't easily accessed.

I have a Sony ES deck. Nice little machine but access to the repro head azimuth screw is poor, and mods to fix this would be difficult. So the Sony is rarely used. Similarly the Tascam 122 MK III is a great deck in many ways and many archivists use them, but access to the playback azimuth is very poor.

Originally Posted by knobtwiddler

I also note that the screws used to retain head on many decks have quite coarse threads... I would've thought you'd want a very find pitch one. It does seem to me that it could be quite easy to skew the tape if being clumsy.

Yes a finer threaded screw would often help but I've not felt the need to make that particular mod. If the azimuth needs to be adjusted further than usual obviously we take more care. For those who mindlessly adjust the screw so far out that it completely falls out, and does other damage, what can one say?

Originally Posted by knobtwiddler

It also seems to me that the Nak systems (particularly elaborate automatic ones) have plenty of scope for maintenance issues after 30-odd years, mechanically and electronics-wise.

Yes that applies to old gear generally but tape and video decks are complex beasts and maintenance hungry, as they always were, but 40 years on, the maintenance issues have usually multiplied. Some of the top decks are beltless which saves on maintenance but there will still be issues, just a few less of them.

Originally Posted by knobtwiddler

edit: and another thing: the only Nak with Quartz lock is the Dragon.

The quartz lock is good but only covers the capstan motors. It doesnt cover mechanical issues.

Originally Posted by knobtwiddler

The main tech for Naks in Europe now refuses to take on Dragons, as he says 9/10 have worn heads.

Those heads have been wearing for a long time now! Worse, the Dragon's special 3 track play head, essential to the operation of the auto azimuth system, is basically made of unobtainium.
Knowing this, I'd never buy a Dragon for the auto azimuth feature which actually has its limitations even if working at its best. Richard Hess says it is very slow to react, and only works if the right track from which it gets its information carries a good, strong signal. Not good for archival tapes in all sorts of condition.

Having said that, cassette heads can be relapped, including the special Dragon repro head. I wonder if the fellow in Europe relaps them.
Nak classic heads are actually easier to relap than most other cassette heads because they have no attached guide in the way. All my Nak record or play heads I've relapped, some more than once.

For me one of the much more affordable dual capstan Naks is a more realistic purchase for high quality transfers. Of course they need to be in good working condition.

See photo of a mod I made to another Nak 480. The plastic azimuth adjuster already has a hole moulded in its centre. I found a piece of wire which fitted snugly in the hole and allowed me to make the front panel adjuster without much effort. A piece of wire, a small plastic knob and some careful filing of a few deck parts to allow clearance. The exposed adjuster is vulnerable though. I should fit a shroud around it to protect it from accidental knocks.

Note too another unusual Nak feature: the white wheel to the left allows easy head height adjustment. Not needed as often as azimuth but good to have. I made a felt pen mark on the screw at the 12 o'clock position to indicate standard height.