Cassette deck head wear


Forgive my question, but how do you estimate the head wear more or less precisely(+/- 10%)? My Nak682ZX sounds no worse than before, but the playback head does not look exactly new? How many hours do they usually last anyway? I use only Metal tapes.Will appreciate your responses.
inna
You push it to +10?And no distortion? I do +7 or +8.I also found out that TDK sounds slightly better than Maxell and hear no difference between TDK MA and TDK MA-X though the latter may be a little better mechanicaly.I have tapes that have been played at least 50 times;no sound degradation.Have you ever tried TDK MA-XG? I've got a few sealed but just can't justify unsealing them for now.
agree that Dolby C breathes & pumps levels excessively

don't forget to degauss those heads & capstans, even though you're not having to clean very often
Using TDK MA, the average level on rock rides around 6-7. I'm happy with the level so long as the ten bar only momentarily flashes. I haven't tried the MA-X's rationalizing that my deck, the least of the three-head designs, would not take full benefit from their higher performance.
I prefere to use no Dolby on my RX202 deck and I'll try to use Metal tapes on that. Mine records near-perfect on Type1 tapes and I believe that it will be perfect on Metal ones. Years back I used cheaper tape deck that were realy affected by Chrom or Metal tapes and for my newly-acquired Nak one year ago I decided to use only Type1 normal bias tapes. What is the bias settings you need to use for Metal. I have on my nak switches for type1, type2, type3 and type4.
Considering the snail speed of cassette tape vs. studio (1.825 / 15 ips) I'd really not worry...

I never use Dolby A,B,C,HX etc etc. What is critical is head/tape path cleaning and degaussing. If the machine has the capability, bias and level adjustments are important.

The best tapes I've heard on my (mature) JVC 1050 are Maxell XL II-S...