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.
1. Don't use Metal tapes
With metal tapes the head wears out 3x faster than with regular Type 1 ESPECIALLY on Nak decks.
2. I don't know the precise hours but with Metal tapes you can wear it out within probably 1.5years or roughly saying 5...6000 hours just like a cartridge life. Otherwise it would last much longer.
Don't worry Inna. You'll know your heads are worn if, after cleaning and demagnetizing, and worse case, re-aligning the deck, it no longer sounds as good as the source material. I firmly believe that the rate of head wear is largely dependent on the quality of tape used.

I'd agree with Marak that the heads in bottom of the line decks of any make probably don't last more than a few years. I disagree that using higher quality metal tapes, like TDK MA or Maxell MX, accelerate head wear. If anything they prolong it. Using cheap tape requires more frequent cleaning of the heads. Good type IV (metal tape) is more uniform than its lesser cousins. It doesn't shed its particles as readily, and it is the grit of loose particles that contribute to head wear.

Nak addressed head wear by using dual capstan transports in some of their pricier decks. The "Asymmetrical Dual-Capstan Transport" contains a lifter to move the pressure pad inside the tape out of the way, so it no longer pinches the tape to the head. This reduces scrape flutter and prolongs head wear. I've had my 3-head Nak CR-3A since new in 1988 and it still works and sounds as good as new - using metal tape exclusively to archive hundreds of record albums. So if yours still sounds good, all I'd recommend is regular cleaning, and regular exercise.
Appreciate your responses.I use TDK and Maxell metal tapes for the obvious reason-they are so much better than other types.Rockvirgo,I am inclined to agree with you on the affect of a good metal tape.For the last 1.5 years and after about 500 hours I cleaned the head once, and it was absolutely clean-nothing.Another thing.Is it just me but I don't like Dolby C and use only Dolby B or nothing.I believe that Dolby C interferes too much and takes some sounds away along with the noise.
Wow Inna, 500 hours is incredible. I feel I'm pushing my luck if I wait 50. Nak recommends cleaning every ten hours.

Dolby C was relatively new on the scene when I got my Nak. The extra 6dB of published signal to noise ratio for C vs. B sold me. I record everything in Dolby C using TDK MA, leveling the hottest signal at a hair under +10dB and pre-adjusting the bias until I can't tell the difference between the source and the tape.

But yeah, sometimes at low playback levels I get the feeling I'm missing something. At normal volumes and beyond though, the sound comes into itself and becomes quite natural. Then I'm glad the tape doesn't sound too hot. Tell you what, I'm still so chuffed over the extended playing time of tape that I prefer it to spinning the original records. Along with the confidence that good metal tape imparts, it's just too easy.
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...