My last grow took 14 weeks of bloom.. but I use LED.

As far as I know the problem with trichomes turning amber under LED is the fact that there is not enough UV.

My 190w LED light has 1 x UV and 1 x IR but I think it might need a bit more. I started using 260w of CFL (4 x 65w) and I have noticed the trichomes becoming amber quicker.

I would expect the HPS to give off much more UV, but Kalidank1 is very right. Some strains just take longer.

Go with more Indica dominant or try some autos, they will be done faster. Just had a chat about my waiting time on my blooms with someone and that was the advice I got.

Take care dude and be patient !

S.L.