I recently bought an AKAI GXC-570D cassette deck,(made in japan on july 1976)but I find that when I play LN(typeI),Chrome(typeII) tape,the treble seems a little subdued.Otherwise it sounded great,very warm.I don't very know why,so if you knows the reason, please tell me why and how can I solve it.I can also provide you this machine's service manaul if you need.

Thanks!!