Yipee ! A japanese Ibanez PQ9 at home, received today !
The honk I like is definitely between 600Hz and 800Hz (remember that medium 720Hz boost in TS808 and other TSx ?)
Schematic can be found there (OK, it’s not exactly the PQ9, it is related to PQL which has a Q-width knob … and btw, I love Dirk Hendrik’s web site) : http://www.dirk-hendrik.com/ibanez_pql.pdf
IT11 Audio Web Site