I love my JTV-89F. It's one of the best guitars I ever had. But, IMO, EMG active pickups are the best. I use EMG 81 and 85 and they sound great. So I decided to install those in my Variax JTV-89F.
After searching the Internet I could not find any source of reliable information regarding this topic. So I decided to share my experience.
I made a video documenting the process. You can find it on Youtube.
!!! WARNING !!! If you do this, you'll void your guitar warranty.
After installation all the Variax models are working perfectly. Also tuning and custom tuning.
Issue #1: The EMG pickups do not allow to split coils and the Variax uses a 5 way switch. While in magnetic pickups mode, position 2 produces the same sound as position 1. And position 4 the same sound as position 5.
1 = Bridge
2 = Bridge
3 = Bridge + Neck
4 = Neck
5 = Neck
When you activate the modeling mode, all the positions continue to be independent, as in stock mag pickups.
Issue #2: When the active pickups are powered, the volume control acts almost as an on-off switch. At 1/5 of a knob turn you start to hear sound already at almost 80% gain. Bellow 1/5 of a turn, no sound at all.
Issue #3: Tone knob seems to produce no noticeable effect.
That's it. To me, now I have a perfect guitar. I don't use much the tone knob, and I can control volume with my volume pedal.