EQ isn't going to give you more power, you'd need a bigger amplifier for that. The HA-SZ1000 is actually a very low-power (16 ohm, 108 dB/mW) set of headphones; those are almost as low-power as you can get. If you would be willing to describe exactly what you're trying to accomplish, perhaps we can guide you to a simpler solution.
For example, EQ is typically used when you don't like how your headphones sound. Are you looking to change the tonal balance? In what way? How does a +/- 15dB EQ not meet your needs?
Home Desk ~ MB 3.3 Portable • Questyle CMA400i (ASIO) • Sennheiser HD 660S (balanced) / Audeze EL-8 Closed Back / Fostex TR-X00 Ebony • Teac AI-101DA • Jamo C93 + Dayton Audio SUB-1000
Work Desk ~ MB 3.3 Portable / Tidal • SMSL SU-8 v2 • Nobsound NS-05P • THX AAA 789 • Sennheiser HD 58X (balanced)
OTG ~ FiiO M11 • Audiofly AF180 / B&O H6