Vandersteen Quatro / Model 5 Crossovers

I assume you are referring to the external high pass filters? These are different than the crossovers internal to the Quattro/5A. Both have 9v batteries. The external high pass filter battery is very straighforward to change as described above, and with a lithium replacement will probably last as long as you own the speakers. The crossover battery requires removing the amp from the speaker, and while a bit more time consuming is also straighforward.

These are very high quality electronics designed specifically for their application. I don't recommend trying to work around these. Even if it works, you are loosing an important feature of the Vandys in keeping capacitors formed and sound at its maximum quality even when not used for long periods.

Part of the cost of your Vandies was due to those very cross-overs your thinking about replacing. My suggestion; don't do it.

Awful idea.

Crazy bad move
Ist the 9V Batteries are easy to remove and replace
I did a pair tonight in 25 min.
2 pieces of about an inch each of 3M double stick tape,
2 GE 8 In thin type Cable ties and a good iron person are all you need.
The battery Bias is there to keep the Cap formed and sound their best for years, Lithium type 9V over 10 years.
Its the simplest x over known done trick style.
Adding something more complecated will only sound worst especially sporting Op amps in your signal path.
The X5 is exactly what you want for performing a Phase and time correct Simple 6DB High pass and the best sounding.
Please let me know if you have any questions
Best Johnnyr