takamine+lr baggs external preamp

[svetlana]

I have a 132sc takamine classical on which the preamp is dying (very low output, eats batteries like crazy) If the preamp dies completely, would an external preamp like the gigpro work, or does that unit need an already amplified signal to function correctly?
If so, would it be preferable to disconnect the failing takamine preamp, rather than use it in combination with the gigpro?
Thanks