I use amp modelers often these days and one problem with some of the patches is not enough gain when wanting more distortion. After trying a few different power boosters, I like the RC Booster the best but not quite enough gain for an amp modeler patch I like to use for solos.
I asked Xotic Custom Shop if it is possible to add 10 dB of gain (on a pot) to a RC booster. They did so and I must say the gain addition is perfect for the amp modeling patch! With the gain addition, the low frequencies were too forward but no problem since the low frequency pot on the RC Booster allow me to roll out the low frequencies to taste.
As to headroom, no problem but as to get even more headroom, the guys sent me a connector that allows for two 9 volt batteries as to jump up the voltage to 18 volts!
I am very pleased with the RC Booster!
Jay's unit is specially modified to accommodate 18 volt.
The current production model can only take up to 15vdc.