I just got the kit, it's just beautiful!
With good capacitors, the pedalshield can work with an active guitar bass?

Yes, you can get a better bass response by using bigger capacitors.

In the schematic there are 6 caps (rectangular shape, red-brown color) which remove the excess of bass:

• C1, C4, C6, C7, C10 and C11 are 100nF and remove the harmonics below 16Hz (you can use the Okawa tool to calculate this frequency using 100K resistor and 100nF cap).

This is not bad for a bass guitar, but If you want to remove less bass harmonics you can use a 470nF caps and you will only remove the harmonics below 3Hz.

A folk asked me by email about a recommended cap for this. I have used the 0.47uF Panasonic ECQ-V1H474JL (which are out of stock in Mouser right now) they are not very expensive, there are other alternatives which look good and available:
- ECQ-V1J474WJM
- ECQ-V1474JM

If you go Panasonic and film for 0.47uF you will probably go right.