Preamp or Active DI Box w/ Piezo Pickup?

[jthuma94]

The sound guy for our band wants to run my bass through an active DI box (because we have one) instead of a preamp (which would require purchasing one). Is an active DI box an acceptable substitute for a preamp? How do they differ?

[Bob Gollihur]

Just check the specs, some DI boxes do have an input impedance of 1 megohm or higher. Provided the pickup you use has a decent signal level without a preamp, going direct with a DI should be fine.

A preamp usually can offer

• impedance matching
• signal amplification
• equalization (tone controls)

and more advanced units may have other useful functions/facilities such as

• phase reversal
• DI output
• high pass filter
• multiple channels
• etc......

Choosing a preamp or just using a DI box depends on your specific needs.

[jthuma94]

Thanks Bob! Couple more questions...

I am using a K&K Bass Max pickup and the DI box has an input impedance of <250k Mhz... This should be okay? Is an active DI necessary if the board has phantom power? The only difference as I understand it is that the active DI has a built in phantom power and a passive DI does not... the active seems to have better frequency response too but that may just be the two I am comparing.

[Bob Gollihur]

The Bass Max is usually more tolerant of lower impedances due to its very hot output - if it sounds good, it is good. And the phantom power should have no real impact on the sound, it's probably the sonic difference of the two units you're comparing that is making one sound better to you.