High pass on a GK MB200 or Ampeg SVT-3 Pro

[audiomitch]

My question has to do with using the preamp output on either of these heads (or actually bass heads in general). My scheme is to use a more powerful power amp as a "boost" in loud situations. In those instances, I would use either the GK or Ampeg strictly as a preamp feeding the new power amp. Does anybody know if either of these heads have a high pass filter on the output of the preamp? Or would I need to find a power amp with a cross over to prevent speaker "thump"?

Thanks in advance.

[prd004]

The SVT-III does not