"Bi-fet" op amps and "Bi-polar" op amps. Same thing?

[The Iron Chef]

"Bi-FET" op amps and "Bi-polar" op amps. Same thing?

I have 6 ad544kh "Bi-FET" op-amps.  (http://www.datasheetcatalog.com/datasheets_pdf/A/D/5/4/AD544.shtml I'd like to use them for some thing and I thought that I might should  try to substitute the jrc4558 op amp in the very nice AMZ Overdrive Pro that I made last month. It appears to me that I can use them. What differences should listen for if they do work?

tia
Keith

[Sir H C]

Different, the BiFET have a very high input impedance, the bipolar are usually a lot lower input impedance (because of base current).