determining condenser impedance or variable impedance driver ?

[petemoore]

  IIUC Correctly I want the output impedance of the driver to be lower than the condenser impedance.
  I have not discovered any way to determine the condenser impedance...so I don't know what the needs of the driver are.
  I dialed the Accutronics number, woke some girl up, verified I'd dialed the exact number..
  Sent an email with every available tidbit of info [brand, patent #, various ink stamped #'s...
  Tank's input condensers measure 221 and 250 on the ohmmeter, DC.
  I'm using a short and a long, each are two spring units.
  Stage center Reverb driver [isn't there a way to strap an LM386 as final drive for driver output?]
  Seems a bit weak, I think the driver isn't sufficient to power the condenser.
  Good news is both tanks are working.