I sure hope my WEE will be of the domestic variety.
If the WEE has similar gain to the SRD-7Professional then your Accuphase should be just fine.
I use a SRD-7Professional with an Aleph J and a passive preamp. This combo has enough gain for my tastes with all earspeakers except the Sigmas. The Sigma seem to need more voltage gain than any other earspeaker I've tried but it is only a problem on very quiet recordings.
My Aleph J has 20dB of gain. http://www.firstwatt.com/prod.html
Your Accuphase has 28dB of gain. http://www.accuphase.com/cat/e-406ven.pdf
If you were to pair a unity gain amp (ex. First Watt F4) with a passive preamp you might not be happy with the end result.