Classe CA-101 or CA-200 with a passive preamp

I have a passive preamp with a Classe CA-101 amp which drives my Totem model 1 speakers ,I have money to upgrade to a CA-200 which is an older model but with more power does any body have any referance with both of these amps or an opinion? THE CA-101 sounds great with this setup but I need a little more volume ,also I am using a 75K ohms pot should I change it's size to 50k ohms ?
If you buy another CA-101 , you can flip it to mono and have 2 mono blocks at 300 watts per.
I would agree with Darrylhifi if you were to change amps though I would suggest vertical bi-amping instead of running them as monoblocks. But I don't think a more powerful amp is going to make a huge difference. Sounds like what you need is more gain so a pre-amp would be the place to get that. There is usually a 10 to 20 dB gain in most pre-amps. That will give you volume.