pre amp suggestions

Thanks very much but I tried before but this rowland amp doesn't seem to have any adjustments. I spoke to Jeff Rowland and he said that this model didn't have the adjustments like the later ones. In the past I had the sevens and they had the adjustments as described. You all are correct I believe because as I think about it the amp seems to be the problem.

A few months ago a friend and I adjusted the impedance and it sounded best at the factory setting I think. However it sounded best at it's current setting, then we tried adjusting the gain and removed the module but there wasn't any adjustment controls and that's when I contacted Rowland and was told that the gain could not be adjusted on this particular series. I guess that I would have to start looking around for another power amp e.g the Rowland 8t, krell evo 402 or some other s s amps. Feel free to make suggestions. Currently the system sounds ok but to me and some of my friends it's a bit dark and I believe it's from the Rowland.