Using "pre-outs" of an integrated amp provide sound quality equal to a separate pre-amp?


Will using the "pre-outs" of an integrated to drive a basic power amp provide sound quality EQUAL to a separate quality pre-amp?? 

I have read that many pre-outs are just "op-amps" that channel an output signal to the amp, but  are not equal to the output stage of a separate pre-amp, and therefore limit or hinder or limit the performance  of the basic power amp.   .

Trying to determine if it is worth it investing  in a separate pre-amp for a BAT VK-200 amp

Would a quality pre-amp provide 15% to 2o% better sound??    Thanks


sunnyjim
An integrated amp is essentially a preamp and power amp sharing the same box so if its of good quality there is no reason why you couldn't use the integrated internal preamp (preamp outs) to drive your Bat power amp. One time my preamp needed new tubes and was temporary out of commission so I used the preamp outs of a Harmon Kardon receiver to drive it with surprisingly good results. But only you can judge the end results and whether you need to move ahead and buy a dedicated stand alone preamp.
Separates is the best way to go in terms of sound quality. I have five monoblocks, one for each channel and I couldn't be happier.