New power amp or use Pioneer SC-25 as power amp

Just purchased the Sherbourn PT-7030 HT pre-amp. Emotiva says I will have trouble using my Pioneer SC-25 reciever as a power amp, due to the volume control circuits in both units (unwanted noise). I'm wondering if there is a way around this (can the Pioneer volume control circuit be disabled) or do I really need to use a power amp. I did purchase a UPA-700 amp from Emotiva also, just figured I'd return it if the Pioneer worked fine. Pioneer rated at 140 watts 2 channels driven, the Emotiva rated at 80 watts all 7 channels driven. Any help or ideas would be greatly appreciated.

Thanks Ron Greenlee
I think Emotiva may be right. The analog line inputs probably utilize the Pioneer's volume control and I didn't see any other Main In inputs that would bypass the volume control. The bottom line is you can still try it and compare it to the results with the UPA-700. I'd be very surprised if you don't hear an improvement with the Emotiva amp and it's just a better hookup situation, so if it were me I'd look to sell the Pioneer to offset some of the cost unless you really don't hear any improvement. Best of luck.