Onkyo 809 receiver: using as preamp with Bryston amp

I've been using  Onkyo 809 AVR  for some time in  5.1 system, 
HSU package, VTF 15 sub. 

I've gotten Back into vinyl now. And itching to get a dedicated amp. 

Would it not be recommended to use onkyo pre-cut to say  nice Bryston amp for 2 channel sound? 

the vinyl is only going to sound as good as the phono pre-amp--i'm not sure how good the phono out on the onkyo is, but i'd guess that a separate 2 channel pre-amp with a high-quality phono section would sound better, especially with a high-quality dedicated amp like a bryston.