Is a separate phono preamp worthwhile?


Hello all. First post (cherry) for me. Longtime reader.
I have a McIntosh MA8900 integrated with a Ortofon 2M Black for vinyl playback. I'm using the MM input and I'm generally satisfied. I've heard some pressings that sound amazing , so I know it's capable.Would a purchase of a dedicated phono pre add to the performance or should it wait until a future replacement of the cartridge with a probable MC in the future.I mainly listen to prog rock, metal, some jazz , psych and of course classic rock.Thanks. Greg

gjohns
I used an EAR 834p with my McIntosh C42 and that was much better than the internal phono preamp. When I upgrated to the C70 I tested for a couple weeks before concluding the C70 phono was better sounding than the EAR. Whatever that anecdotal evidence is worth to you.
Separate phono stages  are a big improvement to built in phono stages for the same reason as power amp and pre amp are superior to a receiver.
There are preamps that were designed for vinyl based systems. The Audio Illusions Modulus comes to mind. Later models used two 6SN7 tubes in both the phono and line stage sections. 

I once owned one. Sold it due to building a digital based system. A superior phonostage would be quite expensive. 
Point is that need of a separate phonostage is dependent the goal in the design of the preamp.