Time for a Pre change? Need the wisdom...

I bought a mac C 41preamp and a pair of AA 10T’s. 

There is a harsh edge riding on the high end... I cant get rid of it.  I have changed everything out and still cant remove it...... I have the opportunity to buy a Parasound A21 and a P6....  What’s the feeling here on this era of Mac? I have had people I respect and in the business prefer the Parasound over the Mac. 

Is the Mac on the bright side and is the P6 in the same ballpark. I have emailed AA about the harshness... maybe xover or maybe bad tweets? It’s killing me. I feel if I clean house (amp- pre) with new equipment I will have a better chance at getting to the relaxing listening days again.

All opinions are welcome... I have a thick skin as I know everything... lol
What makes you think it's your preamp and not your speakers or another component?
Have you experimented with a different pair of speakers for comparison?
Just cirious?
I've heard some complain about some Mc's being bright to harsh, but first, room acoustics and speaker placement.

If you have bare floors between the speakers try covering them up with pillows or rugs as an experiment.
Next, try crossing the tweets far behind your head, or far in front. Knowing what kind of speakers you own would help this.

If you are listening with your back to a wall, cover it with something as well.
Brightness can also be caused by higher ordered harmonics in very small amounts. This is why transistor equipment tends to sound brighter and harsher than tubes.

But Erik's suggestions above are good- if your room has too many reflections due to bare floors and the like, its going to be bright.