No one’s going to jump down your throat.
This is a friendly thread used by nice folks.

Just head over to the Sony Walkman threads and say you listened to another manufacturers product?
Or even worse own one.
Regarding your 325X I haven’t heard them.
As others have said run them and keep running them in.
If you have any type of device even a small radio would do.
Just play music though them and you can even cover them up with a blanket so the tiss tiss doesn’t get annoying.
Pad wise they make a difference as you have found out.
You could cut a small hole in the S pad.
That’s called a quarter mod.
You can try Sennheiser HD414 pads.
These are far cheaper than stock Grado pads.
Bright yellow so might put you off?
If you find the G pads fine but the treble still a bit much you can try the tape mod.
This is just 1 inch tape around the outer side of the pad to make them a bit firmer so taking the driver a bit further away from your ear.
Another thing to try is the kitchen ply mod.
This is just kitchen roll.
This usually comes in 3 ply thickness.
Just cut the driver shape out and use 1 ply sheet and see how you go?
Place the 1 ply sheet over the driver and put the pads back on.
Finally you say your happy with the dac/amp as it’s works well with your other headphones and it should as it’s a good unit and some fine headphones so it’s just a problem with the Grados.
I like you am getting less tolerant of hyper treble now.
Not every day but sometimes just want more of a chill type of sound.
When I do I just use a ddhifi dongle type dac/amp.
Nice slightly rolled off top end.
I think of it as a bit like a micro valve amp.
It runs Grados perfectly even though it’s not very powerful.
Pictures of the kitchen roll mod and the micro valve amp

Have fun.