Topping Pre90 Switching op amps?

I have found that the pre90, in my system, renders many recordings beautifully transparent and many other recordings thin and brittle. It seems that swapping op amps might be a solution. Has anyone done this? If so kindly report on your experience. 


@dbb Surprisingly, it did not not reduce the transparency. I can still hear all of the details. I am using Altec A7 speakers which are over 100db efficient and it added a slight bit to the noise floor but you need to put your ear up to the treble horn. Preamps I had before this were Pass Labs X1, Modwright LS 36.5, Black Ice Audio Fusion F360. All had a higher noise floor. I tried the Topping D70s direct which was excellent on it's own and lead me to the PRE90 which on it's own is dead silent. 



Does the pre90 remote work well on yours. Mine, as reported by others in reviews, works poorly. I wonder if this issue has been fixed in newer production models.

The remote is weak. Not great off axis. I use an infrared repeater and it works great!

Just a follow up of using the tube buffer with the PRE90. I changed the stock Tungsol tube to an Allen 12au7 and the noise floor is dead silent now with a nice balanced sound. So you can have your cake and eat it too! I have a Psvane Art series 12ua7-s on the way to compare. Let's see what it brings to the table?