This is my first post but I felt compelled to share briefly my experience with this piece. I had some initial difficulty getting it right, but when I did the sound was great.
First off, the power supply seemed whimpy (it actually looked like the wrong supply) that came with it an was sensitive to noise. When I replaced it with a radio shack 15v 1a power supply, the unit sounded much better, and some noise I had was gone.
I also did a fair amount of tube rolling, and found that the stock tube wasn't giving me the sound I wanted. I found that a Tung-Sol 12ax7, or even a 5751 was better suited to the AT440mla. However, I have always found the AT a bit bright, and dumbing it down with "softer" tubes helped, but the lowered dynamics dulled it too much.
I found that overall, the Sovtek 12ax7lps was the overall winner on the AT, but even better on the Shure M97xE. Without being able to fine tune VTA etc on a Technics SL-1800, the Shure is less fussy and sounds better (to me).
There is nothing at all about this little pre that sounds thin or harsh, especially with the added supply, tube and right cart on this table.