I too wondered whether to get the Evolution upgrade, (my preamp was already upgraded to K-1X status when I purchased it, by the way), and then just decided to "Go for it!" No regrets so far!
Whether it is worth to you (Regarding whether to get the Evolution upgrade) depends on what you are looking out of it.
If you are looking for a brand new sound: Sorry, it won't do it. It was already uncolored and transparent, and it remains so.
If you are looking for a slightly more quiet line stage:
Yeah, it is that. (Very Slightly, since it was already incredibly transparent.)
If you are looking for more gain out of your phono stage, without any additional noise: Once again, Yeah! (Only this time, the difference is not subtle!)
I fell into the later camp. I really like this preamp, as it just gets the heck out of the way and lets the music come on though! (Therefore, I decided to hang onto it and get the upgrade.)
I wanted a bit more gain out of the phone stage for two reasons:
One, I was having to adjust the volume control whenever I switched from my turnatable to my CDP. Since the Evolution upgrade adds 10 db to the phono stage gain, it now means that I don't have to fiddle with the volume control when switching from analog to digital. (The volume control for CDs was at about 10 or 11 O'clock position, and vinyl at about 1 or 2 O'clock position.) Now, they are both at the 10 or 11 O'clock position.
Two, at some point in the future (probably distant future), I am thinking of upgrading to a really low output MC cartridge. I currenetly use MC cartridges with 0.4 - 0.6 MV output (Koetsu Rosewood Signature and Shelter 90X).
But I think I might want to try out a platinum Koestu (0.2 mv) or an Allaerts (0.1 mv), pr other really low output cartridges. Now that I have upgraded the phono input, it will allow those cartridges to work just fine.
Feel free to contact me if you need additional information.
If I were you, I would get it done, since you will actually be getting multiple upgrades, and will only have to pay for the shipping once, rather than two ro three times. Good Luck in your decision!
