Expected a photo of the tupperware, wasn't disappointed! A really good read, as someone who's owned a LB B4X but never heard about this modding business. Thanks!

Great review! I'm assuming the silicone o-rings are there to damp any tube ringing? I ended up modding with the V5i-D instead of the V6 Vivid, but see similar improvements. Sorry you had to lose your window in the process!

What sort of difference in battery life do you see now that the V6 Vivid are installed?

@miserybeforethemusic thanks for your condolences I used to use V5i opamps with B4X as well (while I still had feelings for that window). They provide a noticeable improvement in sound quality but do not push B4X to its max potential. For a difference of less than $70 between a pair, I think it's a much better option to go with a set of V6 Vivid. They turn the Little Bear into a grizzly.

O-rings help to minimize ringing noise when moving/touching the amp and when plugging headphones in/out. Some other members managed to stick two o-rings on each tube for even better support.

I get between 2-3hrs on my unit with V6 Vivids, depending on sensitivity and impedance of the headphones I'm using with B4X.

Nice review, I'm really like to read review of few cheap china portable tube amplifiers like super cheap AD3.
Also V6 make it not as portable in that case need to sandwich case for moving .

@Setmagic , thanks. Pocketable, no; portable, yes. Easily attaching a DAP to the enclosed side and carrying around in one hand, like a massive sandwich AD3 is on my wishlist.