Thanks for the tip Roger, I had already read that page and thought about it. I wanted to listen to it stock first. Not replacing any op-amps or anything just replacing faulty components with the same values but of better quality. I am perfectly happy with the result and the sound. I am sure there are tons of possible DIY upgrades but I think I will keep components as stock as possible. At least as long as I am using the Quad 34 as the preamp. Visuals in another thing. This pair was quite chipped and in slightly different colors. I took the opportunity to repaint them in a custom color. I also replaced all visable LEDs, the green ones on the 34 and the power indicator on the 405-2 became orange. Suits the two tone color theme, BMW Marrakech Brown and the same flat Champagne color as the anodized heat sink on my 405-2 (I don't know if it is the original color or if it turned that way by age but it was a pain to color match).
