It may sound funny, the headline of this post.
I love the sound of tubes, have owned tons of tube equipment and yet - I have never designed a tube piece ever. And add to that mystery the fact that when I design a piece of equipment I design for myself. I don't ever design something just because the sales team or marketing wants it - I design something I want to own so I can fall in love with it. I put my heart and soul into every design every time and for better worse, the results make a certain number of people happy. So all that being true, if I love the sound of tubes, then what's up?
In a nutshell I have always believed that everything we design must be a sensible long term proposition: one that has no obvious flaws and achieves the musicality we are looking for. Tubes simply have too many obvious flaws that cripple every design that uses them. From heat, fragility, lack of longevity, change in sound over time, microphonics, vibration sensitivity, high output impedance, trouble driving speakers and cables and the list goes on. Is there a similar list for solid state? You bet and it's as long as your arm - but I find the flaws of solid state far more manageable than those of tubes.
Life and audio designs have always been and will always be a series of calculated compromises. What I hope I've been able to point out in this series of posts is that as designers we have choices and those choices aren't limiting our ability to produce wonderfully musical products that delight our customers. The choices we make shouldn't ever restrict any serious audio designer from building products we can each fall in live with, be they tube or transistor or a combination of both.