First, being open, I am retired, so not manufacturing anymore.
Secondly, I had to change one part in the 11A line preamplifier, so had some listening testing to perform. I continue to test, although not every day. There is no reason why tube preamplifiers have to be artificially flavored.
I have been doing some designing on a "new" test speaker for a few years now. I was never able to find what I really liked. It has allowed me to set the xover so the speaker sounds lean, for component design and listening testing purposes. Being lean sounding, masking is minimized, so I am able to spot differences the preamplifier may create more readily.
After playing many many musical selections, I found my 11A to be slightly off on one selection. A slight touch up, and all is well again. After this, I adjusted the amplifier and xover/speakers for most accurate/natural sonics. This is extremely touchy, altering the zobel resistor by 0,00145% is perceivable. Obviously, variable controls are necessary for parts (and room) variations.
I have not be able to find SS preamplifiers (or amps) to be this accurate. SS tends to falsely boost the bass as well as other problems.
Added: When combining two different philosophies with flaws, the result is always compromises, the voices, the music just are not natural. I would rather eliminate weaknesses in each component first. The voices, dynamics, soundstage, music are more natural. I realize not everyone can design their own system, making it a "vertical" system. But it is something to strive for imo.
I, personally, will stick with tubes all the way for allowing music to be more naturally reproduced.
Cheers
Steve