I replaced the volume pot on my tube preamplifier.

@jordi  Obviously, I concur. Contrary to the seeming naivete of my opening post, I have run into this issue before. I built an overkill phono preamplifier back in the day and it sounded fantastic (with a cheap RS sourced pot). I was to demo it to a dealer and wanting to make the best impression, replaced the pot with a Sfernice unit ordered from France. I hastily swapped out the pot, tested on the scope and packed up the amp. The demo went well with the dealer saying, "don’t call us, we’ll call you." Let’s just say, the fancy pot destroyed the sound. And that is why I’ve waited all these years to try a different pot.

@rowd  Thanks. I use mono pots too.

Maybe we need to pressure manufacturers to use better pots.

@rowd Good to hear. Is it this one?
Tokyo Ko-on Denpa P65C Series Variable Potentiometer
Where did you buy it?
 

@asvjerry  Huh?

@noromance ...(Surely you jest?  ;)  Always wanted to ask that and "NONE?!" *LOL*

@bruce19  Kindly follow up when you make the modification. The Black Beauty RK40 is not in production but there seems to be some online.

@asvjerry  You must be wiped.

...I like pot in volume, too...

@viridian  No. Log to log.

@erik_squires  Like these?
DACT audio attenuators
DACT Shop
CT2 Stepped Audio Attenuators - DACT

Interesting that these probably would fit but I’m not sure how well SMD resistors sound, and I wasn’t gonna take a $300 tryout! If I was building my own phono amp (some day!), I’d use a switched unit with bulk foils.

@erik_squires  No. There’s not enough room to fit a discrete unit. The TACOS are carbon wipers whereas the Alps were plastic film. And, truth be told, I’m somewhat frugle in wringing out the best bang for the buck. 

Thanks @viridian. I've played a bunch of tracks to get a measure on the changes. Everything is louder–much more dynamic, music soars–it's almost unsettling, deeper bass, sweeter highs, more air, hidden instruments and voices revealed. 

@mulveling  It's certainly an eye-opener for sure. Most manufacturers are component lazy, compromising their product sonically and economically.