Tube amps known to have a low damping factor?

Compared to ss amps most tube amps have lower damping factors. Wolcott tube amps appear to be capable of a rather high damping factor for a tube amplifier.
Some amps with a high damping factor have little or no global feedback.

The Wolcott's are capable of a df higher than 20, much higher.

And a low DF might very well make another's speaker sound flatulent?:-)