"I've already traded emails with Chris J. at Parts Connexion, and he expressed willingness to have me send in the Job for evaluation of a further upgrade path. I'm seriously considering doing so, as I don't possess the expertise to tackle such an undertaking myself, and have enough respect for the Job's basic design that I'm disinclined to just "throw darts" to see what sticks. It'd be helpful to me to hear from any other Job owners/fans who have considered these sorts of upgrade and may have arrived at some solid conclusions."
I was thinking about having the speaker terminals replaced until I read the 6 Moons review of the new JOB preamp and the interview with the designer who stated that the stock terminals sounded better than other more expensive ones, so I left well enough alone!
Your best bet to improve the sound would be to go with the Sweetcord or some other high end power cord and an upgraded fuse. Other than that, I would not mess around. It is a great sounding amp! if you are still hankering to improve the sound, wait until later this year and spring for the new mono blocks. You will likely spend less on them than spending your hard earned money on some of the after market upgrades. My 2 cents.