Like Minds,
The Baby Blue was an interesting experiment that SWR tried, but for my money it was flawed from the beginning, and I owned one. If you go back and read the users manual, here are the folks who were involved in the prototype "We would like to sincerely thank all the musicians and engineers that helped us with this project and especially Walter Becker, Neil Stubenhaus, Phil Chen, Keith Jones, Jimmy Haslip, Michael Rhodes, Phil Lesh, Dan Schwartz, Dann Glenn and Dwayne "Smitty" Smith." Now unless I missed something, they didn't have an upright player involved in the design phase of that amplifier.
For my money that's why they were unsucessful. Ron Carter commented in bass player that his son had one and although it sounded good with EB it didn't cut it with DB.