The standard electronics on these basses (Streamer Pro-M and Fortress Masterman are identical). Both having no push/pull pot on the volume. If it does, it will be an aftermarket preamp installed.
The push/pull pot option appears on other Warwick models like the Corvette and Thumb![]()
How wrong I was. After thinking the preamps were both the same and told they were both the same, I found both are different. The Streamer Pro-M "DOES" have a push/pull volume. I stand corrected after adding a Streamer Pro-M to my stable and seeing it with my own eyes. Both awesome basses though regardless

Makes me wonder if they were short on the original preamps at the time and just installed what they had on hand.
That is what makes the split-J so versatile! I bet it still sounds great though!