Greetings! Here is a demo I made for my Aria Pro II SB JR-600. The JR, which stood for "junior", was a short-lived series from the early 1990s. This particular bass appears to be from 1990 and is finished in "pearl black". Pearl black has a more sparkle effect to it, versus the regular black finishes resulting in almost a "gun metal gray" finish in certain lighting. Also, while the neck plate says "Japan", I'm not convinced the bass was made in Japan, based on the history of Korean made instruments from this era.
In my opinion Aria had a great idea to make a cheaper version of the SB basses, and while this is a very nice bass, it probably could have been better. First, to keep more of the SB character, I think it would have been better had they made it with an SB style pickup. That said, P/J pickups do give a nice variety of tones. Second, I wish the neck had been of three piece construction versus the scarf joint construction (another clue that it might be Korean made). In my experience the scarf joint construction Arias of this period were vulnerable to warpage creating some real headaches to get them playable. Overall, these basses are worth a try, especially if you can find them at a bargain price (say $200 or so). Of course, instruments in pristine condition with no issues can expect to go for a higher price.
The specs can be found here from this 1991 Aria catalog. One thing that is different from the specs is the Badass II bridge that I had installed as an upgrade. I used Dunlop "Trujillo" steel, roundwound strings for the demo. The details of the recording can be found on the video but basically I recorded a clean track of riffs with the various pickup settings, and then some riffs from "Enter Sandman", "Paranoid", and "For Whom the Bell Tolls" to show the versatility when used with a Dunlop MXR-80 DI pedal.
More pictures of the SB JR-600 can be found here: http://s227.photobucket.com/albums/dd117/vintagejapanbass/Aria%20Pro%20II%20SB-JR600%20Black/