Hello and welcome to the forum!
I have a pair of RB-81 purchased new in 2008 that are marked Ref IV on the tags.
From looking at the product listings the major difference between the RB- 81 and 81II is the crossover frequency with no change to the outward appearance.
Hope this helps!
If you have a decent internal sound card on your laptop its easy from the headphone jack to any line level input on your pre/amp!
http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4776338&body=MAIN
They sure don't write them like the ole Johnny cash song.....
From the backdoor of your life you swept me out dear
In the bread line of your dreams I lost my place
At the table of your love I got the brush off
At the Indianapolis of your heart I lost the race
I've been washed down the sink of your conscience
In the theater of your love I lost my part
And now you say you've got me out of your conscience
I've been flushed from the bathroom of your heart
In the garbage disposal of you dreams I've been ground up dear
On the river of your plans I'm up the creek
Up the elevator of your future I've been shafted
On the calendar of your events I'm last week
I've been washed down the sink of your conscience
In the theater of your love I lost my part
And now you say you've got me out of your conscience
I've been flushed from the bathroom of your heart
If you would like to get rid of an extra tube tester that can test old 4 pin through "modern" tubes I would be happy to lighten your load for ,of course, cash and pick up!
I have wright 2A3s and klipschhorns also, I am running a vintage scoot 130 pre with them that has been rebuilt by NOSvalves. I like the phono stage and can't live without tone controls to change individual recordings. If the tonal shortcomings are generalized among most recordings people now compensate by using different interconnects to shape the sound since most new pres don't have tone controls. Room treatments are also an option. Good Luck!
I just got rid of one of these AV security trojans...
when you first see the screen that says a virus is detected or click to activate AV software DONT CLICK IT OR ANYWHERE NEAR IT DONT DECLINE SAY NO OR EXIT. Doing so allows the virus to take over your computer, hit alt+f4 to remove the pop up screen without allowing the virus access.(this according to a norton tech) the malware is present on many websites and I got it through a picture of a used truck on craigslist. Good luck!