i'm looking for strings to buy for my new 33 1/4 scale (i believe rickenbacker scale) bass. i play power metal and want to use 50 strings because 45 seem a bit floppy. i;m thinking rotosounds because of the good mid presence. should i get 50-70-90-110 or 50-7-85-110?
The 90 A string will feel closer to the rest of the set. A set that heavy but with an 85 A is pretty oddball if you asked me, Rotosound probably had an artist who liked it like that for some reason so they made a set out of it and never looked back.
Why not make your own custom set? http://www.bassstringsonline.com/Build-your-own-string-set_c_163.html
105-45 will work if you like you strings slinky ... otherwise you might try 110-50 And yes 33 1/4" is the length.
What is the distance from the Ball End to the E-String tuning post? This is what will determine the overall length of the string you can use... Even though an instrument is XX scale length, does not mean you can use XX scale length strings or if you are limited to XX scale length strings...
If I may expand on what Jason said: Most long scale strings are designed for Fender-style top load bridges and 34-inch scale length, as that is the most copied and common. As Ric-5 stated, Rickenbackers do have a 33 1/4 inch scale length, but the bridge has an after length that is longer than a Fender top load bridge, so the same strings work on Rickenbacker 4000/1/2/3 basses. But there are others out there: if you have a short top load bridge, the string will be too long and bind the main speaking length of the string around the tuner post, risking fatigue and breakage. If you have, say, thru-body stringing, or a different headstock and tuner setup, they may be too long or too short. That is why Jason needs to know the distance from the ball anchor point to the E-string tuning post. Now, that said, and it sounds like you have a Rickenbacker copy, because nobody else makes 33 1/4 inch basses that I know of, standard long scale will probably work. Then, take either the D'Addario or CircleK tension chart, find out what the tensions at regular pitch are for your favorite style and diameter of string (it doesn't matter if it is a different brand - they are all made about the same way, and so the comparison is what matters, not the actual tension to the fraction of a pound), and then cross reference the charts to find which diameter of string has the same or similar tension for the drop pitch. Then using that as a starting point, if you like that tension, then that is the new diameter or gauge of string to purchase. And if you want it tighter, you can go up a diameter or gauge, and if you want it looser, you can go to a thinner diameter or gauge. Then contact Jason to discuss the matter and get his recommendation.
This is what you want for D standard tuning. I used them for years and they're great. http://www.juststrings.com/lab-m70.html
Couldn't find that exact set on Jason's site, thus the link from Just Strings. But I agree, order from Jason if you can.