Originally Posted by Fat Steve
I have a DB, and I also have a PBass with flatwounds. Same thing really. Obviously one sounds like a PBass and the other sounds like a DB but the strings feel the same. GHS Flatwounds:$20-25. D'Addario Helicores: $150
Most URB strings will have a gut/rope core (or in the case of Thomastik Spirocores, a stranded metal core of three wires with a cloth-like wrap around that) that will probably be a round core, and then subsequent wraps. They will have smaller wraps, by and large and can be a larger finished gauge; when I mic'd my Spiros at work, they went .044, .068, .85, .115, .148.
Similar? Sure, in that they are both strings that are made from winding wire over a core. The same thing? No. URB strings require different, larger machines and are more costly to make, hence that price difference.
To the OP, I don't see how you could fit a set of URB strings on an electric. The ball ends are much larger and the ball-end silk would easily sit over the bridge pickup. Even if you got that to work and cut them to size, as soon as you got past the A string, you wouldn't be able to fit the strings in the tuning peg; the Gotoh style tuners have a max opening of .085, with Fender tuners going to about .115. AFAIK
, there is a set of NS Design strings made for the Omni Bass (their 34" scale EUB) that they say will work on an electric bass, and are a rope/stranded core. That would probably be your best option in terms of finding something like that.