randytsuch's audio page

Rega RB-250 tonearm mods

Structural mod

That is what origin live calls their version of this change, but is really is just changing out the cheap plastic end stub with a metal one, and using a better counterweight.

I picked the Michell counterweight, as reviewed here
http://www.vinylengine.com/michell_tecnoweight.shtml

It was not cheap, but I liked it because it is easier to adjust the counterweight on it. It was a scale built in, versus the others where you just move it back and forth, and need a scale to set it.



Rewiring

I also rewired my arm. I got the arm cheap because it had an intermittent wire, so I just changed it out.
There are many pages out there that talk about rewiring regas, here are some links
http://www.hi-fi.com/diy/rega/
http://melhuish.org/audio/rewire.html
http://csown.dhs.org/hi-fi/rega_mod.html

And, here is what I did. Sorry, did not take pics while I was doing it.
I decided to use the Cardas tonearm wire from Percy for this job. Some people advocate the discovery wire, and solid silver wire, but I was worried about how this wire would effect tracking. Cardas is only 33 ga wire, and it is stranded to make it more flexible.

First, I removed the rubber stop from the bottom of the arm, and cut the wires at the little circuit card that is attached to the rubber. I cut the card off, and just saved the rubber stopper.

I tried to solder my old wire to the new wire, but when I tried to pull the new wire through with this method, it just broke the old wires, and broke the ground wire to boot. The tonearm ground wire went from the little circuit card to a little copper piece that is close to where the end stub screws into the arm. The copper is wedged into the arm to make ground contact there.

I ended up running a piece of 30 gauge solid wire through the arm. It is pretty easy if you remove the end stub, and start from the bottom.

I then soldered the new wires to the 30 gauge wire, and pulled them through. It worked, but it was a little too fat at the solder point, so it pulled out to little rubber gaskets, one a little before the wires enter the bearing area, and one where the wires enter the tonearm tube. The point of these gaskets is to make sure the wires don’t mess up the bearing movement, I think.

I was able to pull the new wires back and forth, to get the rubber gaskets back in place.
I used a piece of solid 30 gauge wire for the ground wire. I soldered it to the same copper piece the old ground went to.

I drilled a small hole in the rubber stop, and pulled the tonearm wires though the stop, as well as the ground wire.

I carefully soldered clips on to the wires at the headshell. I reused the rubber piece that was there, to run the wires through.

I then pulled them back, to leave just enough at that end. Then, I put the rubber stop in at the bottom of the arm, but stuffed a little wire in at the bottom, for a service loop.

For now, I taped the wires to the rubber stop, where they come out of it. This is temporary, and I will glue them in place, as soon as I am sure it is all working ok.

I put on Eichman bullet plugs on the other ends. For a phono plug, the low mass design of the RCA’s makes sense to me.

I did not shield at all, was a little worried, but no noise when I connected.
Also, tracks fine. I was worried about how it would track after I rewired, but played a few albums, and they had no problem at all.