UPGRADING A REGA ARM
I have had my Origin Live badged Rega RB 251 for around 7 years. It has served on quite a few turntables over the years and has been generally unloved.
As standard, these arms have in my opinion a grey squashed sound that is boring and coloured.
There are a million ways to update these arms, this is my take on the polishing of the proverbial turd.
Ok so it isnt a turd, the basic engineering of the arm is perfectly acceptable but there are several compromises.
Firstly, the arm tube is a complete alloy casting which is good, stiff and strong. there are no joints. which probably makes some kind of difference. The problem is, it rings like a bell. there are a couple of peaks and modes in the arm which basically means that the casting sings along with certain frequencies.
there are a lot of different ways to deal with this, people have filled the tube with expanding foam, drilled it out, someone even coated it with nextel paint which has a rubbery texture. meridian used it on the first meridian MCD (remember them?)
I chose to drill the casting to break up the modes. Taking some inspiration from Audiomods and Mitchell I came up with my own solution which works surprisingly well.
I decided to start by drilling into the underside of the casting rather than the top. the reasoning being that if i got the holes misaligned and it looked a bugger i wouldnt see it.
I marked the arm tube up after removing all the paint at 10mm intervals and centre popped each mark. Taped it to a bit of wood with a hole in so that the arm lift dropped into it and the tube laid square to its top face. Then pilot drilled with a 0.75mm bit in my pillar drill
As standard, these arms have in my opinion a grey squashed sound that is boring and coloured.
There are a million ways to update these arms, this is my take on the polishing of the proverbial turd.
Ok so it isnt a turd, the basic engineering of the arm is perfectly acceptable but there are several compromises.
Firstly, the arm tube is a complete alloy casting which is good, stiff and strong. there are no joints. which probably makes some kind of difference. The problem is, it rings like a bell. there are a couple of peaks and modes in the arm which basically means that the casting sings along with certain frequencies.
there are a lot of different ways to deal with this, people have filled the tube with expanding foam, drilled it out, someone even coated it with nextel paint which has a rubbery texture. meridian used it on the first meridian MCD (remember them?)
I chose to drill the casting to break up the modes. Taking some inspiration from Audiomods and Mitchell I came up with my own solution which works surprisingly well.
I decided to start by drilling into the underside of the casting rather than the top. the reasoning being that if i got the holes misaligned and it looked a bugger i wouldnt see it.
I marked the arm tube up after removing all the paint at 10mm intervals and centre popped each mark. Taped it to a bit of wood with a hole in so that the arm lift dropped into it and the tube laid square to its top face. Then pilot drilled with a 0.75mm bit in my pillar drill
Then drilled again with a 1.5mm bit
Then alternately with a 2.5mm bit
And alternately again with a 3.5 mm bit
I then couldn't be arsed to polish the bare aluminium, so i painted it silver. I read somewhere on the web that the paint added abit of damping to the tube, so I used this to justify my idleness and unwillingness to spend an hour with the autosol..............
Doing the 'flick' test with the tube hung up revealed a much more 'dead' sound. it now doesn't ring like a bell, and the sound it does make decays away very quickly.
When rewiring the arm tube i also tapped a thread into the last large hole to take a 4mm short bolt and ring terminal for the arm tube earth as I wasn't happy with the spring steel pin that fits into the counterweight stub thread
I rewired the arm with solid silver wiring and used cardas cartridge tags. Being a chepskate yorkshireman and not wanting to pay through the nose for a 'proper' tonearm DIN plug and socket, I wired it to a DIN socket that i made fit in the end of the arm pillar. This is a standard chassis mount 5 pin DIN socket. I had to sleeve it up slightly with black nasty to make it a resistance fit into the base of the arm pillar, cut off some of the mounting flange and add 2 o rings to space it from the base of the pillar. This is to make sure that it clears the nut at the top of the pillar that retains the lateral bearing. It is retained with the original grub screw
When rewiring the arm tube i also tapped a thread into the last large hole to take a 4mm short bolt and ring terminal for the arm tube earth as I wasn't happy with the spring steel pin that fits into the counterweight stub thread
I rewired the arm with solid silver wiring and used cardas cartridge tags. Being a chepskate yorkshireman and not wanting to pay through the nose for a 'proper' tonearm DIN plug and socket, I wired it to a DIN socket that i made fit in the end of the arm pillar. This is a standard chassis mount 5 pin DIN socket. I had to sleeve it up slightly with black nasty to make it a resistance fit into the base of the arm pillar, cut off some of the mounting flange and add 2 o rings to space it from the base of the pillar. This is to make sure that it clears the nut at the top of the pillar that retains the lateral bearing. It is retained with the original grub screw
I made a replacement arm cable from a set of spare phono leads with an earth cable added. the earth cable is retained with 3 bits of heatshrink at the din plug, the middle and near the end to stop it being pulled and damaging the din plug.
Before reassembly I cleaned up the bearings and their pins and inserted some foam into the tube. This is special audiophile foam that is most definitely not cut from an unused bath sponge ;-) to further damp the tube.
I also bashed a piece of aluminium rod into the counterweight stub to stop resonances in that too.
Before reassembly I cleaned up the bearings and their pins and inserted some foam into the tube. This is special audiophile foam that is most definitely not cut from an unused bath sponge ;-) to further damp the tube.
I also bashed a piece of aluminium rod into the counterweight stub to stop resonances in that too.
Once rebuilt, the grey squashed boring sound was gone. No peaky response, just a lovely evenhanded neutral sound with plenty of the HiFi mag favourite air and space. With much better imaging and instrument separation. I think that the silver wiring gives it the naturalness, the arm tube mods give the neutrality air and space, the separate earth the better instrument separation. Adding a dedicated earth wire did the same to the standard arm.
All these mods are attainable by anyone who can count the number of fingers they have, there is no black art to it as some would have you believe. It is simple engineering, not rocket science. And it could be done to any Rega RB series arm.
Hopefully someone may find this page useful, if you do, don't be scared to approach the arm mods yourself. New parts are available from Rega for not much money.
The main bit that can be fiddly that you really need to get right is the alignment of the arm tube in the yoke when you reassemble. what I did was to measure the inside gap between the 2 upright parts of the yoke with digital calipers, the outside of the arm tube bearing housing, minus this from the yoke value, divide this figure by 2 and you then have the gaps you need to retain between the yoke and the arm tube bearing housing on either side. I used an old set of feeler gauges that i separated and then stacked to make the required thickness to measure the gap and align it properly when resetting the bearing pins. given the manufacturing tolerances its better to do this rather than rely on someones measurements. I found the yoke casting pretty rough on mine and there is nothing to say that another arm will have the exact same measurements.
give it a go, although I accept no responsibility if you hack into yours and make a dogs dinner of it. :-)
All these mods are attainable by anyone who can count the number of fingers they have, there is no black art to it as some would have you believe. It is simple engineering, not rocket science. And it could be done to any Rega RB series arm.
Hopefully someone may find this page useful, if you do, don't be scared to approach the arm mods yourself. New parts are available from Rega for not much money.
The main bit that can be fiddly that you really need to get right is the alignment of the arm tube in the yoke when you reassemble. what I did was to measure the inside gap between the 2 upright parts of the yoke with digital calipers, the outside of the arm tube bearing housing, minus this from the yoke value, divide this figure by 2 and you then have the gaps you need to retain between the yoke and the arm tube bearing housing on either side. I used an old set of feeler gauges that i separated and then stacked to make the required thickness to measure the gap and align it properly when resetting the bearing pins. given the manufacturing tolerances its better to do this rather than rely on someones measurements. I found the yoke casting pretty rough on mine and there is nothing to say that another arm will have the exact same measurements.
give it a go, although I accept no responsibility if you hack into yours and make a dogs dinner of it. :-)