Rewiring tonearm without hum?

[tmblack]

I have revired a Rega tonearm so wires go thru top instead of base which is prone to breakage.

The 4 wires from the cartridge go to the R and L phono sockets.
Now there is hum. Should some of these leads be grounded at ohono amp end and/or arm?

Tom

 

[AudioOrigami]

hi tom

there is normally a black wire goes to the earth on the arm and your preamp....is it still there?
what model of arm is it?

best wishes
j7

 

[tmblack]

Its the original one that came with the Rega 2 and is S shaped.
The cable felt out of the screw on mechanism and broke all the wires so now I have rewired it going out from the top. Grounding the tonearm to the Phono amp has an effect but it still hums.

Do people ground one of the wires from the cartridge so it becomes an unbalanced source?

Tom

 

[AudioOrigami]

hi

i suspect your next move shold be to remove the cartridge

and get a mutimeter -and check the conection from each terminal in the phono plugs ...back to the headshell...

it should be no leak to each of the other wires...so try 1 wire at headshell and note what readings you get at the 2 phono plugs and 2 phono screens

also check that the earth wire gives continuity to the arm tube

sometimes soldering to slow can melt the insulation back on the fine wires ..i guess you may have 2 touching

hope that helps...check my web site to see how i done a rega r200 arm ...may be simliar to yours

best wishes
j7

 

[tmblack]

Thanks for the tip.
Where does the black wire (ground) connect to the arm?

Tom

 

[jeff spall]

Hi,
Rega and Origin Live use a spring clip that is fitted into the thread that holds the counterwieght stub.

My favourite method is to drill a very small hole in the underside of the arm tube (0.9mm is ideal) and then use a little piece of 1mm copper wire from a bit of twin/earth mains cable. This should be a tight press fit into the hole. If you only have a 1mm drill, flatten the wire a bit so its tight.
Take your ground wire up the arm, out of another hole near by and solder it to the copper stub.

regards, jeff

 

[tmblack]

I like to do no drilling on the arm right now.
Where did the original black wire connect to the arm?
How does one remove the metal arm from the yoke pivots?
The 2 screws are impossible.

Tom

 

[AudioOrigami]

any chance of a picture of your arm 1st tom?

 

[tmblack]

Hi Audiogami,

its exactly the RB200 on your website.
If you can tell me how to take it apart for rewiring that should do it.

Thanks

Tom

 

[AudioOrigami]

hi
the earth wire come down inside the(thin black wire) arm base...and at at the 5 pin din conection plug it jions to the black earth wire to pre amp
also at the 5pin din there is a copper strap...the copper strap contacts round the side of the 5 pin to give double earth

so if u get a multi meter the outside of the arm should give a strong reading to the black phono earth wire

i suspect if you take the 5 pin din plug out ...and look @ the fine wires...1 of them will be touching the earth strap or broken

also notice on my web site how i made a simple anti skat for this arm

any problems ...strip the base and send or post the pictures for a better idea

hope that helps
j7

 

[tmblack]

I rewired it from the cartridge end thru the S shape and now its stuck at the counterweight end. How do I bring the wires down the narrow vertical column?

It seems I need to remove the S shaped tube but how can I do that?

Tom

 

[AudioOrigami]

the wires are prob stuck at the horizontal bearing entrance
just below the s shaped tube you mention...its near getting into dismantaling the bearings now

what thickness of wire are you rewireing with? maybe its to thick?
maybe your jiont onto new wire is to thick?

normally i isolate the earth internal wire ..and solder a new thin wire onto the 4 signal wires and pull thro...this gives me a safety net,before i pull thru new wire
.....its sounding like the bearings needed dismantaled to do this 1 job properly

you havent given me any photos ...so its hard for me to advise you to go much further...i cant advise you to dismantal the bearings....have another look see if u can see anything with a bright light

patience pays off big time

best wishes
j7

 

[tmblack]

Sorry I don't have a webcam here, but soldering a wire and pulling it thru just might work. Looks like each wire is about 28 gauge.

Tom