Ekos problems

Freddy · Post by **Freddy** » 2013-02-05 23:38

I have some kind of earth/ground cable problems. I first noticed it after a upgrade including Keel, top plate (Linn original), and Woodsong plinth. Every time I touch the arm I can hear a an increased noise level (buzz). I have good connection between the top plate and ground cable. The connection between the arm (screws on the cartridge) and the ground is less good (20 ohms). Any suggestions what to do?

donuk · Post by **donuk** » 2013-02-10 10:10

Freddy
I notice you are not getting any replies to this.
It may be because it is difficult for anyone to really know what is wrong without actually looking underneath the bonnet. I would suspect that the solution is quite straightforward and cheap. But it does need an expert to have a look.
Earth hum can be caused not just by something not being properly connected to earth, but by something being connected twice, which may cause what is known as a earth loop.

It needs an expert.
Good luck
don, overcast downtown York.

ThomasOK · Post by **ThomasOK** » 2013-02-10 21:37

For some reason this didn't come up on my screen as being unread so I didn't see it until now. Ground problems can be very vexing at times. I have a customer who once had a ground problem like you describe that took three trips in before I could sort it out (luckily he lived close by). The first time we couldn't reproduce the problem in the store. The second time I disconnected the arm cable from the arm, plugged it back in and locked it in place and it went away. But a couple of weeks later it came back. I was able to get it to go away and come back by wiggling the connector - it was the black metal SME type. So I opened up the connector and found that Linn had soldered one of the connections with an unusually big blob of solder on it. Twisting the cable slightly would cause that solder blob to contact the metal case and short to ground causing the hum, twist it the other way and no contact and no hum. I resoldered the connection and it has been working fine ever since (a couple of years). So the fix was simple but tracking down the problem was not.

It is possible you have the same or a similar problem - possibly a break in one of the ground wires - but the best bet would be to have an LP12 technician take a look at it. You could try to isolate the problem by unplugging the arm cable and testing continuity of it and of the internal arm wires if you are comfortable under the LP12, otherwise I'd see a pro.

Freddy · Post by **Freddy** » 2013-02-11 23:52

Thanks for the reply! I have now taken arm off. It is obviously no connection between the arm and the earth cable connector at the arm base. I live pretty far from my Linn dealer so cant just go there and ask him to check it. He suggest that I send it Linn to get it checked and that is what I´m going to do now. He also suggested that it might be bad bearings. How is the earth connection done inside the arm? Is it really going through the bearings? It sounds expensive to repair!

Post by **lejonklou** » 2013-02-12 00:19

Freddy, before you send the arm away (only rarely to blame in my experience), how is the electrical continuity of the arm cable? You should measure that all five pins at the DIN end reach their respective phono/ground tag ends, without shorting eachother. The ground tag should also reach the subchassis (bearing and spindle), and continue to the top plate, when it's fitted to an LP12.

I have several times sourced ground faults to the inside of the DIN plug, both open circuits (for example the ground wire coming loose from its pin) and short circuits (as Thomas described above).