ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I have spend a lot of time cleaning, lubricating and adjusting and the tone arm lowers and lifts very fine now.
I connected it to my Beocenter 9000 and was sad to hear that it didn't sound very good. There is a humming sound which gets worse when I touch the cabinet.
Can it be a ground problem?
/riis
First I suspected the DIN plug as it isn't the original one. I have opened it and it looked ok.
Other places to look for a bad ground connection?
Check that the shield of the DIN plug actually connects to the chassis ground of the amplifier.Run an external wire to diagnose.
Martin
Dillen: Check that the shield of the DIN plug actually connects to the chassis ground of the amplifier.Run an external wire to diagnose. Martin
Pardon my ignorance but how do I do that?
Run a lead from the metal chassis of the Beogram to the metal chassis of the amplfiier.The amplifier often has a small fingercrew near the phono socket, provided for this.
Dillen: Run a lead from the metal chassis of the Beogram to the metal chassis of the amplfiier.The amplifier often has a small fingercrew near the phono socket, provided for this. Martin
Thanks Martin. I shall try that.
I have found the finger screew on the amplifier. Where would be a good place to attach the lead on the Beogram?
Some Beograms have a fingerscrew too, but anywhere on the metal, really.Easiest would probably be to let the lead touch the tonearm housing while playing.
Dillen: Some Beograms have a fingerscrew too, but anywhere on the metal, really.Easiest would probably be to let the lead touch the tonearm housing while playing. Martin
It works fine with the lead attached as you descriped. No humming at all. So it must be the plug. Do you know what can be wrong with it? I have taken some pictures of the plug, but I can't upload them. Doesn't it work with a Mac computer?
The DIN plug is with a "gold" metal housing. Should I replace it with one of plastic?
I'm not very good at soldering
You could measure around a little and see, where the connection is lost.Is it from the Beogram metal chassis to the DIN plug screen? Or from the DIN plug screen to the amplifier chassis.You could also use the external lead for this; Fit it to the amplifier, touch the other end to the DIN plug screen, etc..
Dillen: You could measure around a little and see, where the connection is lost.Is it from the Beogram metal chassis to the DIN plug screen? Or from the DIN plug screen to the amplifier chassis.You could also use the external lead for this; Fit it to the amplifier, touch the other end to the DIN plug screen, etc.. Martin
I have tried to run a lead from the Beogram to the shield of the DIN plug. Same humming. That indicates that it is the plug that is faulty, doesn't it
I then ran a lead from the screw on the plug to the fingerscrew on the amplifier. Then there was no humming. I think I can either keep it that way or replace the plug.
My guess is, that the contact inside the amplifier socket, that receives the DIN metal shield has been bent in a way so it doesn'ttouch the shield when it's inserted.What type of amplifier are you using?
Dillen: My guess is, that the contact inside the amplifier socket, that receives the DIN metal shield has been bent in a way so it doesn'ttouch the shield when it's inserted.What type of amplifier are you using? Martin
I'm using a Beocenter 9000. I don't think the contact is faulty. I have a Beogram 4004 and another Beogram 4002 both with original DIN plugs and they work without problems.
Someone has put another plug on the Beogram that is humming. A "gold" metal one. The strange thing is that it looks ok. The soldering is fine and it doesn't look damaged in any way.
Replacing the plug would be fairly easy to try, I suppose.
Dillen: Replacing the plug would be fairly easy to try, I suppose. Martin
I have now replaced the DIN plug and the humming has gone! Right now Dire Straits - Communique is playing on the Beogram. Nice and clear sound.
Well done!
I suppose that was just one more case of a previous owner wanting to "upgrade" his system using shiny goldplated stuff..Restore to original and it works again...