Help! I've got a hum in my new AT 440 MLa

[Brett A]

Help! :cryin:
I received my new Audio Technica AT440MLa in the mail yesterday. I spent the evening mounting and adjusting. Sounds wonderful! I got excited and started to re-organize my vinyl collection this morning.

So there I was, on the floor pawing through my collection with tone-arm lifted above the end of a spinning record (too involved in my sorting efforts to change the record), when after a few minutes, it dawned on me. The system is humming!

I traced the hum it to the cartridge its self. How did I do this you ask?

There is no hum if:

I remove the headshell/cart. from the S-arm entirely.
I swap it with a different headshell/cart.

There continues to be a hum when

I swap out the little leads b/t cart and headshell
I mount the 440 on a different headshell
I remove the stylus from the cart body

The hum gets louder when

I turn the TT motor on. (It a direst drive Pioneer, photos here (http://i272.photobucket.com/albums/jj161/mynewt/TT1.jpg?t=1205679321) and here (http://i272.photobucket.com/albums/jj161/mynewt/TTandShanB-W.jpg?t=1205679353))
I swing the tonearm closer the my amp.

:mad2:
I searched the archives and seems that hum is something that happens. What am I to do? Did I get a defective cartridge?
Any thought would be appreciated.
Thanks, Brett

:thumbsup:

[canuckle]

It hums worse when it's closer to the amp? You know that you can't have an amp anywhere where its magnetic field will reach a turntable, right? If it does, you'll hear a hum ;)

90% of hum issues are really grounding issues. Is your turntable properly grounded?

[JohnMichael]

Are things any better now Brett? I am sorry I missed this when originally posted. My first thought is AT's are so well shielded that you might have a defective cartridge. I have also had hum problems when the clips that attach to the cartridge pins or headshell pins are bent slightly and so are too close to another clip. Oddly enough with some table/cartridge combination the hum will stop if the ground wire is not attached. I would check it both ways. Also if you are using a seperate phono pre-amp it's position can lead to hum and will need to be moved until you find a hum free home for it.

[Brett A]

Are things any better now Brett? I am sorry I missed this when originally posted. My first thought is AT's are so well shielded that you might have a defective cartridge. I have also had hum problems when the clips that attach to the cartridge pins or headshell pins are bent slightly and so are too close to another clip. Oddly enough with some table/cartridge combination the hum will stop if the ground wire is not attached. I would check it both ways. Also if you are using a seperate phono pre-amp it's position can lead to hum and will need to be moved until you find a hum free home for it.

I tried swapping out the lead wires, tried moving them to different relationships w/each other, swapped head shells, cartridges, etc. I did everything to determine that it was indeed this particular cartridge that was humming.

So I sent it back and ordered another from a different supplier, one that deals only in TT supplies.

By reading posts over on Audio Karma and Audio Asylum, it seems likely that a defective run of these may have left the factory. Bad internal grounding.

I'm one of six people who reported this problem in a four week period in a thread over on AK. One person on AA solved his issue by reliving the pressure the corner of the mounting nut was placing on the cartridge body by turning one of its flat sides parallel to the cart wall.

For the few days I had it, even with the hum, I was really excited to hear my records without all the terrible grain and cymbalence (sp?). Hopefully all will be well by next week when the other one arrives.

[Brett A]

It hums worse when it's closer to the amp? You know that you can't have an amp anywhere where its magnetic field will reach a turntable, right? If it does, you'll hear a hum ;)

90% of hum issues are really grounding issues. Is your turntable properly grounded?
I made efforts to determine that it is indeed this cartridge. (see esp. the second bullet point in my original post)

As to the proximity issue, I moved the TT as far away from the amp as I could (~4.5 ft) and it still hummed. My other cartridge never did hum in this config.

[JohnMichael]

By reading posts over on Audio Karma and Audio Asylum, it seems likely that a defective run of these may have left the factory. Bad internal grounding.


For the few days I had it, even with the hum, I was really excited to hear my records without all the terrible grain and cymbalence (sp?). Hopefully all will be well by next week when the other one arrives.



I am glad you like it. I thought that stylus used in the cartridge would solve the problems you were having. Excessive syballence can be annoying and is a sign of mistracking or a poorly aligned cartridge.

[Brett A]

I am glad you like it. I thought that stylus used in the cartridge would solve the problems you were having. Excessive syballence can be annoying and is a sign of mistracking or a poorly aligned cartridge.

:yesnod:

I got the new 440 MLA today. Amazing because I ordered it around 4:00pm on Thursday. It got here to Massachusetts from Oregon in 36 hours w/free shipping!

There's no hum, it's dead silent. Sounds beautiful. Thanks John for this recommendation.

I'd also like to put in a good word about www.turntableneedles.com They sold me a non-humming MLA for about as cheap as you can find them now-a-days. Also, very friendly and helpful via email.

:thumbsup:

[JohnMichael]

:yesnod:



I'd also like to put in a good word about www.turntableneedles.com They sold me a non-humming MLA for about as cheap as you can find them now-a-days. Also, very friendly and helpful via email.

:thumbsup:



Thanks for the tip on a good source to buy the cartridge.