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Anyone Know Where I should Look to Figure Out This Hum?

http://https//www.dropbox.com/s/faxmop972rok7i1/Noise.m4a?dl=0

I recently purchased a Lamm LP2. First couple days, silent. Now this. It's coming from both sides equally, turning up the volume makes it louder. It's not the cartridge. Noise still there when I unplug the turntable inputs from the phono preamp. It sure doesn't sound like a ground hum and since it's both channels I don't think it's going to be a bad tube . I have another set of tubes on the way but they won't be here until next week so I can't double check that. I swapped out the rectifier tube and that changed nothing. 

Help!
dhcod
uberwaltz's avatar
uberwaltz
13,381 posts
 
But why the ground loop hum not happened in first couple days?
My initial thoughts were how would this be solved by a cheater plug but....

It is likely a very good indication that something has failed or is on the verge of failing internally in the Lamm and was just very unfortunate timing on the ops part.
Did you buy it used?
If it was myself and it had started acting up after just two days I would be talking to the seller......
dhcod OP
710 posts
 
I’m not worried. Seller is a friend.

My wife is saying that our fridge problems started around the same time. Maybe it’s related to the fridge some how? Who knows. Maybe when the fridge is fixed on Friday the hum will come back and I"ll have to take the cheater plug off. That would be funny.

All I know is this phono preamp sounds incredible! 
no_regrets
543 posts
 
So sorry to revive an older thread, but am curious about two things....

1.  Were you able to solve the hum/buzz problem?  Was it the fridge, the wiring from an older house, bad capacitor, etc.  Are you still using the cheater plug as the fix?

2.  I am considering getting a Lamm LP2.1 and am wondering if the LP2.1 is also incompatible with older home wiring as my house is over 76 years old now.

Thank you,
Don
dhcod OP
710 posts
 
Still using the cheater plug and have since heard from two Lamm owners that have had to float a ground for some reason and a few that haven't in old homes. It's all a mystery and yet it really doesn't matter. I would be hard pressed to imagine a better sounding phono preamp than the 2.1 that doesn't cost $25k. I will be making that upgrade from the LP2 at some point this year if all goes well. 
no_regrets
543 posts
 
@dhcod 

Thank you for your reply!  That's quite an endorsement for the Lamm.  I hope all goes well for you and you are able to make the upgrade to the LP2.1 :)

Wishing you all the very best of health and happiness!
Don
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