I have an odd noise coming from the right channel when on MC setting.Its a light thump,thump,thump then it goes away for about 4 or 5 seconds then comes back, then goes away etc etc.
I wondered if it was the amp as im running it through one of the aux/video channels, but i tried it on 2 other amps and it does the same thing, so it is the LXS or in fact the turntable thats causing it.
i am using an audio technica AT LP-120XUSB turntable with a denon DL-103r MC cartridge.
anyone have any idea what it could be as its only on one channel.??
many thanks, paul
I wondered if it was the amp as im running it through one of the aux/video channels, but i tried it on 2 other amps and it does the same thing, so it is the LXS or in fact the turntable thats causing it.
i am using an audio technica AT LP-120XUSB turntable with a denon DL-103r MC cartridge.
anyone have any idea what it could be as its only on one channel.??
many thanks, paul
Sounds like LF mechanical noise transmitted by the arm/cartridge and as you have proved its not the amplification I would check your arm and cartridge possibly cartridge suspension collapse?
Have you tried a MM cartridge ?
Have you tried a MM cartridge ?
i also took it off the MF unit and plugged it into the MC input direct of a NAD 3130 and the thumping went away
Do you the think there would be a fault with the MF unit? its less than a year old.
Do you the think there would be a fault with the MF unit? its less than a year old.
If your turntable works okay in the NAD you would think that but you also said -" it does the same thing on two other amplifiers " -post #1.
I notice you said you plugged it in "direct " to the NAD and its okay so whatever you used indirectly could be causing the fault .
In that case we are talking about LF oscillation/instability in your "indirect " equipment.
I notice you said you plugged it in "direct " to the NAD and its okay so whatever you used indirectly could be causing the fault .
In that case we are talking about LF oscillation/instability in your "indirect " equipment.
sorry i meant it does the same thing on both amps using the seperate pre amp, but when i plugged the tuntable directly into the 3130 pre amp MC it didnt make the noise
so the seperate pre -amp is prob at fault then-return?
so the seperate pre -amp is prob at fault then-return?
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cheers..what do you think could be wrong with it,just as a future reference realy
if it was older than a year i would look at testing it, so where would you start if you were going to test it?
if it was older than a year i would look at testing it, so where would you start if you were going to test it?
It must be certainly your preamp. Send it back if it is new
Sounds like a bias current is charging the input
can also be motor-boating or rf oscillations.
Sounds like a bias current is charging the input
can also be motor-boating or rf oscillations.
Long time since I heard the word "motor-boating " used by old guys like me in the communications field , that word dates back to around the 20,s/early 30,s.
You are right, very common with tubes and transformer coupling
A very low frequency oscillation caused by power supply and bad layout where some DC level feeds positively back.