turntable question

[ahardb0dy]

I noticed on the direct drive turntable I have the JVC, that if I tap on it's base I can hear a "thump" coming thru the speakers, what causes this and is it possible to stop it from happening? I read that this is common on DD turntables, and people have used isolation products to address this issue, I don't see how isolationg the TT from the cabinet that it is sitting on would help since tapping the TT itself causes the noise. Any ideas or suggestions? thanks

 

[TRC-911]

I know what you mean, you touch the player itself and it feeds back to the speakers, It's like you're touching the needle even when you're not, I hope somebody could shed some light on this as I would like to know a remedy as well

 

[bill]

grounding issues.
it is strange you should post this beacause this morning my jvc turntable was doing just this and i saw the ground wire had been attached to the chasis of the turntable by the previous owner.
i just grounded the terminal to the back of the reciever and it is fine now.
i am pretty sure what is happening is a grounding issue.

 

[ahardb0dy]

mine is grounded to the stud for the ground on the receiver but I will check it again tomorrow

 

[bill]

mine is grounded to the stud for the ground on the receiver but I will check it again tomorrow

check the other end of the ground inside the chassis of the turn table. it is possible for it to have become loose inside.

 

[ahardb0dy]

ok, thanks

 

[oldskool69]

Other than checking the grounding, you may have an isolation issue as well. If your direct drive is via the pin to platter (plinth) method, then check the motor isolation, bushings & springs. If the platter (plinth) acts as the rotor itself (i.e Technics models from the SP-10 up...) you will experience this far less thump/vibration (and explains why DJ's love Technics) than you would with a motor/rotor combo. Any type of disturbance or vibration can cause feedback noise through a turntable. The easiest solution is to place it on a concrete block with spiked feet.

(You can also get better isolating feet than what the factory offers for the housing.)

What you can check also is that your needle and cartridge are firmly locked in and aligned properly. As you know, a records grooves does not consist of perfectly smooth valleys and if out of alignment or loose, rumble and feedback are more likely.


But as we are mere mortals, we use ordinary racks which aren't vibration isolated.

 

[ahardb0dy]

I just threw the cartridge onto the head shell but I am looking at getting a new one which I will take the time to make sure it is setup properly, I had a record on last night and checked it and I didn't hear anything when I tapped on the base. Will see what happens after replacing the cartridge, thanks all.

 

[71spud]

I noticed on the direct drive turntable I have the JVC, that if I tap on it's base I can hear a "thump" coming thru the speakers, what causes this and is it possible to stop it from happening?

Patient = "Doctor, it hurts when I go like *this*. What should I do?"

Doctor = "Don't go like *that*"

 

[ahardb0dy]

that is so true, lol