Hum. Hmmmmm

[Pure_Brew]

I know there is some low level hum in my system but I would have to crank the volume knob with nothing playing to hear it so it doesnt bother me.

However I was trying to make a recording and I noticed it stood out on headphones and on the recording. Why would I get hum from the TT, if it's just plugged in to the pre even with no power cord plugged in to the TT to the wall.

If it's not even plugged into power, what would cause this hum? Bad rca's or internal wire? I guess it reminds me of having an adaptor cable plugged into a source input, like an RCA to mini, then touching the mini end and making noise. The guy I got the TT from did have replacement RCA connectors on it. It's likely part of the problem since one is a little loose....

 

[laatsch55]

Do you have the TT grounded directly to the ground screw on the back of the pre??

 

[laatsch55]

Loose RCA will cause an ungodly amount of noise problems---ESPECIALLY-- with a low signal source such as a phono cart.

 

[Elite-ist]

Hi Joe,

The RCA cables from the turntable, ideally, should be the shielded type. Ensure the turntable RCA cables aren't routed close to power cords. Do you have a second set of phono inputs in the preamplifier to try plugging your turntable into?

Nando.

 

[stuwee]

If the ground wire is correctly screwed into the back of the pre, you may want to look at the ground wire's routing internaly inside the TT (if this is possible), there may be a loose connection inside. Other than that, keep the cords seperated from the back and you may have to jiggle things around a bit to get rid of it. Some cartridges like the Grado's are know hummers when the cart's magnets get near the TT's motor, good luck...hum and RF interferance is a bitch and hard to irradicate sometimes, part of the fun of hi-fi

 

[orange]

Do you have a source of interference like a DVD player close by? Remove all other sources until you find what makes it and place them away from the TT. I have a Pioneer CT-3000 that hates DVD players.

 

[Pure_Brew]

Dammit it's the cartridge....

 

[speakerman1]

Did you swap carts?

Larry

 

[Elite-ist]

The AT cartridge is the cause of the excessive hum? Double-damn!

Nando.

 

[Pure_Brew]

I swapped headshell/cart combos. The AT70 on the original headshell is just fine. No hum, no motor noise, nothing. I could try the 440 on the original headshell but I need the alignment tool. I need one anyway so I'll get one from needle doctor for 6 bucks.

I still need to look at the bad solder job on the left RCA, loose connection. That's minor compared to this, more prevalent on the 440 but then I guess everything else is too.

At least for listening purposes I'm safe either way, but when I make my friends CD, I might have to go with the 70.

 

[speakerman1]

Will they take the cart back? On your IC try oak tree they have some part out Pioneers.

Larry

 

[Pure_Brew]

I'll ask but, I might send a letter to AT about it, see what they have to say. I can't hear it when I listen through amp/speakers, so keeping it won't be the worst thing. But boy I forgot how laid back the 70 is, nice with Jazz.

 

[speakerman1]

Is your arm grounded? The cart may be just more sensitive and may need the are grounded.

Larry

 

[Pure_Brew]

No idea but I could just make a contact with a piece of wire to ground and see what that does.

 

[speakerman1]

Would be a cheap fix for sure. Not easy but cheap. I have a bunch of 32 ga. Silver wire if you need some. It is solid not stranded.

Larry

 

[Pure_Brew]

You'd have to run that up inside the arm?

 

[speakerman1]

You may be able to ground it to the base. If you know which terminal is ground. That would be a lot easier.

Larry

 

[Pure_Brew]

I took a closer look at the table. I did try a probe to see if there were any changes and there weren't. However.... The motor is located directly between the tone arm and the spindle! That CANNOT be helpful.

Likely this is just not a match made in heaven, but since the noise is below my ability to hear it through the speakers, whatever. This cartridge sounds just to damn good to pass up. Maybe I'll try it on a different table, someday..,