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What is the "usual" source of hum between a turntable and phonp-preamp??

I just purchased a U-Turn Basic TT with an acrylic platter and cork mat with an Ortofon 2M Red cartridge. The table is plugged into a Moon Audio LP-110 phono pre-amp. Moon Audio does recommend to isolate the box away from the turntable. I have currently placed it on a 21inch formica platform stand.  The hum is most audible in the lead out groove, and between tracks.  The sound is very good, BUT I can still hear an undertone of hum when the volume is half way, that is between  55-60 steps on a volume control calibrated from 1-99.  The pre-amp is a Conrad Johnson PV-14SE which the Moon phono box is plugged into

I aware that the hum problem can be caused by the phono cable of the turntable ( which is somewhat cheap) or the connect IC which  is one of the Canare cables which cost $40.00 to $50.00. It appears well made. The   U-Turn TT rep informed me that the left channel input on the table functions as a built in ground.  The Moon box has a separate grounding screw which I am not using.   Thank you,   S.J

  

sunnyjim
yogiboy's avatar
yogiboy
2,678 posts
 
Return it and get something else within that price range. Something like this!
http://www.needledoctor.com/Rega-Planar-1-Turntable?sc=2&category=353
sbank's avatar
sbank
2,038 posts
 
"required getting a track force gauge if I decide to change cartridges"

If you aren't willing to invest $11 in a digital stylus forge gauge from eBay and set the force correctly (which takes about a minute) then you really shouldn't be listening to records. Numbers on a counterweight are never accurate enough for any repeatability nor for tuning setup of any quality cartridge. 
Same thing if you aren't willing to vacuum clean your records and put them in good inner sleeves after cleaning. 
Good vinyl playback doesn't have to cost a fortune, but it does take more energy than pressing play. Some find the involvement & ritual satisfying tasks. If that doesn't suit you, go hi rez and stick with digital. Cheers,
Spencer
sunnyjim OP
884 posts
 

To sbank, I just knew the comment about the stylus force gauge was going to incur flak from some members.  However: 

I can and would easily purchase the $14 Shure Force gauge

If numbers on tracking force  tonearm  counterweights are  inaccurate and unnecessary why do so many TT manufacturers provide a calibration ring with counterweight or etched on it..

I do clean my records before each play with a Mobile Fidelity Liquid and brush, and then when the LP is dry, use a Hunt record brush to finish off.

I place my records in MF treated  inner sleeves to prevent deterioration of the vinyl, scratches and dust

I cannot afford a vacuum record machine, but am considering the Spin-Clean "Starter Kit" for record care at $79.00

I mentioned in previous analog related threads, I only play LP's 20% of the time.

So,  I am not the lazy analog slug as SBANK suggests.

Lastly, to all members, let me ask: would the new Project RPM-3 with Sumiko BP-2 MC  be a worthy upgrade from U-Turn TT as described above??   There is internet audio vendor offering a mint demo at a 30% discount from the retail of $999.00

Thanks to all who have responded so far.   SJ 


sbank's avatar
sbank
2,038 posts
 
@sunnyjim I certainly don't intend to insult you and never called you or anybody else a slug. I'm not here to make enemies. Your last post implies that you are less undaunted by the steps needed to get decent analog sound than I had realized. So I am glad to understand that now.

I applaud your effort with the LP cleaning brush, but feel that the Spin Clean would be a great deal more effective! 

There's nothing wrong per se with the Shure gauge and I used one for many years, but for even less money the digital ones on eBay(they all look like the same one but with different names(mine is Neoteck NTK002) is easier to use, more accurate and also safer in terms of less chance of damaging your cantilever/stylus. Every time I use it, I think that I should have changed out the Shure for this sooner.  Cheers,
Spencer
alpha_gt
155 posts
 
Without playing a record, but platter spinning, move the arm from its post to the spindle, and back. Does the hum increase as the needle gets closer to the spindle? And quiets down as it gets back to the rest post? If so, I've had this problem before. It's feedback from the motor. On a low priced table I had, Project Debut. At moderate volumes I could demonstrate this effect, the small motor is unshielded and under the platter, too close to the cartridge. And the closer the needle gets to it, the more hum I heard. It really wasn't that bad, only heard it as you say, in between songs, so I lived with it until I upgraded to a nicer 'table. Not much can be done about it, just an inexpensive 'table design. If it's that objectionable then perhaps you should invest a bit more money into a nicer 'table? Or a good deal on a used table? 
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