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Help deciding which TT

A little background.

I currently have a Rega RP1 w/Ortofon 2M Blue. It seemed great until I added a subwoofer. The sub is exhibiting woofer pumping when attempting to play vinyl. The problem even occurs if I place the needle on a record without the motor running, and then increase the volume. As the volume increases (again, the patter is not moving), the subwoofer (Martin Logan Grotto I) will start to pump. Eventually the sound becomes audible.

That IMO eliminated any motor, or bearing issues.

I've moved my TT to a wall shelf which seemed to have greatly reduced the pumping, but it's still present. I'm at the point where I'm thinking about purchasing a higher quality table. Here are some options I'm considering.

1) Brand new Clearaudio Concept w/ Clearaudio MM $1600
2) Demo Rega RP6 w/Exact Cart (full warranty) $1500
3) Lightly Use VPI Scout JR w/Ortofon 2M Black $1300
4) Used VPI Traveler V2 w/2M Black (200 hrs) $1000

I understand that I may have still have the same issue, but I'm hoping a better table will reduce/eliminate the issue. Any thoughts on the above tables?

Thanks
mustangjeff
stringreen's avatar
stringreen
6,472 posts
 
Another avenue of concern is a grounding issue. If the turntable is not running, I'm wondering if feedback is the problem. Do all the grounding tricks....eliminate the 3rd pin of the sub via a cheater, reverse the plug, using an extension cord, plug the sub into an outlet at the other end of the house, etc. When you find the troll, you then can figure out how best to fix it. Let us know....
czarivey
5,946 posts
 
I'd recommend waiting one year till new Technics DD. It may be sold at your price range hopefully.
mustangjeff OP
30 posts
 
Thank you everyone for your ideas.

It's an odd thing.

As I mentioned, just having the needle dropped on a stationary record and turning up the volume level is enough to kick in the rumble. The room is perfectly silent while doing these test.

What's interesting is that I can actually dial the volume up louder when the patter is spinning and music is playing.

If I turn up the volume with the tonearm in it's resting place, I get zero rumble/woofer flapping. I use a zero dust to clean my stylus. If I lower the stylus onto the zero dust, and then increase the volume I also get no rumble/woofer flapping.

The subwoofer is connected to my Anthem MRX HT receiver via LFE connector. No issues with digital sources of course. My phono preamp is a Rega Mini Fono A2D.

I created a custom grounding wire awhile back that connects the bearing well on the Rega to the Mini Fono A2D. I found that it eliminated some HUM I get in the Winter when the air is very dry. Connecting and disconnecting the wire makes zero difference.

If the issue is a grounding problem, it seems like the source is the tonearm itself. The RP1 doesn't have a separate ground wire for the arm. It's supposedly grounded through the RCA connector.
noromance's avatar
noromance
9,840 posts
 
It is acoustic feedback from the sub into the turntable body...bearing...platter...stylus. Put a slab of granite under the TT on the wall shelf.
zd542
5,339 posts
 
"The subwoofer is connected to my Anthem MRX HT receiver via LFE connector. No issues with digital sources of course. My phono preamp is a Rega Mini Fono A2D."

You should only use 1 LFE connection. If you connect IC's to the LFE out on your HT preamp, the other end should go to the line level input on your sub, not the LFE input. Try that first.

You may also want to try lowering the gain on your phono preamp, as well as checking the gain on the channel you are plugging it into. A lot of theatre processors have that ability. Also, I'm assuming that you are using the analog connections on your phono pre, and not the USB option.
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