2. analog
  3. 1441287058

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

Showing 6 responses by zd542

zd542
5,339 posts
 
What type of phono preamp do you have? You may be able to make some adjustments that may help fix the problem.

Since the problem started when you added the sub, I don't see why the problem can't be with that also. How do you have it connected to your system? If you're using an LFE output on your preamp, do you also use the LFE input on the sub?
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.
zd542
5,339 posts
 
"I don't think the Rega Mini Fono has the ability to lower the gain on the analog connections. I think the gain control only works with the usb port."

You can sometimes control each input on a HT preamp individually. I keep coming back to this gain issue because 5.5 MV seems pretty high. I haven't uses a MM cart in years, so I guess that could be normal for them. The highest output cart I can remember having is a DV 10x5 at 2.5 MV, and you needed to set the phono pre on MM to use it.

Maybe try fooling with the xover on the sub. See if you can set it to have a limit on how low it will go. It may be having a difficult time with really low notes, and that distortion is somehow effecting the system. Also, it wouldn't be a bad idea to try connecting the sub normally, without using the lfe, and any other type of EQ/Room Control processing.
zd542
5,339 posts
 
"2) Pickup a Phono preamp w/subsonic filter, or purchase a KAB RF1. The RF1 just seems expensive at $179 when I can pickup a Pro-Ject Phono Box DS for a little more money. I'd Consider the Cabridge Audio 651P as well, but I don't know the specs of it's subsonic filter (where it starts to filter and how steep of a slope)."

I believe your sub already has one. Use it to block the lowest frequencies. It will probably take some experimenting to find the right setting.
zd542
5,339 posts
 
If you want to buy a new TT, by all means get one. But you shouldn't be forced to get one over an issue like you are having. If you try some different settings on you sub (including not using the LFE connections at all), and some isolation devices, you should be able to get everything working.
zd542
5,339 posts
 
"A quick update. I had the stylus sitting on a stationary record, and turned the volume up to the point where the subwoofer started to slightly pump and the sound (low level rumble) was just audible. I gently put my hands under each side and exerted a slight lift upwards. The rumble went away. I didn't have the TT completely lifted off the maple shelf, but I was in essence making the TT lighter."

Try that again. Do everything exactly the same, but don't lift.
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