Excessive noise/ground problem turntable and/or Pre stage

gfong

Gear plugged into APC 10 Power conditioner: NAD C 356BBEE integrated amp, REGA RP6 turntable motor, Either pre stage Graham Slee or Bellari VP-130 (same noise from both.)
I have also plugged all into a power bar and then directly into the wall with no change at all. Interconnects used are Atlas and REGA is permanently attached to table. (interchanged cables with 3 other types and no change)

Noise from system: Walk up to system and can hear my footsteps coming through the speakers clear as day, go to sit on floor in front of stereo and can hear the sound from that. Sitting 12 feet away and stomp on carpet not hard enough to skip record and can hear through speakers. Cue record for first track and can hear same type of noise like I was walking but fainter. Gently and I mean gently tap in the carpeted floor in front of stereo and can hear clearly through speakers (very loud compared to my light tapping.)

System produced no noise except a bit of hiss from pre stage before I started changing things around. I changed tubes in my Bellari pre stage and noticed this after I used one of the new tubes. It was not that bad but could notice it. Changed back to the old tube and the noise went away. Put Graham Slee pre stage in and noticed the same sound but was not near as loud.

Now, no matter what pre stage I use or tube I put back into the Bellari the noise is constant and loud. I disconnected my SACD player so to eliminate any extra power cords or interconnects and that did not do anything.
The only thing that slightly reduced the noise was using the rumble filter on the Bellari but it only dulled the sound that I described before.

I know I must have done, broke, or changed something in the mix but I'll be damned if I can trace or find it. I have tried grounding things to one another, changing interconnects, power cords, pre stages and am at wits end on fixing this.

My REGA does not have a ground point on it as it is grounded through the RCA cables and I have changed them going from the pre stage to the amp. Can not change the REGA table cables as they are fixed.

The sound is not a hum or high pitch noise, it is more just transferring the sound from the floor through to the speakers.

I do not have any ground wires attached to any of the equipment as I have not required any before. I did try to ground the REGA PSU to the pre stage(s) and also tried between the pre stage and the APC 10 power conditioner and no go.

Any suggestions would be appreciated.

gfong

Tried my old turntable and identical noise. I forgot to put the ground wire on my Pro-Ject turntable and as soon as I turned the volume up I got normal hum from the speakers that I would associate with no ground wire connected . Connect my ground between the table and the Graham Slee pre stage and the hum went away which is normal. But the noise I am trying to get rid of was identical and still there even with another turntable. I switched inputs on the amp and that did not work. I'm lost lol!

voltz

well I think you eliminated the TT and I think you eliminated the phono amps also as not being the problem. (unless its ground loop) did this just start happening?

Can you plug the phono amp into one outlet and the amp directly into a different wall outlet? and then maybe a different set of Analog cables?

gfong

Started happening when I changed the tunes out on the phone stage. Tried the different sockets and interconnects and still the same. Will tackle this once I get back from Daughters wedding.

Upstatemax

Sounds like you need better isolation for the TT to get rid of the footsteps...

For the hum, is this a dedicated AC line or shared?

hochpt21

Gotta be the new tubes, right?

nooshinjohn

sounds like the new tubes are a bit microphonic. try some tube dampers...

specd_out

Seems like you need more weight on whatever your turntable is sitting on. A better plinth with some isolation may help. I use two maple cutting boards with blue tack in between to help absorb vibration. I have about 8 13"x13"x1/2" granite tile on my rack to weigh it down. Foot steps can be heard but you have to be stomping pretty hard.

voltz

Did you say the noise was there with both the Graham Slee & the Bellari?

As the Graham Slee has no tubes> wasn't sure if i read it correctly

gfong

Okay here it is.. No hum in the system at all. Noise or vibration with the Bellari which is a tube pre and the same noise/vibration using the solid state graham Slee. So I think I can rule out both pre stages. As far as isolation the turntable is sitting on a 2 inch maple board with cork/rubber pads under the four corners.

This is the important part... everything worked fine before I started changing tubes and pre stages. Now whatever pre stage or turntable I use the noise/vibration can be heard clearly through the speakers. I think maybe more from the right speaker. I am going to completely dismantled everything and re connect with different interconnects and power cables. Going back to stock everything and see what happens. Thanks again for the advice

mhardy6647

Everything sounds like microphonics -- tap the tube(s) with a stick (a Tinkertoy is the time-honored vacuum tube electronics repair-person tool for this) and see if it/they ring like bells. Keep the volume fairly low when you do this.

Some tube types are fairly notorious for microphonics. Actually, if you sing into a badly microphonic tube, it can and will pick up the vocal.

Polkie2009

mhardy6647 wrote: »

Everything sounds like microphonics -- tap the tube(s) with a stick (a Tinkertoy is the time-honored vacuum tube electronics repair-person tool for this) and see if it/they ring like bells. Keep the volume fairly low when you do this.

Some tube types are fairly notorious for microphonics. Actually, if you sing into a badly microphonic tube, it can and will pick up the vocal.

This makes the most sense mhardy.

gfong

Yes I agree with the microphone tube but the Graham Slee 2 SE pre stage is solid state and I get the same noise/vibration.

gfong

Had time to mess with everything and it was looking more like a speaker problem then anything else.

The noise is coming out from the bass bin of the speaker positioned on the right. Switched speakers left to right and same noise in any position I put 'that' speaker in. Tried a little bookshelf speaker and no noise from it.

I was guessing there was a loose connection in my Klipsch La Scala speaker but then I remembered that it does not occur when I play my SACD player... I am so lost on this now. (I still say it is the speaker somehow though)

Should I dive into the La Scala to see if any wires are loose? Why would it sound perfect running it with a SACD player.. makes no sense.

Back to the drawing board!

gfong

This may be a better way to describe what is happening now.

Klipsch La Scala speakers and I thought I had narrowed it down to one speaker as the noise can be only heard through the bass bin but then I thought why doesn't the speaker act up when I play the SACD player. The speaker sounds fine and nothing at all is wrong except when using the turntable. When using the turntable the speaker on the right has the bad sound and when switching left and right the bad sound follows the speaker not the 'right' channel.
That is why I thought it was the speaker but if it works fine with the SACD player I am lost?
Can a speaker pick up noise or vibration only through one speaker whether it is on the left or right channel and through different inputs but only using one source the turntable? That is what it seems it is doing.

gfong

Update, took the big ole 15 inch woofer out of the La Scala and me thinks I have a voice coil blown. I don't know if this occurred during, before or after all the vibrations that I described but I am going to get this rectified and move on.

voltz

Ouch! sorry to hear that Greg, I've always wanted to hear them La Scala's.

gfong

Well don't come over here cause mine sound like shite now! ha ha ha ha! gotta laugh eh!

Dennis Gardner

It sounds like you are experiencing a distortion at low volume that most likely disappears once you push the volume up to normal levels. I have had this happen on worn out woofers in my pro audio speakers. With spoken word, they had a rattle, but when driven with music that got them moving a bit, the rough edge was gone. The reason your footsteps seems to cause it was that with the lack of foreground music in the signal the small movement of the woofer caused a small rub of the coil on the magnet assembly. Time to replace or recone.

gfong

Thanks for the explanation. Going to check the price of reconing both woofers before ordering a new K33 Klipsch woofer.

gfong

Ordered from the Klipsch factory a new K-33-E 15" woofer. Should be here in 5 to 7 days from Indianapolis. Once installed will give it the proper break in time, Klipsch says 75 continuous hours of operation and it should sound like the 36 year old K-33-B that is in the other speaker. If it does not I will order a new one for the other speaker. Thanks for the suggestions and tips, reconing was just too costly and 2 hours away to boot.

gfong

All back together and working and sounding great.

While I was waiting for the woofer I updated the caps on the La Scala crossovers.
Happy with my upgrades and back in the saddle with my 2 channel rig.

voltz

Looking good Greg, Now you know those new cap's are going to need some serious burn-in time! If you weren't in Canada I say I'd be happy to burn them in for ya and getting back to you in a few months

gfong

Ha Ha, yea shipping kills the even lending them out gesture!

Thanks again for the help and the knowledge... awesome people on here.