gfong Posted April 19, 2015 Share Posted April 19, 2015 (edited) I have suddenly got a ground problem with turntable or a loose connection problem in bass bin woofer location. Problem: Walk up to system and can hear my footsteps coming through the bass bin area.Gently tap on carpet and can hear same noise through right speaker. Tried different turntables, interconnects, speaker wire and phono stages and nothing changed, same noise. I use a NAD integrated amp, La Scala speakers, REGA RP6 turntable with Exact cart, Graham Slee AMP 2 SE or a Bellari VP-130 phono stage and a Sony SACD player. Speakers sound perfect when using the SACD player, no noise just great sound from both. As soon as I use the turntable the noise is back, switched speaker cables and the noise followed the speaker which got me thinking it was a loose connection to the woofer or something but why would it not act up when using the SACD? Thought it could be a ground loop but do not have a ground on my RP6. I guess it still could be a ground loop as it only does it with the turntable but the more I eliminate the more it sounds like a speaker problem using it with the turntable. The left speaker and left channel are fine and no bad noise comes out but when switching wires it happens on the left side using the right side speaker. Any suggestions or test you could think I could do would be appreciated. Don't want to open up the La Scalla if I do not need to. Thanks Edited April 19, 2015 by gfong Quote Link to comment Share on other sites More sharing options...
oldtimer Posted April 19, 2015 Share Posted April 19, 2015 Do you get hum just by switching to phono and not stepping or tapping anywhere? That would be indicative of a ground issue to me. Otherwise it sounds like a feedback issue from your description. Quote Link to comment Share on other sites More sharing options...
gfong Posted April 19, 2015 Author Share Posted April 19, 2015 (edited) no hum in the system at all but at 1/4 volume when cuing the record and just before the song starts you can hear little noises that are not suppose to be there, it actually sounds like someone wiggling a wire but the music has not started yet. Just like the walking sounds, I actually do not hear footsteps but hear static with an echo behind it. When I tap the floor I get the same sound from just the right side speaker but when I try the right speaker on the left side it does it as well so that got me thinking it was just the one speaker Any ideas on how to rectify a feedback issue? This is killing me! Edited April 19, 2015 by gfong Quote Link to comment Share on other sites More sharing options...
Schu Posted April 19, 2015 Share Posted April 19, 2015 (edited) Do you live on a raised foundation? TT Edited April 19, 2015 by Schu Quote Link to comment Share on other sites More sharing options...
LarryC Posted April 19, 2015 Share Posted April 19, 2015 Do you think this could be mechanical feedback through your turntable, cartridge and tonearm? (I have trouble imagining how that could be.) Do footfall vibrations travel to anywhere within your system, including the interconnections between the TT and amplifier? Quote Link to comment Share on other sites More sharing options...
gfong Posted April 20, 2015 Author Share Posted April 20, 2015 (edited) I do live in a raised foundation and I am not sure what the noise is if it is mechanical feedback or not. I am going to video tape the sound as it seem I cant describe it correctly, be it a noise, loose connection, vibration. Thanks again all. Edited April 20, 2015 by gfong Quote Link to comment Share on other sites More sharing options...
WMcD Posted April 20, 2015 Share Posted April 20, 2015 (edited) I'm in agreement with Larry C. It certainly seems like something is microphonic in your system. Turntables can do that but so can vacuum tubes. Further, it could be a loose connection someplace and that is making the odd noises too. Let me suggest you try listening on headphones, even cheapo earbuds, to take the speakers out of the equation. It may make it easier to troubleshoot. One other thought is a bit oddball. You say the trouble follows the speaker? Let me call that the noisy speaker. I can't think of why that should be except . . . . Just maybe that noisy speaker is working properly and you do hear the microphonic effects. But the other speaker (the non-noisy one) is not working properly, which is why you don't hear it there. I was surpized once to find that one of my horn-loaded woofers was not working. In stereo reproduction it was not obvious. Therefore, let me suggest that you try using the balance control to check to determine whether each speaker is working properly. A final diagnostic aid would be a "mono" switch, if there is one on your amp / pre-amp. If the problem is in one channel and then goes to both in "mono" you'll know at least part of the issue is before the mono switch. But I think it is almost a given that it is turntable / pick-up related. Likewise, you might switch the turntable left and right feed to the pre-amp and see what that does. Let us know. WMcD Edited April 20, 2015 by William F. Gil McDermott Quote Link to comment Share on other sites More sharing options...
gfong Posted April 20, 2015 Author Share Posted April 20, 2015 Hi and thanks.. tried the headphones and it is in the right ear as well. Not as pronounced but I can hear it when I tap a little harder on the floor. I had already tried switching left and right and as stated before the noise follows the speaker. The noise I am talking about it not intermittent or changes in anyway, tap something and you hear it clear as day through the speaker. There are no tubes in my system now it is all solid state. So if it is turntable pickup related what are some things I can try to isolate or get rid of the noise? Thanks again. I will make a video of the noise I hear and post tomorrow, I am pissed at this tonight and not going to tackle anymore til tomorrow. Quote Link to comment Share on other sites More sharing options...
WMcD Posted April 21, 2015 Share Posted April 21, 2015 (edited) I'll leave the further work to those here who are turntable experts. I should have asked the typical questions. Did this system ever work without problems? Did you change anything just before the problem started? Are you saying the system makes the noise with the stylus not in contact with a disk? It seems you are saying so. When the stylus is on the disk it is not uncommon for there to be a feedback situation where vibrations from the speaker get back to the mechanical action of the stylus. Then, mechanical isolation is lacking and can be addressed. In the situation you describe, stylus hanging in mid air, it is probably a connection issue. Maybe the ground connection at the pick-up or between the pickup and the RCA feed. I can't explain why this follows the speaker though, unless there is something unique to it which transmits vibrations. WMcD Edited April 21, 2015 by William F. Gil McDermott 1 Quote Link to comment Share on other sites More sharing options...
gfong Posted April 21, 2015 Author Share Posted April 21, 2015 (edited) Thanks again William, yes the system worked flawless for 3 months, then I started rolling tubes in the Bellari Vp-130 phono stage. On the second tube try the sound appeared and I thought through reading that the tube may have been microphonic, I then went back to the original tube and the sound was gone. I then tried a Graham Slee solid state phono stage and the sound was still there but not as loud. I put it off for about 2 days and then switched back to the tube stage with the original tube and the sound was there for good. Important: I now 'only' use the Graham Slee phono stage and have tried one other brand new Graham Slee Era Gold V and the noise is still there. No tubes in system at all. The noise only occurs when the cartridge/needle is in contact with the record. When I lift the needle from the record the noise is not present. Not sure where you read 'stylus hanging in mid air,' but that is not the case. When I wrote cueing the record I meant when the needle is touching the LP. Edited April 21, 2015 by gfong Quote Link to comment Share on other sites More sharing options...
Marvel Posted April 22, 2015 Share Posted April 22, 2015 Is the cartridge matched to the phono pre? May be a stupid question, but it sounds like too much gain. 1 Quote Link to comment Share on other sites More sharing options...
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