Harley Rider Posted May 20, 2007 Share Posted May 20, 2007 Just wondering , i have feedbck when i listen to the turntable only. Its not crazy bad , you can listen to it at moderate listening levels but dont crank it up or ad to much bass . Should all my equipment be grounded together? I only have the turntable grounded to the Preamp. Should i ground the Preamp and Amplifier together and the turntable ? Also i have a older home with the standard 2 wire NO ground in the outlets . This will be a big job so it may be a while before i can change all the electrical . Does that have anything to do with it? Tanks for any help Chris Quote Link to comment Share on other sites More sharing options...
Dale A B Posted May 20, 2007 Share Posted May 20, 2007 Can you try a different location for the turntable? It could be picking up sound, rumble, or vibration from the speakers and amplifying it. Sounds like you have it grounded properly. Quote Link to comment Share on other sites More sharing options...
oldbuckster Posted May 21, 2007 Share Posted May 21, 2007 Can you try a different location for the turntable? It could be picking up sound, rumble, or vibration from the speakers and amplifying it. Sounds like you have it grounded properly. That's the first thing I'd try...................... Quote Link to comment Share on other sites More sharing options...
rjrbass Posted May 21, 2007 Share Posted May 21, 2007 I also agree that moving the turntable should eliminate your problem. I had the exact same symptoms; only at higher volume or with strong bass. Moving my turntable eliminated the problem, however the move required extensions be added to the turntable cables. The extensions added hum. I replaced the extensions with good quality, directional cables and the hum was eliminated. Directional cables generally have a shield which is attached to the negative or common wire, only at the source of the transmission. This shield is not connected at the delivery end of the cable, in this case in the amplifier or preamplifier end. Great for eliminating stray emf or flux from having signal lines in close proximity to AC power lines. Don't worry about not having a ground in your home electrical system, as most older equipment does not use it. If you do need a ground, as I did when installing a computer in an older home, I just ran a heavy copper wire from the main water pipe to the electrical outlet...no problems. Quote Link to comment Share on other sites More sharing options...
Harley Rider Posted May 21, 2007 Author Share Posted May 21, 2007 I wanted to thank everyone for the replys, i never would have thought that could be the problem . I have a set of 20ft RCA cables from my old car audio equipment. Ill give those RCAs a try , they are good quality . If they dont work then ill go buy the directional RCAs. Thanks again [] Quote Link to comment Share on other sites More sharing options...
IndyKlipschFan Posted May 21, 2007 Share Posted May 21, 2007 Can you move your sub to the other side? Does it do this with the lid on and off as well. Can u determine what is rattling?? Maybe something under your turntable feet as well? Just some suggestions.... Quote Link to comment Share on other sites More sharing options...
scott0527 Posted May 21, 2007 Share Posted May 21, 2007 It's always best to keep turntable cable runs as short as possible. If you do find moving the turntable solves your problem, then think about how to keep that turntable closer that 6 feet or so to your preamp. Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted May 21, 2007 Share Posted May 21, 2007 You are getting two different sets of responses because your question was not totally clear. Turntable Feedback is a result of a mechanical problem where the output of your speakers is vibrating the record/stylus interface causing the vibration to be amplified and sent to the speakers which repeats the loop and feedback is heard. The solution to this problem is to change the position of the speakers and turntable so the speaker output is not radiating on the turntable. Ground Hum is a very different problem. It's electrical not mechanical. Hum results from a poor ground, no ground to (oddly) too many grounds. The solution is generally pretty simple and involves proper grounding of the phono cartridge. One test is to take a wire long enough to reach from the turntable ground and touch it to a known good ground like a cold water pipe. When the hum is gone, you know the problem is solved. If your nearest ground is very distant, you'll need to have one run to your equipment stack. Quote Link to comment Share on other sites More sharing options...
Harley Rider Posted May 21, 2007 Author Share Posted May 21, 2007 Once again thanks for the input guys, yes it does it with the lid on or off----- i dont thyink its a ground problem now that i have these replys . It doesnt hummm its like the speakers start to rumble , they are moving when they shouldnt be .I havent had a chance to mess with it today. But i will try moving the turntable tomorrow and then go from there.. I took a ride toChampain IL today (the only place close that has high end equipment) Glenn Poor Audio, Champaign Audio ,a Good vibes which is the only klipsch dealer around i know of . Learned alot talking with those guys about the overall system. Had a good listen to what High end is all about! But the price factor will kill a guy lol. Thanks again eveyone for the replys Chris Quote Link to comment Share on other sites More sharing options...
consistent Posted May 22, 2007 Share Posted May 22, 2007 Hi, I have used squash balls under each leg this does reduce mechanical feedback. Tennis balls under your amp also works well. Cheers Quote Link to comment Share on other sites More sharing options...
mas Posted May 22, 2007 Share Posted May 22, 2007 You are getting two different sets of responses because your question was not totally clear. Turntable Feedback is a result of a mechanical problem where the output of your speakers is vibrating the record/stylus interface causing the vibration to be amplified and sent to the speakers which repeats the loop and feedback is heard. The solution to this problem is to change the position of the speakers and turntable so the speaker output is not radiating on the turntable. Ground Hum is a very different problem. It's electrical not mechanical. Hum results from a poor ground, no ground to (oddly) too many grounds. The solution is generally pretty simple and involves proper grounding of the phono cartridge. One test is to take a wire long enough to reach from the turntable ground and touch it to a known good ground like a cold water pipe. When the hum is gone, you know the problem is solved. If your nearest ground is very distant, you'll need to have one run to your equipment stack. Thanks Bob! As I was reading through this I keep wondering when anyone would address the actual nature of the problem and the confusion between conductive and electrical noise.. Also, I must admit to not being used the either the mechanical rumble or electrical hum/noise being referred to as 'feedback', but that is a semantics issue - albeit one that still has me a bit confused as to what exactly the 'feedback' consisted of as various solutions and actions seem to arbitrarily jump back and forth between both types. Regarding grounding issues, this will manifest itself most commonly as a 60 Hz 'hum'. Grounding problems with the arm, cartridge, motor, and interconnects can all be a source of this, and proper grounding techniques (& with 'directionally grounded' cables - w/ ground attached at the TT end only), etc. can all be a solution to this. This is most easily isolated by dividing and conquering,..connecting and disconnecting components until the problem ceases and can be isolated and remedied. As far as the mechanically inducted noise (conduction). This is either a result of physical conduction through the base which is directly transmitted to the arm and cartridge or it is a result of the transmission through the air of the sound waves themselves. The location of the turntable simply begs for this. In fact, I would be shocked if you told me that it wasn't noticeable! I would suggest moving your equipment rack as a whole. Place it between the speakers or further away from the speakers towards the back of the room. ANYWHERE but directly in front of your speakers!! In this location you may be able to mitigate some of the gross aspects of the problem, but the sound waves will still stimulate the turntable base and be transmitted via the cartridge. You have a situation that is akin to standing on a trampoline. Unfortunately, simply wearing different tennis shoes, while they may absorb some of the energy, are simply not sufficient to damp the action of the trampoline! And as such, simply providing a more compliant support will not solve this fundamental problem! [] Do the easy thing! Move the equipment rack to a location between the speakers! And save the money on all of the other 'minor at best' 'solved by money' solutions! BTW: I defy anyone to substantiate isolation under electronics (assuming only electrical processes and no mechanical processes!) having any effect on the generated signal and subsequent sound. And I have yet to see any electrical component ratings for g-force (other than impact survivability specs)! And I would love to see the documentation and verification of any information alluding to electrons becoming dizzy or suffering vertigo from vibration - - okay, okay, except for the special electrons that Monster keeps that routinely get lost going down the wrong conductor! If you want to physically isolate mechanical assemblies from vibration, fine. But the benefits of similarly isolating purely electrical sources are spurious at best. But they do make somebody allot of money! [:|] Quote Link to comment Share on other sites More sharing options...
bodcaw boy Posted May 22, 2007 Share Posted May 22, 2007 What did the turntable day? 1peter 3:9 Roy Quote Link to comment Share on other sites More sharing options...
Harley Rider Posted May 22, 2007 Author Share Posted May 22, 2007 Well the turntable is playing better, still has what ill describe as a light flutter when the volume is around 12 oclock position. It is 75% better . I moved it under the TV on the stand between the spkrs . That didnt work , a humm started happening about the 11 oclock position and if you left the volume up the hum got worst real bad ! So i moved it to the other end of the couch and used the coffee table to place it on, That works alot better , but you can still see the woofers flutter a bit at a good volume as i said at the beginning. I didnt have much wire laying around so i used a old 18 guage spkr wire to extend the ground back to the preamp. I know thats small but its all i had soooo... for now itll have to work. Any other suggestions , i feel as if this should play with no movement from the spkrs until they get the correct signal (correct)? Thanks again Chris Quote Link to comment Share on other sites More sharing options...
LarryC Posted May 23, 2007 Share Posted May 23, 2007 Well the turntable is playing better, still has what ill describe as a light flutter when the volume is around 12 oclock position. It is 75% better . I moved it under the TV on the stand between the spkrs . That didnt work , a humm started happening about the 11 oclock position and if you left the volume up the hum got worst real bad ! So i moved it to the other end of the couch and used the coffee table to place it on, That works alot better , but you can still see the woofers flutter a bit at a good volume as i said at the beginning. I didnt have much wire laying around so i used a old 18 guage spkr wire to extend the ground back to the preamp. I know thats small but its all i had soooo... for now itll have to work. Any other suggestions , i feel as if this should play with no movement from the spkrs until they get the correct signal (correct)? Thanks again ChrisI probably missed it -- what are you using to isolate your turntable from vibration? Tennis balls cut in half are supposed to be good, tho' I haven't tried it, but you clearly need something. Your music may be so loud that moving your table and electronics into the next room is the only answer. This has NOTHING to do with grounding, as others have noted, so I'd quit wasting time on that. It's not "hum," though it may sound like it to you. Some recordings may have a low-frequency fluttering signal, so to take that out of the chain for testing purposes, I suggest finding a recording that causes no -- or the least visible -- bass driver movement, and then use that recording to concentrate on getting the table isolated from picking up the sound directly, since that appears to be your problem. Quote Link to comment Share on other sites More sharing options...
djk Posted May 25, 2007 Share Posted May 25, 2007 Turntable feedback is just like microphone feedback. You turn up the volume or get it to close to the speakers and it will take off. "Flutter" is a different issue. 08-16-2003, 8:14 PM 247791 in reply to 247776 djk Joined on 09-01-2000 Posts 2,100 Re: Feedback Reply Quote Edit Favorites Contact "By the time it got tward the third track the woofer flutter was not even close to what it was on the first track"Warped recordpinch warp=8hzsaddle warp=1/2hzTone arm and Cartridge resonance8hz~14hzRIAA EQ curve boosts the LF at a 6dB/oct rate which amplifies all of the above.Particularly dangerous to vented speakers.Remove with high pass filter in tape loop or between preamp and power amplifier.20hz 18dB/oct 30hz 12dB/octVirtually all Audio Control products have an 18dB/oct 20hz filter built in, some also have a rumble reducer to get rid of turntable vertical bearing noise without rolling off the bass. Quote Link to comment Share on other sites More sharing options...
Harley Rider Posted June 4, 2007 Author Share Posted June 4, 2007 Well i decided listen to some albums tonight noticed that when you bump the lid ever so lightly you get a light thumpy like sound out of the spkrs , you dont get it with the volume down but it does get louder as the volume goes up. Even at very low listening levels you can get a good thump per say . Its like the lid but not the main body of the turntable is picking up things , can this be? Quote Link to comment Share on other sites More sharing options...
Harley Rider Posted June 4, 2007 Author Share Posted June 4, 2007 correction, i just double checked and you can just so lightly tap the lid or body and hear through the spkrs!!![*-)] Quote Link to comment Share on other sites More sharing options...
Dale A B Posted June 4, 2007 Share Posted June 4, 2007 Sounds like your TT is amplifying everything in it's path. I don't know if direct drive TT's are more susceptible to this than belt drive, but you may have to remove the lid, and/or place the TT on the floor. Why did this problem just develop - did you just get the TT recently? You have to keep experimenting, hoping it clears up or give up the ghost and go digital. Quote Link to comment Share on other sites More sharing options...
JJkizak Posted June 5, 2007 Share Posted June 5, 2007 I remember that problem a long time ago. Some people hang the TT from the ceiling with chains for isolation. I believe that some cartridges are more of a problem with feedback than others. Those real low speaker excursions with no sound output could mean you have a cheap amplifier. Or maybe it is too good and the low end should be restricted. I forgot about all of those problems long ago after I switched to SS. I just had to say that. JJK Quote Link to comment Share on other sites More sharing options...
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