Turbulence in headshell/cart/stylus..skips and vibrating speakers

F

fabchef

Well-Known Member
hi gang, having this odd situation with my older Akai TT. It happened a few days ago. when playing the record at a low volume, it's ok. When raising volume the headshell starts to shake a bit casing the stylus to skip, as well, the speakers are moving (vibrating) at a fast speed. i tried changing records and most of them are doing this. i rechecked the tonarm weight and anti-skate and are where they should be. when i switch to the tuner, there is no issues. any ideas? the stylus in not old (rega carbon).
thanks
fab
 
Register to hide this ad
Others will chime in with better answers, but I can think of two possible causes. The speakers pumping like that are a symptom of either

1) big time acoustic feedback causing the TT to vibrate, which the stylus picks up, and then amplifies it.

2) You say it's an old TT. Could be the platter bearing is running dry and needs lubrication — when that happens, the metal-rubbing-on-metal causes audible rumble, and again the stylus picks it up and amplifies it.

The fact that you don't hear it at low volume is consistent with either theory.

You can confirm, or refute, the feedback theory by moving the turntable or isolating it in some way. If that has an effect, then it's probably feedback.

If it has no effect, that points to bearing-rumble as a likely cause, because the bearing (and it's rumble) goes with the turntable no matter where you put it or how you isolate it.
 
Bimasta, good theories, I will try torelocate. Btw..its an akai AP-206 direct drive tt. The platter seems to bemoving smoothly. I can't see thebearings underneath. If it is bearings, what do iput? Mineral oil, orgrase? Thanks, fabs
 
Try moving the turntable and report back. It sounds like acoustic feedback into the turntable from your speakers. This happens with the speakers are too close to the turntable. If your receiver has a headphone jack, plug in headphones, turn off the speakers and I expect you won't have any feedback and it will sound fine through your headphones.
 
Jeff, great point, will try it with headphones, didn't think of that one. I think it might be the bearings, as i've used the table before at louder volume with no issues, and it has bigger, spirngy feet. ILLINI...i'm not sure on cart, but it has a rega carbon stylus.
ALSO, for fun,i decided to change out the TT with my spare, trusty, dual 505 (with springy table). It works flawlessly, absorbs everything..bass and even heavy footsteps.
QUESTION...if indeed it would be the bearings, would it not rumble straight off the bat, regardless of volume???
 
update: so with using only my headphones, i put on a record that i recently picked up used, which i'm thinking was recorded HOT, cause on both TT's there was this fluttering effect. I then put on some jack johnson and played it back on both TT's and no flutter. One thing i did observe was a bit more fluttering, with the speakers on at a higher level...i guess it's seeping in? maybe i have to move speakers away?
one thing i don't know how to fix, if possible, is that with the Akai, it's so sensive to any minor bump or footstep around it and skips...should i add more weight to the tonearm? thanks gang. fab
 
fabchef said:
QUESTION...if indeed it would be the bearings, would it not rumble straight off the bat, regardless of volume???
Click to expand...
You wouldn't hear it at low volume, unless it was really grinding, and it doesn't seem that bad since it's only been happening lately. And yes it will get louder as you turn up the volume. The rumble itself is at a constant sound-level, so it may be inaudible at low volume, but goes up when you turn the volume up.

As for fixing it — first try jeffpaletz's headphone idea with speakers off, it's a good idea. If it's bearing rumble, you'll hear it through the phones, and it will go up/down when you turn the volume up/down.

If we're sure it's the bearing, then we'll talk about fixing it. Good luck, and let us know.
 
Update#2: ok so I tried jack johson again and turbulance was present at higher vol. I changed stylus to a spare dual dn230, it was better with slight turbulance at high volume. I thought maybe phono input, so I used a phono preamp and still does it.
 
update#3...after trying different possibilities, i tried to move the speakers abit more apart and away from the wall. I also took off the spikes underneath and put little felt pads, seems to have done the job! thanks gang.
fab
 
You must log in or register to reply here.
Back
Top Bottom