2. analog
  3. 177351-1662

How best to eliminate LP warps

I own about 2500 LPs, and I like to think they're flat.  Furthermore, I espoused the view that warped LPs ought to be discarded.  But lately I have found 2 or 3 of my LPs that do have warps but sound too good and are too precious for the music recorded on them to throw away.  So I am in the market for ideas on how to remove warps.  I am aware that there was a device on the market that looked like a large waffle maker, to be used for warp removal.  I think Furutech made it, but I never see it advertised these days.  I am also aware of the DIY method of placing an LP between two glass plates and heating the ensemble.  The question there would be how hot and for how long?  Any suggestions are welcome, especially opinions on the efficacy of the Furutech.  Thanks.  Please no comments on vacuum hold down; I think it's a great idea but none of my five turntables has that feature.

lewm
mijostyn's avatar
mijostyn
8,221 posts
 

@pryso , very true about warps and dishing. I send the dished records back. It is almost impossible to seal the convex side.

In order to hear the warp easily you have to have some steady tones like a cord held on a piano. Sine wave test records really demonstrate the effect of warps and off center spindle holes. When a turntable compensates for everything except the offset spindle hole which there is no compensating for, with vacuum clamping and rock solid speed control there is a sensation of solidity which greatly adds to the illusion. I can not tell you if this is psychological or not as I have not performed that experiment. It seems to me to be quite obvious but, out brains are powerful items and you should never write them off. 

terry9
2,229 posts
 

@pryso 

Actually, a reflex clamp consisting of a clamp or weight plus a thin beveled 'washer' over most of the label, can mostly rectify records which are dished, in both directions.

pryso
1,909 posts
 

@terry9, yes something similar can work for some dished records.  However I had a Kuzma table  which utilized a washer (diameter no more than a quarter) and threaded clamp and I only had partial success with that.

But you mention a thin beveled washer over most of the label.  I've never seen one like that.  To me, to be effective it seems the clamp must have a greater diameter than the washer for it to be able to push downward on an unsupported portion of the LP.  So I don't understand how a washer that large could work?

slaw's avatar
slaw
20,433 posts
 

I’d like to see a picture of that washer. It’s shape/effect makes sense to me as long as the end of a record ( inner grooves) makes good contact.

pindac's avatar
pindac
2,433 posts
 

@drbond In relation to your inquiry about eccentric rotation, the Link might prove to be latest commercial device on offer to confirm the amount of Off Axis eccentricity being produced.

It would be good to know if this device is also able to measure the Spindle being rotated in a Off Axis Rotation.

 https://ds-audio-w.biz/products/563/?fbclid=IwAR041VevFGPZEx1e_igdoMNhhEUbOFKiQvBaK3ktZM-ocM63_X6sAnehJ98  

More to discover