2. analog
  3. 127418-83820

Can an old Thorens Table be "Over Dampend" to the point where sound is adversely effected?

I am sure this topic is not new but I would like a new take on it...So the question is: Can one Over Dampen an older suspension chassis Thorens like a 125,145,160,166 etc.? I am only (in this post) regarding the exposed inner wood of the plinth like the base and inner walls. I have heard in some venues that it is easy to over dampen and KILL the dynamics of one of these older tables...Are they referring to more of the damping of the motor, platter, suspension parts etc. basically the metal parts or any damping? What are your thoughts?

Thanks!
rikintpa
mattmiller's avatar
mattmiller
1,555 posts
 
A lot of people like to dampen these older Thornes tables either on the interior of the wooden plinth or all over the inner metal spring board, and arm board, they use things like "Blue Tac" or that Dynamat stuff in car doors. It will kill the sound and rob the life out of the music. The best thing you can do is make sure the springs are working properly and lubricate them and if possible remove the deteriorating foam plugs in the springs. And have the table on a good non resonant level shelf. I own a TD160 and it has been semi-rewired (Morrow Audio pwr/ic from wiring block, stock tonearm wire to block) this really opened up the soundstage and added much needed detail. The biggest upgrade to the sound was putting a Grado Prestige wood body on the TP16 tone arm (match made in heaven).

Matt M
rikintpa OP
20 posts
 

Thanks all

 for all the input! 

So here is the "whole story":  I actually dampened my 125 Long Base on the new Birch Base Plate and all interior walls that I could safely reach It was quite a bit and I was quite proud of myself and my work, that was until I played my first record...a record that I listen to often and know very well.  What can I say the sound lost it's dynamics, Soundstage and worst of all it's verve!  I was nervous I jacked up my stylus or worse my new pre-amp (EAR-834P) it was THAT BAD, so I tried a few other albums that I know to no avail and it was all BAD!  So I re-traced my steps and it came back to the dampening job that I was so proud of.  So the next step was to open her up and remove all the damping that I did, put her back together and tried listening again and, thank the Audiogods, the magic had been restored!  The same Dynamic expansive soundstage was back and most importantly the verve was restored!  I was very surprised that the dampening affect on the sound of my 125 was so different than the sound on my 145!  The 145 came alive while the 125 died.  So the lesson here is damping DOES affect sound and one size does not fit all so let those with direct experience on your particular project be your guide!  And yes I was told it [damping] was not necessary on this Table by its restorer but I did it anyway...Lesson learned.

halcro's avatar
halcro
2,664 posts
 
Your experiences should be a salutary lesson to some, about the dangers of 'over-damping'.
Here is a quote from a learned dissertation on vibrations:-
Damping is always present to some degree in any real system. Without it, there would be no way to limit the amplitude of a resonance. The materials employed to provide damping, the ratio of these materials to those elements that need damping, and the method in which they are applied, all determine how effective any scheme is at reducing broad-band vibrations. However, you cannot mechanically "over-damp" a structure or component that is not designed to be a transducer. You can over-damp some circuits electrically; you can over-damp the "Q" of a speaker as well. You can also over-damp structures associated with a phono cartridge: a tonearm, plinth, etc. But you cannot over-damp a preamp's chassis or an equipment rack.

Note the 'over-damping'revelations concerning phono cartridge, tonearm and plinth.
Despite what some here have been propagating for years....over-damping of turntables, arms etc is not only possible, but can deleteriously affect the sound.
rikintpa OP
20 posts
 
And on that note...May we ALL learn something here...Thank you "halcro".
atmasphere's avatar
atmasphere
12,174 posts
 
A lot of people like to dampen these older Thornes tables either on the interior of the wooden plinth or all over the inner metal spring board, and arm board, they use things like "Blue Tac" or that Dynamat stuff in car doors. It will kill the sound and rob the life out of the music.
Despite what some here have been propagating for years....over-damping of turntables, arms etc is not only possible, but can deleteriously affect the sound.
You do have to be careful. But damping a plinth usually dosen't get you in trouble, unless that plinth is so floppy to begin with that all you really did was to change the resonant frequency!

One area where people get in trouble is damping the arm board. The arm board has to be rigidly coupled to the plinth to insure that it moves in whatever plane the plinth moves (a corollary is that if the arm board is of a different material from the plinth it can introduce a coloration all by itself). If you've damped it incorrectly, that may not happen and the result is that the pickup will interpret the difference between the plinth and the base of the arm as a coloration. 

The other problem you have to really be keen on is to make sure that you are not treating the turntable as a sort of tone control to synergize with weaknesses elsewhere in the system.
More to discover