Dual 1019 and massive plinth

[Nat]

I wonder if anyone has given the Lenco/Garrard 301 massive plinth treatment to a Dual 1019 or similar heavyweight changer? Was it a similar step up in sound quality?

 

[ejman]

I'm sure it would help to mass load a 1019 (or 1219) but the problem with the 1019/1219 is that in order to accommodate the auto changer mechanism it uses whats basically a mini bicycle bearing for the platter. This bearing is orders of magnitude noisier than the single ball bearing in the Lencos or Garrards. Put a stethoscope to the top plate of a 1019 and give it a spin. try the same thing with a Lenco and you'll hear a significant difference.

 

[voltcontrol]

Do a Google picture search, you'll find stuff like this;

If you intend on keeping the stock arm I'm wondering if it will make sense...

 

[Nat]

Certainly a single ball should be quieter than a ball race, but a high quality ball race in good shape can be quite quiet -- I don't think noise is much of a problem for most Dual users. I assume that the main noise source that a massive plinth helps with is the motor, but I was thinking that it might be helpful with the various resonances of all the parts associated with the auto mechanism, but also the bearing.

 

[audiojones]

I assume that the main noise source that a massive plinth helps with is the motor, but I was thinking that it might be helpful with the various resonances of all the parts associated with the auto mechanism, but also the bearing.

The motor is attached to the deck of the turntable with rubber couplers and to the platter itself with the rubber rim drive wheel. I would think that these would transmit noise from the motor to the playing surface and tonearm regardless of the plinth mass, no? Or does the plinth absorb the noise generated by these components because of it's mass. Just curious, because I thought the heavy plinth idea was to absorb noise and vibration generated outside of the turntable itself. :scratch2:

 

[beatcomber]

I lined the United Audio base of my 1019 with Mortite rope caulk, and it seems to have tightened the bass response.

 

[Nat]

My interpretation of the massive plinth idea is that with idler tables (of any sort, manual or changer, I would guess) the motor is isolated from the top deck and the platter by rubber grommets and the idler. But that isolation is only relative, so some gets through. If what gets through has to vibrate not just the top plate, but another twenty pounds (or whatever weight) of mass, the resultant vibration is going to be way less than if it just vibrates the top plate. Just clamping down on the original base wouldn't do much since the mass of the original bases was very low, and the boxy shape would probably add a resonance to the vibration. Massive bases are an obvious solution, but not a cost effective one, shipping wise, so manufacturers wouldn't be eager to market them.

 

[ejman]

My interpretation of the massive plinth idea is that with idler tables (of any sort, manual or changer, I would guess) the motor is isolated from the top deck and the platter by rubber grommets and the idler. But that isolation is only relative, so some gets through. If what gets through has to vibrate not just the top plate, but another twenty pounds (or whatever weight) of mass, the resultant vibration is going to be way less than if it just vibrates the top plate. Just clamping down on the original base wouldn't do much since the mass of the original bases was very low, and the boxy shape would probably add a resonance to the vibration. Massive bases are an obvious solution, but not a cost effective one, shipping wise, so manufacturers wouldn't be eager to market them.

Yup, I think you nailed the rationale behind massive plinths pretty good. I actually bought the plywood and MDF to build one for the 1019 that I converted to a manual model after it was just about destroyed in shipping but it's taking its sweet time in making it to the top of the to do pile.

 

[audiojones]

Thanks for clearing that up! I thought the plinth mass was primarily to isolate from outside noise sources such as speakers and footfalls, but the idea of absorbing chassis born noise through it's mass makes a lot of sense. I regret selling my 1019, and building a high mass MDF plinth would have made a great winter project that would have paid off for years to come.

 

[beatcomber]

Do a Google picture search, you'll find stuff like this;

I don't care how good it may sound, that is just WRONG! :thumbsdn:

 

[ejman]

I don't care how good it may sound, that is just WRONG! :thumbsdn:

Yeah somehow it doesn't float my boat either