Vibration Question


Warning to the sensitive: involves tonearm pods.

I know this topic is beyond the pale to some, but my tables cannot take a second tonearm (once upon a time, though, they did), and I enjoy variety in cartridges. I have bought four pods so far from Lee Drage at Acoustand, two plain and two with built in micrometer VTA adjustment. But I discover the airspace around the tables is too congested with six arms, as well as introducing some grounding issues. So, as I told pindac the other day, I started to experiment with using two pods per tonearm. Not just a simple 'if one is good then two must be better' but for practical reasons. Firstly, a pod resting on three spikes weighs about 10lb, but it doesn't take much pressure on the distal end of the arm panel to cause it to tip. One can spoil a carefully set up alignment that way, and if it continues tipping a disaster could happen. So, I thought, why not place a pod under the distal end of the tonearm panel, and prevent that happening?

But then a second thought came along: if the second pod were firmly coupled to the panel, I would double mass and damp vibrations even more. That's a bit theoretical to me, as my oak chest weighs ~350lb and I can stamp on the floor next to it and not disturb a playing stylus. But rigidity is rigidity. So I asked Lee if he could make me a double ended panel with an SME mount centred in the middle. Roughly, like this:

He agreed, and pointed out I would have to forego the VTA adjustment, unless one were to place a screw at each end! I can use the SME mount itself to adjust VTA. though, so that's OK.

Here, finally is the question: he thinks I am simply introducing twice as many vibrations (external, I think he means) into the tonearm by having it rest in two sites on the oak chest, and that I would be better off having one end of the tonearm panel free-floating. My view is that rigidity is paramount, and if a built-in tonearm on a table is firmly coupled to the table then I am moving a bit closer to that ideal by having a firmly coupled chest-table-pod system. What say you?

dogberry

@pindac The artificially applied kinetic energy is just a very rough indicator. @dogberry relates that thumps make it through with his Soundsmith which means that low frequencies are being transferred to the stylus of every cartridge, but one can ponder why he hears it most with the Soundsmith. What you are referring to as "natural kinetic energy" I call environmental rumble. You have subwoofers. If you can see the drivers, place your stylus down on a stationary record and turn off any low frequency limiting filters. Turn the volume all the way up watching the subwoofer cones. Now you can see environmental rumble which occurs at very low frequencies. Many suspensions, even the lowly LP12 are capable of isolation the cartridge from environmental rumble. Hanging suspensions such as the Sota, Basis, SME and Oracle are the best at it as are the MinusK and Vibraplane platforms. I can not speak for any others. To work a suspension has to have a resonance point below the frequency of the rumble, below 3 Hz is optimal. Done correctly an isolating suspension will also protect from foot falls. Done poorly a suspension can make footfall problems worse, the LP12 being a great example. 

Dear @dogberry : Not polite but anyway: you already did it but are wrong with those 2/separated Pods, no matters what.

and enjoy the MUSIC NOT DISTORTIONS,

R.

As a fact tonearm/TT must be exactly in the same plane/plytnh, external arm pods looks fine and sometimes we use it by necessity but is totally wrong.

@lewm can explain why/it.

 

Regards  and enjoy the MUSIC NOT DISTORTIONS,

R.

@dogberry Everything about the replay of Vinyl is with fault, but the very worst of the wrongs for the replaying of  music using Vinyl, is quite capable of a replay to a level that can be enjoyed.

Then there are those that work that much harder to eek the incremental changes towards what is referred to as a improvement, which is certainly not an improvement in the enjoyment.

My most enjoyable times remembered around, Music, Photography, Fishing, Driving and some other interests, were when I new the least and had the worst tools or experience to get the job done.

There is not an explanation to be offered to convince that music will be more enjoyed as the outcome.

There is an explanation that can be offered to assist with understanding what is a optimum parameter to be aimed for, in relation to the setting up of each interface that is a necessity.