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Upper Level Vintage DD Strenghts and Weaknesses

All of these tables have been discussed in some form or another here over the years. I have read quite a few threads on them, but its a bit difficult to nail this point down.

Basically I am looking for a non-suspended table to install a Dynavector DV505 arm on, and these tables can fit the bill.

The most widely available is a Denon DP 75 or DP 80 in a Denon plinth, and they are perhaps the most affordable also. Are there any of their plinths that are desirable, or are they just a veneered stack of MDF or plywood?

While more expensive I can find a Sony TTS8000 in a Resinamic plinth although shipping from HK is expensive. There is one thread I came across here where a member who restores tables says two of the three TTS8000 he has done had play in the spindle assembly which looked to be wear in the brass bushings of the motor. That does make me pause in concern.

The JVC TT101 is not only difficult to find, its apparently a bit of a bear to get serviced, so its not high on the list.

The Technics SP 10 MK II I have owned, and its a nice table but to be honest I had a Denon DP75 that I felt actually sounded better. Also the models that are out there are either abused or have a premium price tag attached to them. Also I don’t need instant torque, and I think the bi-servo designs might offer better speed control.

As I write this the Denon and Sony seem to be at the top of the list, unless there is another I should be looking at.
neonknight
neonknight OP
399 posts
 
@lewm 
This is from the manual on the DV505. 

Horizontal balancing

Main arm is designed to maintain itself always level. But horizontal balancing is still necessary to distribute bearing load evenly and thereby realize best trackability. To achieve this balance, shell and sub weight alone normally suffice. First position sub weight A closest to the fore, or sub weight B at white-color balancing point mark, and then slide sub weight on scaled bar by one notch backward per every 5g added to cartridge weight. (In using any shell other than one supplied, add to or deduct from cartridge weight the difference in weight between these two shells.)



It's a bit confusing, but it essentially references how to set the counterweight on the main arm wand. It does have to be set, and you will see some travel on the primary arm wand in the vertical plane, but it's very limited. If a bearing was not there then why would you have adjustment of that large counterweight? 
lewm
13,313 posts
 
The subweight is moveable fore and aft to balance the mass directly over the center of horizontal rotation. It is an approximate exercise, at best. But the actual horizontal bearing will only rotate in the horizontal plane. It’s true that you can tilt the whole shebang backward by about 30 degrees for various adjustments, but in operation the anterior vertical bearing will do all the work in the vertical plane. Its friction and mass are very much lower than what needs to be overcome if you tilt the whole assembly rearward on the posterior horizontal bearing. Unfortunately semantics get in the way of conveying my meaning as clearly as I would like. Photos would be better, if I knew how to post them.
neonknight OP
399 posts
 
@lewm 

No worries, I know exactly what you mean since I have set the arm up. It's interesting how the primary arm counterweight loads the horizontal bearing. I guess that degree of travel is a function of the horizontal bearings architecture. It makes sense that this bearing needs to be loaded so it's arc is flat in the horizontal plane, and the magnet assembly ensures that also. 

The Dynavector sure represents some unusual design decisions. But from what I hear it works very well, provides you have an unsuspended table. I guess the new generation Graham, Reed, Triplanar, and whatnot are supposed to be superior, but I have a suspicion it's not by a huge margin. I like what I hear from this arm with the cartridges I use. 
dover
2,262 posts
 
@neonknight 
Hi - the way to think about settng the main counterweight on the Dynavector arms is to think of a tightrope walker with a pole.
The purpose of adjusting this counterweight is to provide perfect balance over the top of the horizontal bearing with the chosen cartridge/headshell installed.

Because of the course markings on the counterweight positioning scale on the arm beam, I ignore them. Here is my recommended procedure -

I weigh the cartridge/headshell
Install the cartridge, align and set the tracking weight to zero.
Then I position the main counterweight roughly in position according to the scale on the beam.

Additionally, and this is most important, I then fine tune the exact position the counterweight by blowing on the arm ( sideways ). When perfect balance is achieved the arm will sway back and forth with just a puff of wind.

For the purpose of this last step I remove the platter so the arm can swing in and out without worrying about wiping out the cartridge.

Last time I set up my Dynavector, I stopped to have a coffee after performing this step. Whilst sitting off to the side, I noticed the arm was moving back and forth in the breeze coming in a side window. Its pretty impressive when you see it - it sums up how the split biaxial system is actually designed to work.
neonknight OP
399 posts
 
@dover 

Thanks for the description of your procedure, it sounds like pretty conventional set up technics for a standard arm, but they serve a different purpose with the Dynavector. Balancing the primary arm wand on the horizontal bearing makes a lot of sense, and I can see the usefulness of the technique. I will give it a go this weekend, and see if I can tease a bit more performance out of the table. The Dynavector is an excellent arm, it kind of surprises me that its become a forgotten choice for many in the analog world. Of course the latest DV507 is not a cheap arm by any stretch of the imaination, so that will limit its audience. I will say i am in awe of its level of engineering, especially considering its now a vintage arm that supposedly is dated due to its design and materials. Although from what I hear I would not describe it as such. 
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