Tonearms question - Please help

Never let your Denon go for a belt drive!!!
Measure the pivot to spindle distance and search for the proper effective length of the potential new arm.
ie: pivot=221.7 for eff. length=239
pivot=232.4 for eff. length=249
pivot=222 for eff. length=239.3
pivot=230 for eff. length=246.736
So, you can see if the pivot you allready have is close to 222 or closer to 230 and proceed to find a decent new arm for your Denon that matches the right eff. length.
Needless to say that you are going to loose more money if you consider to change both your defective arm & also your excellent table!!!
My advice is to give your best effort to support your turntable with integrity. Buy the best arm you can afford and don't worry for the proper height -you can use cork of different millimetres under your LP mat, or you can change the rubber mat for a graphite or a copper one in the future-, you may add some nice footers & a base platform, you can let a technician to upgrade the internal electronic components to the present technology ICs & capacitors and in the end you will never have to worry for the "new & improved" plastic belt-drives with their coin-like motors and the endless upgrade path.
Do whatever is possible just don't let it go...
George

I answered the original question but if it were me I think I would get a Rega 3 or used VPI as Chazzbo suggested. I also think belt drive is better, I have sold both. But if you like the Denon the Jelco should work, but it may require a good tech to fit it and they are not all that easy to find. The VPI is better [I am a VPI dealer] but the Rega is very good for the money and much cheaper. I think there is a NOS one for $600 listed now and used ones for less.

You guys are awesome! I really appreciate your input. Thanks and let me know if there is anything else.

That is the Jelco 750, which is a very good arm, I have one. However, the 250 arm is available in either straight or S version for $290.

Sure you want DD TT?Have you heard a decent Belt Drive to compare?Yeah you have potential of less peed acccuracy but with a decent belt drive you have less rumble and a new maybe better experience/For price of replacement arm.Ask movers for cost of replacement and check out a Rega,VPI or other deck that would equal price of arm more or less.Jelco 9" is nice but will set you back $500 or so.Just a thought.
Chazz

There are two key things you're concerned about.

One is the pivot to spindle distance - the distance from the center of the mounting hole to the record spindle. On the 250 style Jelco, it's 214 mm.

The other issue is whether your Denon's platter height is standard. A good working number is for the top of the platter to be about 1-3/8" (1.375") above the surface of the armboard.

Dealer disclaimer - I sell the Jelco arms under the Artisan Audio badge.

Cheers,
Thom @ Galibier

The Denon arms were not that good, I would check with the Audiogoner who sells Jelco, Audiodragon I think, who may know if they will fit easily. Any of them will be much better than the Denon. The first thing to do is to completely remove the old arm and see what size hole is left. Don't worry about doing this; I know from personal experience that taking things apart is far easier than reassembling them and you don't have to worry about that. Post what you find and I or someone else will help you farther.