How important is Cartridge Overhang? Need help


Just received a Mint protractor for my Pro-ject 2 Xperience. I started the processes of setting the Overhang and it seems that my Ortofon HMC 20 can't achieve the proper overhang. The cartridge is maxed out to the front of the head shell and the result I get is: at the outside of the arc it sits perfectly and on the inside it sits behind the arc. I guess my question is this how important is overhang and if it is important is there a good compromise.Should I just get as close as I can and worry more about alignment?
128x128wilson667
Hi, Wilson667; the first question (just to be sure) is what are the spindle-to-pivot and effective length distances that your Mint protractor is designed to accomodate? The second question is what is the distance (measured as best you can) from the mounting holes in the cartridge to the stylus tip?

If the Mint protractor is designed for a spindle-to-pivot distance of 212mm and an effective length of 230mm then it's a match for the 9cc arm that comes with the Experience 2. (Sorry if you know that already; just helps to troubleshoot if all the information is available.)

As for the Ortofon HMC20, if the distance from the mounting holes to the stylus is about 6mm or more you should be able to set overhang correctly. That's assuming the 9cc has slots in the headshell the same as the headshell on a 9 aluminum arm. If the mounting hole to stylus distance is less than 6mm it may require you to use a different protractor and a different alignment geometry. Between the handy alignment geometry calculators available at VinylEngine and the TemplateGen (custom) protractor available from Conrad Hoffman you'll find something that could work very well.

Tom
Maybe I'm missing something. It is hard to get the picture without seeing it.

I'll assume you have followed others advice and have verified the P2S.

You say that the cart is all the way forward, it hits the arc on the outside but sits behind the arc on the inside. And that the cartridge is all the way forward in the slots.

So, if you move the Mint protractor back until the stylus is on the arc at the inside, will the cart not be too far forward on the outside now? Which is ok, because you can move the cart back in its slots.

Of course after you move the cart back, you will now need to move the protractor again to align the inside and then recheck the outside again. Keep doing this, correctly, and you should find that everything is converging on the arc. Using an arc protractor is an iterative process. I think you just need some practice.

Perhaps it will be easier to start with the cart in the middle of the slots?
The only point to overhang and pivot to spindle distance and offset and such is to help you get a starting point to better align the stylus to the appropriate null points on the curve (Lofgren or Baerwald and such). That's the purpose of these things. If you don't take the pain to set them exactly, but still manage to somehow align the stylus appropriately, I will bet that you have inadvertantly gotten them very close to where they should be.

But why take that chance and make it more difficult for yourself? Set it right the first time, then listen to music.
Dan_ed wrote:You say that the cart is all the way forward, it hits the arc on the outside but sits behind the arc on the inside. And that the cartridge is all the way forward in the slots.
From the setup instructions I've been able to see online for arc protractors, the condition the OP described does indeed indicate that there is not enough overhang adjustment possible. http://db.audioasylum.com/cgi/m.mpl?forum=vinyl&n=738382

It's always possible that his Mint protractor was mis-manufactured or that his turntable doesn't exactly match published specifications for arm length, pivot to spindle distance, etc. I agree with others that trying a different protractor is the best first step. If he doesn't have enough overhang for Baerwald alignment, maybe a Stevenson protractor will work. Two-point protractors and single-point, line of sight protractors (such as the Geo-Disc) can work with a variety of turntables and arms as they are not "tailor-made for a particular turntable tonearm setup"; even the best tailors can make a mistake.
That write up from John assumes the arc is in the correct position. You can't just flop down an arc on the table any where.

Again, very important, I'm assuming the arm is set to the correct P2S.

Look at John's drawing, keep in mind the cartridge is all the way forward. From the OP's description it seems that the cartridge is hitting point C. However, the cart is already too far forward.

Now move the arc back until the stylus at point C is on the line. Where did the stylus move to in relation to the arc on the outside? Does it not end up to the left of the arc?