How important is Cartridge Overhang? Need help

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

Hi, Wilson667: A difference of only 1.0mm should not prohibit you from adjusting the position of the cartridge in the 9cc tone arm headshell to align to the Lofgren A/Baerwald geometry. The headshell slots have enough play forward and backward from the middle position, which accomodates most cartridges with typical mounting hole to stylus distances of +/- 9.5mm, to easily accomodate your HMC 20.

Something doesn't sound right. Before spending money on another cartridge, try using the Conrad Hoffman protractor, which works very well for the Pro-Ject tone arms. Download from the link, unzip, print, and follow directions in the README file.

http://www.conradhoffman.com/TemplateGen.zip

Tom

Dan_ed; I would also consider that the Mink protractor may not be constructed correctly. If the wrong parameters were given or used to set the markings on the protractor that could also account for the problem trying to use it with the Pro-Ject 9cc tone arm. There should be more than enough play in the headshell slots to accomodate a 1.0mm difference in cartridge mounting hole to stylus tip distance. Unless Pro-Ject has recently redesigned the 9 series tone arms, a typical cartridge with 9.5mm mounting holes to stylus tip distance puts the cartridge right in the middle of the slots with almost 3mm of travel fore and aft.

That's why I asked what dimensions were used to create the Mink protractor: Are they the correct dimensions? Using parameters of 212mm spindle-to-pivot distance and a 230mm effective length the cartridge should easily align to a Lofgren A/Baerwald geometry with the Pro-Ject 'arm. And also why I suggested using another protractor with the correct parameters to compare with the Mink protractor. Conrad Hoffman's TemplateGen is a quick way to check. That would indicate if it's the Pro-Ject turntable or the Mink protractor that was possibly mismanufactured.

Until more information is provided all bets are off as to what is causing the problem.

Tom

Hi, Wilson667; hopefully things all work out with your Mint protractor. What is the distance from the vertical tone arm pivot to the center of the headshell slots? You should get something around 220-221mm if the effective length is correct at 230mm. (220.5mm + 9.5mm holes-to-stylus = 230mm)

I measured the distance on my Pro-Ject 9 aluminum 'arm and the center of the headshell slots is just over 220mm from the pivot, which is correct for a typical 9.5mm mounting hole-to-stylus distance. It could easily accomodate the 8.5mm distance of the HMC-20.

Tom

Hi, Swampwalker; pivot to stylus distance is not really variable with the Pro-Ject 9 series tone arms. The headshell was designed such that installing a cartridge with typical mounting holes will put the holes at about the midpoint of the headshell slots and the stylus at the designed 230mm effective length. The slotted headshell allows for a range (~6mm) of cartridge mounting hole configurations but there is only one correct effective length for the intended alignment geometry.

If the distance from the pivot to the center of the headshell slots (~220.5mm) is grossly different for the OP's Pro-Ject 9cc tonearm, then the stated 230mm effective length may be in error. As to whether the pivot-to-spindle distance is grossly different than the stated 212mm, it's an easy task to measure that distance on the Pro-Ject 'arm. I get ~212mm with an aluminum 9 tonearm installed on a (Pro-Ject) mmf-7 turntable.

If Wilson667 takes a few quick measurements it may eliminate a couple of the obvious variables.

Tom

Hi, Wilson667, have been gone this weekend or would have responded earlier. Sounds as if the tone arm MAY have been redesigned and the specifications have not been revised to reflect a different effective length of (perhaps) ~237.5mm. That's assuming that Pro-Ject still designs the headshell for a range of cartridge mounting holes-to-stylus distances. If the center of the slots is at 228mm plus ~9.5mm gives an effective tone arm length of ~237.5mm. The other assumptions are that the headshell offset angle has been revised to accomodate the Lofgren A/Baerwald alignment geometry and that Pro-Ject may have unfortunately failed to change the pivot-to-spindle distance to ~220mm to accomodate the revised effective length.

So many variables and so many assumptions. Not a good scenario.

My advice is for you, or the retailer that sold you the turntable, to contact Pro-Ject/Sumiko USA and ask about the apparent discrepancies.

Tom