Stylus Rake Angle


I am trying to set up my new VPI 3D arm as close to perfection as I can. On the Analog Planet, Michael Fremer gives one opinion, however, a different opinion was voiced by Harry at VPI, and Peter at Soundmith. I've been discussing this with them....Fremer says that SRA should be adjusted even if the back end of the arm is WAY high up as needed, whereas Harry, and Peter said to start with the arm in a horizontal position and move it slightly up and down to find the sweet spot. Peter said that my cartridge (Benz LPS) and some others have an additional facet in the diamond so bringing the arm up in back would be exaggerating the proper SRA. When I wrote back to Fremer, he answered with an insistance that he was correct. Does anyone want to add to the confusion??
128x128stringreen

Showing 1 response by don_c55

Whatever your starting point, level or 92 degrees, the actual SRA arm height range is very, very small! Adjust "on the fly" is worthless, because you will pass over this very narrow peak with a quick adjustment. You must "zero in" over time, to find the optimal spot, and reset azimuth and VTF as you go. Note sonic changes throughout this process, as it is a learning experience.

On my VPI JMW 10 the final sweet spot "window" is plus or minus one index mark on the Micrometer head height tower. This is a range of +/- 3 10,000 of an inch!
Without a micrometer head on your arm, I doubt you will find this optimal SRA spot.

Once I find this "sweet spot point" after listening to many Lp's, over a few weeks or months (after break-in is complete), I do not change the height. 95% of my records are of "normal" thickness, so I do not readjust height for the 180 gm Lp's.

I find I get super playback quality on 80% of my Lp's with this one setting.

One must also take into account recording quality variation, as some Lp's just sound "off" regardless of SRA setting. The resolution of ones system must also be acknowledged for your personal results. Adjusting for each Lp is too "anal retentive" for me!