setting VTF with a digital guage

Andy, you might try experimenting by measuring the differences in VTF between the gauge and your setup LP to develop a calibration adjustment that you can apply when using the Acoustech gauge on the platter.

Start by figuring out how much higher above the platter the gauge surface is than the LP you're using to set VTF. You could set the gauge on a flat surface and place an LP (or LPs) next to it until the heights are the same. For reference, here are the measurements I've compiled from some posts I've read...

Hgt(mm)-Wgt(g)
1.00 - 100
1.27 - 120
1.52 - 150
1.77 - 180
2.02 - 200

Then, with the gauge on the platter, set your tonearm and cartridge combination to 2.00g of VTF.

Without adjusting the counterweight, place the LP(s) on the platter equal to the height difference you measured and record (and average) the VTF.

You now have the difference in VTF readings between the gauge sitting on the platter surface and your setup LP.

You'll then have a calibration factor that you can apply to the VTF measurements you get with the gauge on the platter. For example, if the VTF difference you recorded was 0.1g higher (the readings averaged 2.1g) you actually set VTF 0.1g lower to get the VTF you're after.

If you're really motivated, you could record measurements for a few different thicknesses to see if the relationship is linear or curvilinear, but I'm not sure that's necessary.

You can protect the surfaces of the albums by using thin sheets of paper.

Regards,
Tom

Despite my suggestion to develop a calibration factor for the Acoustech, I didn't go to that much trouble to set VTF. Close enough was good enough.

I had (and liked) the Acoustech digital gauge but it failed on me. I went back to using a Shure gauge and it works OK, but I missed the convenience and accuracy of a digital gauge. I bought one that was built like a tank (unlike the more delicate "analog" ready gauges with the thin platforms) and made a platform extension out of a credit card that was the same height as my setup LP. Works great; easy to use and reliable.

For Kiddman: Although not precisely consistent, there's a relationship between record weight and record height (thickness). I use a thick 180g LP as a reference to set up a cartridge and use a 0.5 mm Herbie's Donut platter mat to partially compensate for 120-150g LPs to keep the SRA within a relatively optimal range. I also bought a 0.8 mm Donut mat for very thin LPs (Dyna-Flex) but most often just use the 0.5 mm mat. For 160g LPs I either use the mat or use a bare platter depending on the mastering.

It sounds complicated but it's not. I can flip the Donut mat onto the platter or remove it in a matter of seconds. And it does make enough of an improvement to be worth the cost and effort, though I probably wouldn't bother buying the 0.8 mm mat.

Regards,
Tom