VTA and HTA overhang

Theo, adjusting for differences in record thickness (weight) is exactly what I do using a Herbie's "Donut" mat. I use a 0.5mm mat to compensate for the thinner 120g-150g LPs. Actually, I'm compensating for the heavy 180g-200g LPs that I started purchasing a few years back; I noticed that SRA was changing slightly with the thicker LPs. So now I set up my cartridge alignment and tonearm height for proper SRA using one of my best 180g LPs (even thickness and flat) and then use the "Donut" mat to raise the thinner LPs up off the platter. It's not an elegant solution like the VTA adjusters on some tonearms, but it works.

The 0.5mm mat was a compromise because it actually works for a small range of LP thicknesses. (Refer to chart below.) I tried using a 0.8mm mat for the thinnest LPs (100g-120g) and used the 0.5mm mat for 130g-150g LPs but found that dealing with two mats wasn't worth the additional benefit for the lightweight LPs. They comprise a minority of my LPs so I can live with it. I'd rather set things up to optimize for the majority of my records and the high quality heavy vinyl.

Thickness/Weight
1.00" / 100g
1.27" / 120g
1.52" / 150g
1.77" / 180g
2.02" / 200g

I found the "Donut" to be sonically neutral using it with a Gyro SE platter. I'm not sure about other platter materials and construction.

Regards,
Tom

Tom
Thanks, I didn't realize the "donut" excisted. And i gatehr from what you are stating that you have found it to have no effect on sonics? I wonder how it would perfom on a suspended table like my LP12. I guess I should research this as an option.

Fleib, I'm not sure where I wrote that SRA does not matter. I don't feel that HTA is necessarily more important than SRA. It's all important and all we can do is optimize all the dimensions the best we can. I also do not think that small adjustment of VTA without resetting HTA is wrong. I was just pointing out its effect on HTA.

As for Stevenson or Baerwald you gotta go with what sounds best to you.

I just looked at the vinyl engine calculator again and it shows Baerwald as having the least max distortion and Lofgren B as having the most max distortion. Lofgren B has the least average distortion though. Baerwald has less max and average distortion than Stevenson so I can understand why it is popular.

Theo, The Herbies Way Exellent II Mat is what I think Tom is referring to. I have one and have used it on a LP12. They are fairly light and work well on the Linn. They do make them in many different heights.

On my current TT I prefer a harder mat though.

I view perfect alignment if the stylus touches the inscribed arc at any point on the Mint protractor