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Lyra Kleos: tracking force/VTA/azimuth questions

I just bought a Lyra Kleos and I'm mounting it on a VPI JMW 12.7 (HRX turntable). I've done a bit of research, including Jonathan Carr's many posts here), so I know VTF is critical. I've done a trial set up to Lyra specs, and it doesn't sound right - piano in particular is distorted as if the cartridge is approaching break-up. I suspect the way I've set VTF. VPI recommends measuring VTF at the level of the record, which is impossible with the electronic scale I currently use - I simply put it on the platter and took readings, after first calibrating the scale, of course, and left it at 1.75 g. VPI says that simply measuring tracking force that way will under-represent actual VTF at the level of the record by a substantial amount because of the height of the gauge over the platter. Could that be the source of the problem I'm hearing? With other carts, I've done a couple of tests that seem to verify VPI's advice, so I plan to carefully measure the plinth to platter-top height, remove the platter, and build a temporary platform lower by exactly the thickness of the scale's pan. I'll put the scale on that, and then set VTF to Lyra's specs. This will result in VTF at the level of the record measuring correctly, when I put the scale on the mock-up platter, but NOT when I just slap the scale on the platter - it will measure higher. So my question is: does anyone see any potential problems flowing from my use of this process? I plan first to set VTA slightly tail high to approximate the magic 92 degrees SRA that seems to be the consensus of opinion these days.

Also, I'd like a bit of advice on using a fozgometer to measure azimuth. In my trial set up, I've never been able to get exactly the same readings left vs. right channel with the Foz; the best is a two-division difference, right higher in level than the left. I also get a one division reading, rather than zero, on the channel balance test, with both channel lights very faintly lit. Could this be a function of insufficient tracking force, or is there something else at play?

Thanks to any and all who might feel the spirit to respond (hopefully including you, Mr. Carr).
zachteich
stops
56 posts
 
I noticed while doing the measurement using the analogue test record that I was picking up surface noise that threw the measurement. I estimated this by getting a reading between the test tracks. Ideally you should subtract this from your minimum reading.This will much improve the separation of course.

I did however have to shim my cartridge (Benz Glider SM) to get both readings in the un-driven channel lower and reasonably matched. My Rega arm has no azimuth adjustment but I have added a VTA adjustment to it.

The improvement I got was quite staggering. I had thought I was already there....
Hope this helps.
bpwalsh
1,197 posts
 
Dinster, the Fosgometer measures channel levels and crosstalk. The Feickert software also measures phase, and adjusting azimuth to achieve minimum phase error correlates much better with what we hear.
pojuojuo
92 posts
 
Fozgometer measurements are channel separation and balance while Adjust+ software crosstalk phase. I prefer the first one because the signal goes directly from the cartridge avoiding the phono preamp. Don't forget all phono preamps add crosstalk phase to the final measurement.
yeti42's avatar
yeti42
287 posts
 
With a centre of gravity below and forward of the pivot point the force measured at the stylus will increase as you raise the front of the arm. Optimising my cartridge tracking force on my unipivot by ear if I weight the result on my electronic balance I get 2.42g but in my old Rega arm it use to run at 1.95g
hiendmuse
257 posts
 
Zachteich, I have a VPI Super Scoutmaster with 10.5i tonearm and Lyra Titan-i cartridge. I had been using the $80 made in China scales marketed as a cartridge scale, and then tried an Ortofon scale, which I sent back as it was not very accurate and only goes to tenths of a gram. I bit the bullet and paid $399 for the Cartridge Man digital scale and found that the 1.72 gram tracking force I thought I had when using the $80 scale was actually around 1.65 grams. The Cartridge Man scale is the thickness of a 200 gram record. I readjusted the VTF to 1.75 grams and the difference and improvement in musical performance was not subtle.
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