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

Showing 2 responses by dougdeacon

Why not just make a weighing step with enough drop-down to put the stylus at record height when the scale & step are sitting on the platter? Let's you measure at the right height and, if you make it the right weight, it will put your scale near it's midpoint of weighing capacity, which is where load cells are most accurate. I made one by folding a piece of copper strip. Cost me $0.50 from a hobby shop and 2 minutes of time.

Beyond all that, adjust your VTF by listening, not by what some scale says. Scales only get you in the ballpark. Your ears will tell you when it's right. Changes smaller than .01g are audible on my rig so a scale's useless anyway. The only time mine comes out is when I'm changing cartridges.

There is no "magic" SRA that can be pre-set. Every LP was cut at a different angle. Unless you know that angle (nobody does) the only way to set it is by listening.

Azimuth is important and in theory there IS one perfect setting. I set it by ear also but a measuring device like the Foz is also valid. Diffence between channel output level is not what you should be measuring however, azimuth doesn't affect that. What you should be measuring (and striving to reduce/balance) is crosstalk.

The sonic effects you described are much more likely affected by VTF than by SRA or azimuth. Spend a LOT of time playing with SMALL changes in VTF. Try this exercise:

- set A/S to zero
- choose a passage that's difficult-to-track cleanly (hard hit piano, solo horn, solo soprano... especially on inner grooves)
- play, reduce VTF by .05g, play again
- repeat until you hear mistracking (actual breakup, fuzziness, faint crackling... with A/S at zero you may hear it in the R channel first)
- increase VTF by .01g and play again
- repeat until the mistracking sounds diminish or disappear
- continue replaying adding.01g to VTF each time and listen for two things: speed, pace,HF clarity and low level detail vs. weight and punchiness of bass
- the cart will have a VTF window where these two opposites are optimized, that's where you should play it; the window may be wide or narrow (on my ZYX UNIverse it's exquisitely narrow, actually less than .01g wide)
- the window will move(probably lower) as the cart ages and will fluctuate with the weather and other factors; I've had my window move by .015g just because I stopped for dinnner for two hours, giving the cart a chance to cool down a bit.

Err... have fun!

P. S. If JC weighs in believe him, not me. :)

...to go from mistracking to "singing" with tiny tweaks just doesn't sound right."
I've no experience with the Kleos, 20X2 or Zephyr, but I assure you that with many cartridges the difference between mistracking and singing is indeed just a tweak or two away. Many cartridges (though certainly not all) play best quite close to their mistracking point. The way to optimize such cartridges is to find that point and tweak from there. Not sure why that "doesn't sound right" where you are, but I assure you it sounds just fine here! ;)