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
I have the classic 3 and use the VTA tower to get the correct height for VTF calibration. Set VTA tower for the record. For my electronic scale 5 revolutions on the VTA Tower CCW increasing pivot height results in same geometry with my scale as the record. I use a very accurate ruler to determine that I needed the 5 revolutions. Just to give you an idea. If I set my VTF using my scale on the platter without adding those 5 revolutions then a 1.95 gram setting will really be 1.78 grams on the record. Just figure the difference in height between your record and scale in terms of VTA tower rotations and you are set.
I use a MyWeigh digial scale that's nearly half an inch thick. To set VTF at the record surface, I made a little jig by hacksawing a 2-in. and a 5-in. piece from a plastic ruler, drilling a hole at one end of each piece, and connecting them in an L-shape with the shorter piece standing off from the longer piece by the thickness of the scale. It's easy to do with a nylon bolt, washers, and nuts. I used plastic and nylon because they're light and free from any magnetic interaction with the cartridge. The jig is rigid and adjustable and only costs a buck or two. Then just place it on the scale so the short piece of the L hangs off the record at its level; place a counterweight atop the other end to keep it from lifting off the scale when the cartridge is lowered; tare its weight to zero; and drop the needle onto the little plastic platform.
...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! ;)

Make a weighing step as Doug suggested.
I made one similar to Wally Malewicz's with a small plastic ruler and a nylon bolt/nuts so that it can be finely adjusted. Others have used a piece of folded credit card.
Wallyscale copy

I'd be surprised if your VTF was anywhere close if you're using a scale on top of the platter. With my previous Graham 1.5T I could get changes of tenths of a gram when adjusting VTF! This is a known issue with stable balance unipivots.
I previously owned the Kleos and still have the Atlas and the Titan i. I am no expert but I hope to share my experience. If your results differ, we can learn together. There are many different strategies amoung audiogoners so try to see what get you the best sound.

From my experience with the Kleos using various arms (unipivot and gimbal bearing), some degree of antiskate is needed to bring out the best in the Kleos. The optimal VTF setting is within the factory recommend VTF using some antiskate. If I set VTF without any antiskate, I would arrive at slightly heavier VTF to counter the problems with missing tracking. This would result in suboptimal alignment of the coil and reduce the maximal performance achievable. The primary purpose of proper VTF is to alignment the coil precisely. Remember that changing the VTA setting will change the VTF and changing the VTF will modify the SRA with the same VTA setting. Proper SRA reduce distortion and VTA is the dial that you use to adjust SRA. In a sense, it is like solving a equation with two varibles that are interdependent. A good way to start is keep VTF constant, say 1.8g at record level, then change VTA up and down to find the proper SRA. As you are changing VTA, you will need to confirm VTF and may need to adjust counterweight to keep VTF constant at 1.8g. After that, repeat the same exercise with VTF at 1.75g, 1.7g etc. see what setting you ultimately prefer. This would land you a VTF that is slightly higher than optimal if antiskate is not compensated for.

Next set antiskate so both channels are tracking equally well. If listening to orchestra, the violon section should be playing as well as the cello/heavy strings section. If too little antiskate, the heavier strings lose focus and you cannot hear the sublties in play style, the boundary interactions within the acoustic space. If too much antiskate, the damage would be done to the violin sections. If you listen to vocals, the voice would be pulled left if too little antiskate and pulled to the right if too much antiskate. The centering of the voice is also affected by proper azimuth setting which is a potential pitfall. Best to listen for other clues like boundary interactions within the recording. In vocals, if the singer is centered, the boundary interaction of her voice should be apparent on both sides. If antiksate is off by large amount, tracking distortion would obscure the spatial clues present in the recording in the particular channel. Another way is to use a very difficult to track musical passage and having mistracking happen at both channels at the same time.

My understanding of skating force is limited but I know that it varies along the record surface. Tends to be least on the outside and most at the inside. However, it does not increase linearly towards center. It is modified by friction betw stylus and groove ( which is dependent upon speed of the rotation, shape of contact point of the stylus, VTF) and tracking error. Someone worked out a formula at vinyl engine if you are interested. A happy compromise is key here.

With the antiskate set, repeat the exercise with the VTF and VTA. Hopefully this yield the best sound.

Using fozgometer is OK but I feel this is a rather expensive device for its limited function. A PAA3 spectral analyzer can measure crosstalk more precisely and have many other useful functions. The lyra carts generally have great quality control, probably best I have had. My Kleos had better than 30db separation in both channels. The maximal channel separation you can achieve can be impaired by poor alignment. In the unipivots that I have tried: graham and centroid; the antiskate also modified the optimal azimuth setting slightly. Proper antiskate maximize channel separation.

As you alread know, the actual VTF tends to be lower than the VTF measured with the meter on the platter. I put a record on the platter and put the meter on a stack of cd/cd cases so the meter is leveled with record surface. Do your measurement there for a closer approximation. ( The actual VTF will be varying across the record surface as the record increase in thickness towards the center).

There are so many compromises one need to make during setup. I am amazed that vinyl stills sound better than digital for me.

good luck