Graham Phantom DV XV-1s setup question

Musichead,

Good discussion. What you heard as you tweaked VTF (balance of highs vs. lows, altered dynamics) is exactly what I've been advocating for years based on my experience with other top level LOMCs:
1. Take VTF down to the mistracking point (on real records).
2. Then nudge it back upwards in TINY increments whilst listening for exactly what you described. With practice, you'll eventually hear differences from changes of .01g or even less.

Of course this ideal VTF point will vary with break-in, with the weather and even from record to record. It's a moving target because the molecular characteristics of elastomers are unstable by nature. So I tweak our VTF daily, as do many on this forum, but I haven't had my scale out in weeks (the last time I changed cartridges). For daily listening I don't need to know a number. I just adjust by listening.

Question: why not trust your ears and listen at the VTF that sounds optimal, starting right now? You paid nearly $3K for a very fine cartridge. Why not enjoy its superb highs and dyanmics for every hour of its (limited) lifespan?

Doug

P.S. Excessive Antiskating has the same sonic effect as excessive VTF: dulled highs and smothered dynamics. Try setting A/S to zero before finding your optimal VTF. Once you've dialed VTF in really well, play some challenging tracks (real music, not test tracks) and listen for R channel mistracking (with your ears on the tweeter axis). If that occurs, nudge A/S upward until mistracking disappears or is even on both channels. Use too much and you'll hear the same sonic negatives as raising VTF. You'll probably end up using much less than most people think is needed.

Interesting points you make about the VTF continually changing and dependent on the record as they are not all cut the same. That logic explains what I hear, you either continually adjust or you accept a compromise on some.

Exactly.

BTW, I second Jazdoc's recommendation of the Mint if you don't already have one. Major improvement on my rig too, well worth the cost.

Regarding A/S I compared the minimum with the weight and no weight and preferred the sound with no A/S slightly more dynamic.

Exactly, again!

One problem with all A/S mechanisms is that they apply a force via a different vector than the skating force they purport to counteract.

Skating forces pull inward on the STYLUS and CANTILEVER. Anti-skating devices pull outward on the TONEARM. What mediates this imbalance of forces? The only compliant connection between them, i.e., the suspension inside the cartridge.

So, all A/S devices press the cantilever laterally against the elastic suspension (just as VTF does vertically). What happens when you pressure a vibrating rod against an elastic polymer? You dampen the vibrations, reduce their amplitudes and slur their transients. Sonic result: reduced dynamics, blurred transients and smothered HFs.

Skating forces exist, so some A/S may be required by some cartridges for clean tracking. But the less you can get away with the greater the dynamics and the faster the transients. Now all you need is downstream equipment good enough to reproduce these without distortion. It seems like you have that.

Agreed, and it's not just the XV-1S. This has been my experience with other high end LOMCs (Lyra Olympos, ZYX Atmos, ZYX Universe). For any particular LP on any particular day, optimal sonics are obtained by applying the least downforce and side force consistent with clean tracking.

One could imagine an MC built such that the downforce required to center the coils in the magnetic fields differed significantly from the downforce required for clean tracking. In such a case, optimizing sonic performance would be impossible. One would have to compromise between maximizing cantilever freedom or maximizing coil/field centering. That would be frustrating, as one optimizes speed, micro-dynamics and HF response whilst the other optimizes amplitudes and ensures the most accurate reproduction of waveforms. I suspect that many unbalanced sounding cartridges suffer from this ultimately insoluble flaw.

Good job ordering a Mint!

Dev,

First, do your line stage, amp and speakers produce acceptable SPL's and dynamics with line level sources at a reasonable gain setting on the line stage (i.e., somewhere between 10 and 2 o'clock)?

If so, then the phono stage gain you need for any cartridge can be calculated using the KAB Preamp Gain Calculator . Plugging in the 0.3mv output of an XV-1S indicates that 61db of phono gain would be suitable. Your VAC's 64db should be more than adequate.

Further, I've heard the VAC Renaissance (62db MC gain) in my system with both XV-1S and ZYX UNIverse (similar output). The gain was ample and the VAC was among the two or three best phono stages I've heard after my Doshi Alaap. It's a fine unit and an excellent match with that cartridge.

The VAC website indicates that phono gain is selectable (and also that the inputs labelled phono may optionally be just another set of line inputs). Make sure that you actually have a phono stage installed, ;-), and also that you're on the MC (64db) setting and not the MM (44db). I don't know where the switch is, check the manual.

Assuming everything's adjusted right, what did your setup guy hear that made him want more gain? From the information you posted it seems unlikely.

Myles,

That makes good sense for active demagging/fluxbusting, where the potentially conflicting requirements for music play don't exist.

1. The LP need not be spinning, there's no need to optimize VTF for clean tracking.
2. You're not playing a modulated groove, there's no need to optimize VTF for maximum cantilever freedom.

Maximizing the fluxbusting effect obviously requires that the coils be centered in the fields. Now tell us the precise VTF that centers the coils when the cantilever isn't moving - good luck! ;-)

Whether one should actively demag a cartridge at all is of course subject to debate. As I'm sure you know, active demagging would destroy any MM, any MI and some HOMCs. Whether a LOMC should be actively demagged depends on the cartridge. Many LOMC manufacturers advise against it and will void the owner's warranty if it's done. FWIW, I prefer the less dangerous "demagging" tracks on the Cardas LP.

Shocked to find out the Graham tools aren't 100% accurate.

Heh. I've never used the headshell jig when setting up Graham arms. Even before the Mint arrived on the scene I got superior results with on-platter protractors. The jig is quick, easy and idiot-proof, but given its self-evident limitations it was never particularly accurate.

Of course nothing is 100%, especially in vinyl, but the Mint gets us all orders of magnitude closer. Glad to hear you're enjoying fresh music!