Home Vinyl Asylum

Welcome Licorice Pizza (LP) lovers! Setup guides and Vinyl FAQ.

RE: Anti-skate help needed please!

In general, if there are any issues with a Soundsmith rebuilt or new cartridge, we are here to help. There is some major misinformation in some of the below posts, but hopefully this will help.

Skating force is NOT caused by centripetal force. It is caused by the fact that the cartridge is mounted at an angle with respect to the arm tube (please note that most arms have the head shell at an angle). This is done to allow best OVERHANG position in terms of ZENITH (rotation of the cartridge clockwise as viewed from the top). This alignment (there are several - which have different advantages) allows "best" compromise for a pivoting or radial tracking arm. BUT - it creates skating force. Why??

Imagine a gate when you pull on the free end of the gate. The force pulls on the hinges, and the gate assumes a straight line between you and the hinge. NOW, imagine a huge, curved gate, curving to the left, with the hinges on the far end. If you pull on the free end of the gate, as if the hinge is straight ahead of you, (which it is not - it is off to the far left of you) - The gate will swing LEFT - this is because the force wants to line up in the direction you are pulling - it wants to line up with the hinge. The gate will therefore swing left until you are pulling directly at the hinge. Same with a tone arm. The "stiction" of the stylus in the groove pulls the tone arm; and at varying amounts to complicate matters! Lots of loud passages?? More groove modulation, MORE STICTION. Center of the record?? Groove modulations are TWICE as close together for the same frequencies (as half the vinyl is flying by), so MORE STICTION.

So - More skating force both when loud passages come, and more at the end of the record. So....antiskating is needed. How much?? Good question. Since stiction and the resultant skating forces are a moving target, there is no “perfect” amount of instantaneous Antiskating force that can be applied....HOWEVER....Frank Schroeder came up with a method AND AMOUNT of Anti-skating to use that does NOT require instrumentation OR a test record, and I could not agree more with this method. It DOES fly in the face of test records, but most everyone I have suggested it to has agreed that the sound is better. But it also serves to equalize record and stylus WEAR on each groove wall as well. We suggest LESS force than test records suggest. Why?? Because music spends MOST of its time at about 30-40% modulation levels. So why would one adjust anti-skating for only MAXIMUM recording levels?? That would mean that 80-90% there would be uneven force on the groove walls as a result of too much anti-skating force. Better to be correct MOST of the time. How do you do this??

Frank suggests that at the end of the record, you place the stylus on the TOP of the surface, where it will rest for a moment before popping into the run-out or end groove. Adjust the Anti-skating so the stylus stays put, OR drifts slowly in (Franks preference).

With the VPI, this is hard – but Soundsmith is producing a new antiskating device soon (called Vivenda) whose adjustment follows the tone arm and has no string – (thus allowing the arm to be removed quickly, and multiple arms to be used easily as the setting follows EACH ARM).

But how to set the VPI’s in the meantime?? VPI’s suggestion to twist the wire is too gross (in my opinion) and the use of the VPI antiskating device is a great solution - if you have one. Here is what we have suggested with our Soundsmith alignment guide Version 4.11
Which includes the following on how to set it with the VPI device, or with our Vivenda:
*****************

ANTI-SKATING AND VPI IMPORTANT ISSUES:

Some of us who own VPI tables are aware that in the past, VPI’s suggestion was to twist the signal cable one way or the other to affect a proper antiskating force. I have found that this is a fairly gross method, which does not allow for fine adjustment. VPI is now providing an anti-skating device, however, our new Vivenda Soundsmith Anti-skating device allows far easier adjustment, as well as allowing the arm to once again be easily removed, a feature that is well worth having. The other advantage is that the adjustment for antiskating now FOLLOWS the tone arm, so that multiple arms can again be easily used without having to adjust the antiskating for each arm each time. With the VPI supplied string type antiskating device, one must appreciate that its use does take some time to get right, as one is working against not only the skating force for the cartridge itself, but the side force from the stiffness of the signal cable as well. I have had some luck using the VPI anti-skating device by adding small brass washers (if needed), sometimes between 3 and 5 of them, to the far small arm that does not have the nylon string attached. I positioned them between the rubber o-rings that they supply to hold them in place and at the proper height – and it allowed me to adjust the force to exactly what was needed. Patience is often required.

The way to start with the VPI arms with EITHER anti-skating device is to FIRST INSTALL either type of device, but if using the string type VPI device - DO NOT HOOK UP THE NYLON WIRE FROM THE ARM TO THE ANTISKATING DEVICE. Then, PLUG IN the tone arm wire WITHOUT twisting it. If the tone arm skates INWARDS as described above in the antiskating directions, then you are OK. If it moves OUTWARDS, you must unplug and twist the ARM CABLE WIRE, (PLUG IT BACK IN EACH TIME) till the stylus tracks INWARDS AT ANY SPEED on the RECORD surface near the end lead out groove.

What you may find in fact is that with the signal cable twisted one way, the stylus skates outwardly FAST, and with one more twist, now skates inwardly fast. THAT is your (gross) setting point. You want to find the point where the twisting JUST gets the arm to skate inward.

THEN – HOOK UP THE ANTISKATING NYLON WIRE (or adjust the Vivenda Soundsmith device) AND add JUST enough Anti-skating to slow it down to the desired rate as described above. Using one or more washers (if needed) on the far arm of the anti-skating device will ADD antiskating (and slow down the arms inward speed) as will hooking the nylon wire in different positions up on the other arm. PATIENCE…….PATIENCE…..

Peter Ledermann/Soundsmith



Edits: 01/21/12 01/21/12 01/21/12 01/21/12

This post is made possible by the generous support of people like you and our sponsors:
  Signature Sound   [ Signature Sound Lounge ]


Follow Ups Full Thread
Follow Ups

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.