Tips for setting up an advance ball

[piaptk]

I have an advance ball for my Presto head, but I abandoned trying to use it a long time ago because I could never get it to work right. It would always lift the needle and leave gaps in the cut. I played around with it for quite a while and just couldn't make it work.

Now that I know a little more about what I'm doing, I'm going to give ti another go. Anyone have any tips or tricks for setting this thing up?

[Aussie0zborn]

Not sure how the advance ball on a Presto head but on the Westrex 3D-II I never had this problem. The only trick with the Westrex advance ball was to position it so that the the stylus cuts directly into the light scuff mark that it left otherwise the scuff mark would show on the land and this would result in a very dull looking record. This may or may not apply to the Presto advance ball.

[Self-lather]

I have an advance ball for my Presto head, but I abandoned trying to use it a long time ago because I could never get it to work right. It would always lift the needle and leave gaps in the cut. I played around with it for quite a while and just couldn't make it work.

Now that I know a little more about what I'm doing, I'm going to give ti another go. Anyone have any tips or tricks for setting this thing up?

Umm not to sound dumb, but what is an advance ball?

[piaptk]

It hangs off the side of the head and rides along the disc to keep the depth of the groove uniform. if the disc is warped, the ball rides on the warp, and lifts the stylus to keep it from cutting too deep.

[Self-lather]

It hangs off the side of the head and rides along the disc to keep the depth of the groove uniform. if the disc is warped, the ball rides on the warp, and lifts the stylus to keep it from cutting too deep.

That sounds rad. I wonder if I could do a DIY one. Anyone have a pic?

[Prestofan]

Have you increased the weight of the head? It needs to be much heavier than without the ball so it will ride. Try that

[andybee]

here is a pic:

http://www.aardvarkmastering.com/heads.htm

[Angus McCarthy]

I've been thinking of Ghetto-rigging some kind of advance ball to my homebrew lathe. The ball looks absolutely tiny in those pics. In theory though could a polished marble do the same job or would the larger surface area create problems?

Would I maybe be better off going with something like a small glass bead, perhaps?

[markrob]

Hi,

I played around with using an advance ball at one point. I used a small glass bead that my wife had for her hobby. Here is a picture of what I did.

http://home.comcast.net/~markrob1066/pwpimages/Advance%20Ball.JPG

The problem I had was that in order for the ball to work well, you need to be in close proximity to the stylus. If not, the plane reference could differ locally from the ball contact point to the stylus. At the time, with my DIY head, I could find a simple way to accomplish that, so I went back to a floating system. Overall, I really don't see the big advantage of the ball vs. a floating system.

Mark

[emorritt]

Presto actually had primitive advance balls on a few of their heads. I have one somewhere and will post a pic if I can find it. It was nothing more than a highly polished steel point attached to a flexible metal strap attached to the bottom of the cutting head case. The depth adjustment was a small threaded rod on the opposite side of the head with a thumbwheel at the top and two supporting posts on the side of the head. Will look for it. If I recall, it worked fairly well and didn't mar the blank as with a much heavier head like a Westrex.

[grooveguy]

Mark's right about the difference in the record surface plane; that is, the difference in the vertical location of the record surface between the advance ball and the stylus, even though it's usually less than 0.1 inch between the two.

I have a Presto 1D with the advance ball (and I think it's sapphire, not steel); the ball can be unscrewed and located either to the right or to the left of the stylus, depending on whether you are cutting inside-out or outside-in, respectively. I tried it, back in the '60s, when I was using the 1D, but never had as good luck as with determining cutting depth with an adjustable counterweight and spring.

Some "advance ball" assemblies used a piece of felt instead of a radiused ball, which sounds better to me as the surface height reading would be integrated over a larger area, rather than being a specific point 'x' distance away from the stylus.

RCA, with their 73B, made much of the advance ball, and for good reason. The cutterhead used in the 73B was a long, horizontal-format head, rather than an upright one like the Presto, Fairchild, Cook, etc. For some reason, and I am not at all sure why, a low-slung head seems to "chatter" more than a vertical one. That is to say, the head is easily put into a vertical oscillation mode, which varies the depth of cut at an audible rate. Not a huge deal for mono, but unforgivable in stereo. (Oliver Read, in his book The Recording and Reproduction of Sound has a few pages devoted to vertical chatter.) A dashpot was traditionally used to dampen this, and I know for sure that the RCA 73A had a dashpot, as did the Presto 8DG.