How to set SRA after determining true vertical?

Greg, yes you simply stated it backwards. The cutter head stays in one plane but moves in two directions.

Imagine you have a nickel on your desk. Imagine that's the cutter head looking from the front. You put your finger on the nickel. You push it up and down, left and right. But it still remains in one plane -- the plane of the table.

I am thinking the cutter head acts more like a plow vibrating fom side to side. thus the record rotates under the cutting head as the head plows ahead vibrating either to the right or left, thus there is no downward cuttiing motion. that is why I prefer the vertical position.
I think I 've made enough empiracal arguments it's time to do some research.

Greg (and anybody else who seriously wants to know how this all works,) check out this page: YOU ASKED FOR IT !!

http://aardvarkmastering.com/westrex.htm

Note: until you get down to picture no. 9, you are only shown one coil, but pic. 9 and 10 clearly show both coils (at 45 deg. to the horizontal, 90 deg. to each other) each with a pin or "link" that is soldered to the torque tube. The cutter head or stylus is installed in pic. no. 11.

At the bottom of this page (I finally found one) is a line diagram of a Westrex cutting head:

http://aardvarkmastering.com/history.htm

Any questions?

i have a question, how can one adjust correct vta, without using microscopes and other equipment ? I use a Dyna. 17D on a JMW-9 tonearm, how would i be sure that the angle of the stylus is correct ?

Readster, basically, you're on the money or you're not. HOWEVER, it's perfectly valid to take the position that if you could get kinda, sorta, close to the money, you could live with that.

Here's how I'd go about doing that:

First, let me say that of a few different cartridges I've inspected (plus what I'm learning from folks who have taken the time to check using instruments) it appears that all cartridges with micro-ridge styli are built with SRAs in the following range:

At one end of the range, the stylus is vertical in the groove when the cartridge (top surface) is parallel to the record/platter. At the other end of the range, the SRA is around 1.5 deg. when the cartridge top surface is parallel to the platter.

In other words, if you got your cartridge parallel to the platter (which generally means your headshell and tonearm too) then you know this much: the SRA is somewhere between zero and 1.5 (+/-) degrees.

Let's say from this level position, you arbitrarily apply 1/2 degree more, or about 2 - 3 mm. at the tonearm post. So now you know that the SRA is somewhere between 0.5 degree and 2 degree (depending how much or little SRA was built into the cartridge initially) but of course you don't know which end of this range your particular stylus is at.

However you can tell by listening, IF you know what to listen for. Unfortunately, this kind of "informed listening" ability is most usually gained by my making SRA adjustments up and down from a correctly set SRA.

But basically it goes something like this (assuming everything else is set up correctly -- load, VTF, ASF, overhang, tangency, etc.):

Listen first to bass. Write down what you think you hear. Is there enough? If yes, how does it sound -- crisp with slam and attack or sort of rounded and/or muddy. If there's not enough or it sounds thin, then you have too much SRA. Reduce it until you have good clean bass without bloat. If it sounds bloated and muddy after you obtain good bass response, then you've gone too far, back off a bit.

Then (or if bass was OK to start with) listen to highs and midrange. If it sounds glarey or grainey or harsh in any way, it usually means (unless it's something else in your system) the you have too much SRA. Usually you won't have very good bass either, which confirms it's the SRA and not some component or cable. Reduce the SRA until the highs are silky. Still not enough bass, reduce the SRA a bit more, it won't affect the highs that much.

Were talking about tenths of a millimmeter here. So get yourself a set of automotive feeler gauges to help determine how much change you apply to the tonearm post (unless you have a TA that provides for easy adjustment of SRA/VTA)

Once you've got good tonal balance, see how you feel about image/soundstage. This is very cartridge/arm/TT dependent. But as anyone with a SRA-adjustable tonearm will tell you, there is one magic (SRA) spot with every record where the audio hologram just snaps into focus. It's very obvious and thrilling to hear.