Setting VTH Acutex

Roger G F

Active Member
On the Acutex carts it appears that the shape of the Cartridge has the needle base parallel to the record surface. Should I set the VTF based on that surface or just get the arm level to the world when playing a record?

Thanks for your input.

Running a 412 STR.
 
Please describe what you mean by the needle base. Are you referring to the end of the cantilever at the point where the stylus is attached?

John
 
Yes. The stylus base, red plastic on my 412 STR seems to be designed to be parallel to the record.

Let me know your thoughts on setting the VTH on this cart.

Thanks!
 
This is what he means.

38447666235_f61d2ce3a7_b.jpg



But I set my 312 at about 1.8gm's . I set the VTA with the arm so the arm is parrallel. Then look at the stylus and see how it rides on the record and in the groove.
The STR's ride deep in the groove compared to some other stylus's I have had. You then might want to adjust vta ( you cal it VTH ) a bit higher, like a mm or two. One thing I found is that after a few plays you hear som distortion look at the needle, i bet it has a fuzz ball on it. This is from it digging deep in the groove. This will happen even more after a record cleaning. Reason is that the record cleaning my lossen up some of the deep groove gunk that the brush and even a vaccum cant get out all the way. The STR stylus finishes the job ! lol I have been dealling with this for the past two days. but playing the record a second time after the needle digging deep you really get to hear what is there in those grooves.... Magic !!!





Athanasios
 
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Hi Roger G,
I have an Acutex 420 STR in my Pioneer Pl-570 and play like that (look at the photo).
Regards.
 
I don't know what VTH is, vertical tracking height perhaps?

Generally speaking, cartridges are designed so that they have the correct VTA* and SRA** when the mounting surface of the cartridge body is parallel to the record. So, assuming that the cartridge is mounted flush with the surface of the headshell, you'll have the correct SRA/VTA when the arm and headshell are parallel to the record's surface. Both SRA and VTA are also influenced by the amount of VTF*** applied. Too much will cause the cantilever to deflect more than intended, putting the VTA at too shallow an angle and the SRA to lean backward. Too little VTF will cause the reverse to occur. The 412 STR likes about 1.8g.

John

*VTA (Vertical Tracking Angle) is the angle between the cantilever and the playing surface of the record. Generally, it's 20° +/- 5°.

**SRA (Stylus Rake Angle) is the angle between the stylus, as determined by its vertical axis, and the record surface.

***VTF (Vertical Tracking Force) is the amount of pressure the stylus exerts on the record, measured in grams or fractions of grams.
 
Thank you both for the information.

John. I have the same cart as you that I bought in 1979. Sure would like to find a replacement stylus for it!
 
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