Odd tonearm - turntable set up, advice requested

[Lucerne]

I'm hoping that some of the resident turntable gurus could cast some light on the issue I have with a recent TT buy as illustrated on images below.

The pivot to spindle distance measures just over 220mm with effective length around 240mm but the only way of getting even close to any alignment is by pushing the cartridge as far back as it will go. Am I missing something obvious or is the tonearm mounted in the wrong position?

Its an Opus3 Continuo, with unknown arm, may be a one off but appears well made (unipivot) and I would have thought whoever made it had a decent understanding of set-up geometry.

https://i.imgur.com/TJgixY1.jpg

https://i.imgur.com/TqU9Ij4.jpg

Any advice gratefully received,

Cheers

Neil

[willbewill]

I wonder if this originally had the parallel tracking arm which has been replaced by this unknown one but has used the same mounting hole whereas it should have had a slightly longer pivot to spindle mounting distance/

[Lucerne]

That’s exactly what I was wondering...there’s a clean hole and just 3 fixings so it’s not been adapted to fit, in which case that would be a bit annoying:(

If it is the case, what is the best way of calculating pivot-spindle length from effective length (and is there a way of accurately determining it from arm measurement- pivot to end of head shell mid point or that minus x mm to normal stylus/overhang position?). Luckily the slots are long and it should be easy enough to relocate the arm position without it being visible.

[Lurch]

Try 211mm (Linn geometry).

Sent from my I3312 using Tapatalk

[Barry]

Are there no marks or labels on the tonearm to identify it?

If you can identify the tonearm, then you can find the details of the arm's geometry using vinylengine.com, from which one can calculate the two null radii.

[walpurgis]

Are there no marks or labels on the tonearm to identify it?.

I'm fairly sure I saw these offered on ebay by a Chinese/HK seller a couple of years ago. They caught my attention as they looked well made.

A poke about on AliExpress may find something similar.

[Lucerne]

Thanks all,

I'll have a look around. It does look well made, the counterweight is set on a micrometer screw which gives nice, accurate VTF adjustment.

I have measured the EL at 240mm, which suggests P-S of 222.3mm, and re-reading the Feickert its actually around 215, so its definitely in the wrong location...better get the drill press warmed up!

[Lucerne]

AliExpress revealed this looks like an early version of the FFYX tonearms. Same weight mech, similar detailing elsewhere, no info on set up but looks straightforward to reset and the head shell slots are long enough to allow a bit of leeway.

Thanks for info all,