SPU / SME setup advice

[slammed56]

Hi Guys
Any SPU/SME users out there that can help me setup my SME 3009 series 2 non improved and Ortofon SPU
I keep seeing contradicting info regarding the correct Spindle to Pivot distance , anyone know exactly what this should be set at ?
I’m using a Clearaudio alignment tool (similar to the Dr Feickert)
I’ve tried various distances that I’ve found online but still can’t get the stylus to sit in the correct position on the grid
222mm seems the best but it’s still leaving the stylus about 5mm short of where the protractor says it should be , I’d usually just slide the cartridge forward in a standard headshell but being a fixed SPU this is not possible
Any advice would be much appreciated

 

[Tony L]

Which SPU do you have? If its the short-body ‘A’ type you won’t be able to align it in a standard SME arm.

PS Remember the SME geometry is Stevenson, not Baerwald, so inner null is at 60mm.

 

[Craig B]

Yes, if yours is an 'A' type SPU, you'll be needing an Ortofon SPU APJ-1 adapter.

 

[slammed56]

Thanks guys
It’s a old SPU GT model , so standard headshell not the shorter A type

 

[Craig B]

The Clearaudio alignment tools are to IEC which assumes an inner null of 60.325mm.

As to its use with SME mount, like the Dennesen Soundtractor of yore, of which these are copies of, an accurate pre-adjustment for a given tonearm pivot to spindle centre distance must be made before attempting cartridge alignment. Unfortunately, with SME tonearms, pivot to spindle distance is a moving target, as the tonearm pivot is slid along the baseplate to facilitate overhang adjustment. As such, the best guess starting position must be that of the centre of bedplate to spindle centre, which, if the arm base has been positioned properly, is 215.4mm for 9" SME tonearms. Starting with the alignment tool beam set to this measure, once the tonearm position has been shifted to achieve nearest visual alignment on the grid, the tonearm pivot to spindle distance will have changed, hence, one must readjust the alignment tool beam to the new pivot to spindle value and recheck/adjust/repeat as necessary until aligned.

IOWs, it is much easier to simply use the standard single point protractor provided by SME.

 

[slammed56]

Thanks guys ,
I really should use my reading glasses more often !!!!!
Tony hit the nail on the head ,my gauge can be setup for various inner null points 60.325,65,70 and 75.......I had it set to the clearaudio recommended 75mm...Doh !!
After switching this to the correct 60.325mm all is well , panic over

 

[Craig B]

Ah, you must have the deluxe 'Multi Installation Gauge' then!

Glad to hear that you've got it sorted.

 

[slammed56]

Cheers Craig
Ive had the gauge for years , didn’t realise they’ve streamlined it to a single null point on the newer model

 

[Saknar]

I have the same problem with SME 3009 non improved together with SPU in a SPU G headshell. When I measure the effective length it is 239 mm.
It should be 228.6 mm. That makes it impossible to mount the arm with pivot to spindle 214 mm as it should be with 3009. The templates to align the cartridge will not work here.
But if you look at SME 3010, it has an effective length 239.3 mm. The same as mine 3009 with SPU G headshell.
If you use the data for 3010 with spindle pivot 222 mm you get an overhang at ca 17 mm and this will work better

When you use an SME 3009 with SPU cartridge in a SPU G headshell the tonearm behaves more like an SME 3010 system