Ortofon SPU #1S Stereo Cartridge

Description

Ortofon SPU #1S Stereo Moving Coil Cartridge.  Ortofon’s SPU cartridges have long been cherished for their musical prowess, remaining resolutely old-fashioned in terms of weight, low compliance and heavy tracking force.  Have a read about the 60 year history of the SPU on Ortofon’s website here.   While there are SPU variants that can be used in tonearms having fixed headshells, most SPU models come with integrated headshells, now fashioned from ‘ground wood and resin’.  So, to use an SPU, you pretty much have to use a tonearm with a removable ‘SME’ type headshell connector, but fortunately most of the tonearms that we like and sell fall into that category.

So, the SPU #1 cartridges are perfect for the newcomers to the world of SPU.  The SPU #1 S and SPU #1 E feature respectively Spherical and Elliptical stylus, High Purity Copper armature windings and terminal leads and a housing of grinded wood and resin composite.  Sonically, the SPU #1 models are genuine SPUs, known for their full-bodied and powerful music image, minimum of intermodulation distortion and an impressive channel separation.   In Ortofon’s quaint words, “with their linearity and full bodies, the SPU #1 models are a perfect solution for the playback of stereo recordings.”  We can’t argue with that.

Anyway, these are lovely things, and the SPU #1 models offer more than just a taste of what SPUs are all about.  Don’t take our word for that – have a read of Michael Fremer’s piece in Stereophile (September 2016):

“…To this day, Ortofon SPU cartridges enjoy cult followings in Japan and elsewhere. …There are many variants of the basic, iconic SPU design, but most are highmass, low-output, heavy trackers known for their old-school warmth and musicality…

…when I played my first record with the SPU #1… I immediately, and much to my surprise got what the SPU cult is all about. Most of what seemed to be missing were playback artifacts that ride along with the detail, along with the “visual” elements that help produce spatial context, including reverberant trails, initial transients, decay elements, etc. What was left were vivid, generously sezed, richly drawn aural images laden with textures and harmonic vitality. Whether you hear this as thick and slow or as a rich and full is a matter of sonic perspective…

…I’ve got plenty of mono and vintage stereo LPs. I spent a few days playing them through these SPUs (SPU #1 S or SPU #1 E – red.), and they all just sounded right and “of a time”…

…If you’re considering buying one of these (SPU #1 S or SPU #1 E – red.) – and assuming you have a compatible tonearm, in terms of both the SME collet and a medium to high effective mass – I suggest using a tubed phono preamplifier and a loading of less than 100 ohms. Unloaded, the new Ortofon SPUs could sound bright on top; that, in combination with their rich, full bottoms, produced an unpleasant discontinuity of sound.

I’m still not thrilled to track stereo LPs at 4 g – but the sound was so rich, warm, flowing, and relaxing, the images so round and so generously sized, that I conquered my fears of worn record grooves and spent many pleasant evenings drinking wine and visiting the 1950s and ’60s. If only I knew then what I know now!”

Spherical Tips?

Spherical tips (also commonly known as conical tips) are nowadays pretty unfashionable, and audiophiles are understandably drawn to cartridges sporting more aggressive tip profiles (line contact, micro-ridge etc) that will ‘dig out’ more detail from the record grooves.  The Ortofon SPU#1S, SPU Classic G and SPU Wood A all use old-fashioned spherical tips, and in the case of the SPU#1S and SPU Wood A, these are even less fashionable bonded tips, where the diamond is set into a metal ferrule, rather than being ‘nude’.  Some people will get terribly excited about tip profiles and tip mass, which here are clearly higher than in most modern cartridges, but good cartridge designers specify materials, masses and suspensions to work together, and that’s what Ortofon have done here.  Spherical tips do have some advantages over sharper tip profiles – they are immune from zenith alignment errors (how ‘square’ the tip sits in relation to the groove walls) and they are quite forgiving of SRA/VTA errors (up to a point).  Ultimately, SPUs are all about reproducing music with vigour, colour and enthusiasm, so don’t get overtly tied up over theoretical gains with different tip profiles – partner the SPU#1S with a really good, heavy arm, and a well specified SUT like the 1:26 gain Sculpture A Mini Nano, and you’ll soon forget its old fashioned specifications!

Step-Up Transformers

We recommend that you pair the SPU#1S with a good moving coil step-up transformer (SUT), for best sound quality.  Gain and impedance matching are critical to getting the most from these SPUs – plug them into a regular MC phono preamp and you could well be disappointed by the sound.  But, through a good SUT and these things sing like their lives depend on it – expect a bigger, more expansive, colourful, dynamic and expressive sound, compared to running the SPU into that regular MC phono amp.  By far the best SUTs that we’ve heard with SPUs are the 1:26 gain ratio Sculpture A Mini Nano SUTs, which are sensibly priced and sound quite amazing.

Ammonite Audio Inspection and Testing Policy

Please note that we inspect and briefly test each Ortofon SPU cartridge before sending out to the customer, so we do cut Ortofon’s factory seal on the packaging.  Visual inspection is just to confirm that the cantilever and tip are correctly fixed and aligned.  Our listening test involves setting the SPU up with recommended VTF and with the tonearm level, then briefly listening to outer and inner tracks of a known LP.

Technical Data

Output voltage at 1000 Hz, 5cm/sec. – 0.18 mV
Channel balance at 1 kHz  –  1.5 dB
Channel separation at 1 kHz  –  20 dB
Channel separation at 15 kHz  –  10 dB
Frequency response – 20-20000 Hz –  ± 3 dB
Tracking ability at 315Hz at recommended tracking force *)  60 µm
Compliance, dynamic, lateral – 10 µm/mN
Stylus type – Spherical / Elliptical
Stylus tip radius – R 18 µm  / r/R 8/18 μm
Tracking force range – 3.0-5.0 g (30-50 mN)
Tracking force, recommended – 4.0 g (40 mN)
Tracking angle – 20°
Internal impedance, DC resistance – 2 ohm
Recommended load impedance  > 10 ohm
Cartridge body material – Ground wood and resin composite
Coilwire material – High Purity Copper (OFC)
Cartridge colour – Matte black
Cartridge weight – 30 g