Sorane SA1-2 Tonearm

NOTES:

• The Sorane SA1-2 is the same product as the Abis SA1-2.  The specifications and manufacturer are the same.  As The Abis brand name was changed to Sorane in 2017 summer, the products in this website/review are now called the Sorane, with unchanged model number.
• For more about the manufacturer, visit this link.
• I am looking for dealers.  Please use the contact form below.  I prefer working directly with plinth makers and those with the skill needed to install tonearms.  If that is you, please contact me.
• I am offering special pricing on Yamamoto Sound Craft headshells to existing and future Sorane owners.  The Yamamoto HS3, weighing a little over 8 grams, is a perfect headshell for the SA1-2, especially for medium compliance cartridges, like the Grados.

Reviews

USA

• Sep/2015Abis SA-1.2 Tonearm, Pyon Sound,TiGLON.StereitimesDave Thomashttp://v2.stereotimes.com/post/abis-SA1-2-tonearm-pyon-sound-mc-master-l-step-up-device-and-tiglon-mgl10p-tonearm-cable
• Oct/2017SA-1.2 Recommended Components / Class- A RatingStereophile 
• Oct/2017TA-1L Recommended Components / Class- B RatingStereophile 

Germany

• Dec/2016ZWEI STARKE ARMELP magazineThomas Schmidt

United Kingdom

• Apr/2017Abis SA-1.2Hifi NewsAdam Smith

France

• Nov/2015Abis SA-1.2 tonearmTNT FranceGeoff Husbandhttp://www.tnt-audio.com/sorgenti/abis_sa12_e.html

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The Sorane SA1-2 was added to Stereophile’s Class A list of recommended tonearms in the April 2016 issue.

The sound of the Sorane SA1-2 tonearm is powerful and engaging.  Due to its substantial construction, cut from billet aluminum, and fastened together with great care, there is virtually none of the resonance associated with S-shaped arms.  In contrast to classic tonearms from the past, which suffered from resonance and irregular bearings, the SA1-2 provides the ideal mass for a cartridge like the Denon DL103 or Ortofon SPU (also, mono cartridges like the DL102, or even antique cartridges like the GE VR and Fairchild). 

The weakness of low mass tonearms is that they make poor matches for medium and low compliance cartridges.  The Sorane SA1-2 gives you precise radial-bearing performance and low resonance, while providing the necessary mass for medium and low compliance cartridges.  

Key to the performance of the Sorane SA1-2 and SA1-2B is the use of very high grade ball bearings. Bearings used for horizontal movement are axial-loaded, angular-contact, thrust-bearings. These thrust bearings have zero play and are held in contact by gravity.  You can think of them as acting like a unipivot, but with more than one contact point.  Because they have two tapered seats, they will self-align in the presence of a load (gravity), have exceedingly low moving friction and are especially suited to angular and axial loads.  

The angular error needed to misalign these special bearings, commonly used in high precision machinery, are so severe that they fall well outside the operating conditions for a turntable (if you need an arm for playing in zero gravity, or turned at 90° to earth’s gravity, you will be forced to use a different style of tonearm).  Traditional deep-grooved ball-bearings are not specifically designed to take an axial load, being better suited for radial loads like a wheel bearing, and they suffer from much higher rolling resistance.  While the quality of the bearing materials are a key to success, the proper choice and loading of bearings is just as important.

Angular Contact Thrust Bearing

Also key to the performance of all tonearms, and especially the SA1-2 and SA1-2B, is the resonance characteristics of the arm “tube”.  The SA1 design is built from four pieces of billet aluminum, milled to tight tolerances, finished, fitted by hand, and torqued to settings determined by experimental observations.  The torque values chosen introduces preload on the fasteners, and produces hysteresis stresses (basically, inner friction) in the crystalline structure of the metal.  These stresses damp vibration by forcing the crystalline structure to be more tightly bound, than when in a free state.  The elastic and anelastic properties of all four pieces are slightly different, preventing dominant acoustical nodes from developing.

When properly machined, fitted and torqued, a unit composed of several milled pieces will have lower maximum resonance, with several smaller resonance frequencies, compared to an armtube composed of one piece.  These statements are backed up by scientific study into weapons systems, rockets, engines, structural elements, etc..  Resonance is a key source of failure, and the research proves the point:  a single piece of billet material can have 1~3 dominant resonance frequencies, with one resonance frequency dominating the performance of the structural member. If you think about the bars that form the notes on a xylophone, you will have a practical understanding of the limitations of “one-piece” arm tubes.  In practice, a combination of surface finish, damping materials, shape, density, alloy, crystalline structure, fastening technique, and fastener preload, among others, will determine the relative distribution of acoustic energy in a tonearm.  Since extremely dense (heavy) materials, like depleted Uranium, don’t easily lend themselves for use in tonearms, a holistic approach is necessary.

The rectangular shape, the tight assembly by hand, and the nature of billet aluminum creates a low-resonance design that is essentially quiet.  The preference for 12″ arms has more to do with compliance match, than the theoretical advantages of a 12″ arm (which are nullified by the use of a spherical tip).  The SA1-2 and SA1-2B maximize the possible geometry at 9.4″, while excellent damping and high mass give it the tonal balance of 12″ arms.  With the SA1-2 and SA1-2B, the tracking error is very low, while the superior sonic signature of the billet aluminum arm parts, and the mass equivalent to most 12″ arms, gives 12″ arm sound in a compact form.  It is ideally suited for low to medium compliance cartridges, especially those that are particularly problematic when it comes to mistracking.  

Sorane SA1-2 Geometry

One thing not always stated in tonearm literature is whether the tonearm in question uses the Stevenson, Baerwald or Lofgren geometries.  In many cases, older arms adhered to the Stevenson standard.  The theory behind the Stevenson alignment is that it lowers distortion on the inner grooves, which are often the most challenging when playing symphonies/operas/soundtracks etc..  Since then, there was a sea change.  Pop and rock outsell classical several hundred to one.  In light of current trends, the Baerwald geometry works better for many pop disks, which tend to have high levels of modulation in varying areas (at the discretion of the producer and group, the loudest track could be anywhere on a disk).  

Since there is no correct answer to this question of geometry, the Sorane SA1-2 geometry was chosen to fall at a point between Stevenson and Baerwald (Lofgren A).  You can adjust the overhang to make the arm perform more like the Baerwald (Lofgren A) or Stevenson geometries, if you desire.  

Specifications

Jasmine SME2R10 Tonearm Base Converter

The SME2R10, created by Jasmine, is a very high quality adapter that will allow Sorane tonearms to be adapted to armboards drilled for the SME tonearms. They are made of quality billet aluminum and both finish and machining are excellent.

Though the situation is somewhat dependent on the competency of whoever drilled the original armboard holes, the range of adjustment of the SME2R10 will allow an Sorane SA1-2 to be used in place of a 3009 or 3010.

To compare the practical distance, or spindle to pivot, here are a list of arms of similar length.

It can be seen immediately that the TA1 is very close to the 3009, and the SA1-2 is very close to the 310 and 3010. What is not as apparent is whether or not the SA1-2 will fit in place of a 3009. If the center of the SME base for an 3009 is drilled at 215 mm, then the SA1-2 will definitely work. There is a difference of only 7.3 mm (0.287” or 19/64”). The range of adjustment for the Jasmine SME2R10 is much greater. It will work.

What is a slightly tougher fit will be going from SME 3012 to Sorane TA1L, with a difference of 14.6 mm, or 0.574”. It is possible that some boards will allow enough room. Again, it depends on the choices made when the armboard was drilled for the 3012.

Obviously, if the SME base is mounted on an adjustable armboard or “pod”, there shouldn’t be a problem with geometry, and the Jasmine SME2R10 will allow any Sorane arm to be quickly substituted for the original SME arm.

The adapter is available on eBay from Jasmine.  

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