TECHNICS SP-10MkII turntable – Pt 4 what we’ve learnt so far

What we have learnt so far, with this SP-10 MkII turntable…

Building the ‘plinth’ (see TECHNICS SP-10MkII turntable – Pt 3) and trying to obtain the best sound from this turntable has taught us a number of things.

And also about optimising Direct-Drive turntables in general.

This journey is on-going, but I feel that we can say the following:

• Replace the original rubber platter mat with a less-solid type mat. (The TransFi Reso-Mat works best for me.)  This will provide an immediate improvement.

• Direct-Drive turntables behave mechanically quite differently compared to Belt-Drive turntables.  Therefore, the mechanical requirements are different.
• Unlike most Belt-Drive turntables, the platter on Direct-Drives is directly connected to a very high-torque motor. So, rotational stability (rigidity) is paramount.
• Be sure to fix down the SP-10 aluminium chassis solidly to the ‘plinth’. If necessary, add additional screw-fixings (see TECHNICS SP-10MkII turntable – Pt 3).

• The turntable is best supported upon rotationally solid, rigid ‘feet’. (Unlike the majority of Belt-Drive turntables.)  ‘Soft’ or ‘mag-lev’ feet, do not work best on a direct-drive turntable like the SP-10.
• The motor itself must be solidly anchored rotationally.  If this is achieved, then transient ‘leading edges’ are sharper and clearer. (Remove the mechanical brake on the SP-10, or replace the plastic brake guide with a metal part.)

• Direct Drive turntables are capable of maintaining very good musical ‘timing’ and ‘control’.  Speed control circuits like the SP-10’s quartz-crystal referenced, feedback speed control, can produce very good ‘stop-start’ clarity of sounds.  Very good ‘pitch stability’ also allows harmonic information, harmonic ‘decay’ and ambient ‘clues’to be revealed and heard more clearly.
• Surprisingly, stereo ‘soundstaging’ can be more ‘transparent’ than with Belt Drive turntables.  Perhaps this is not surprising, as the above speed ‘control’ allows ‘images’ to be more clear and precisely located, and thus the musical ‘soundstage’ to appear more ‘open’.
• The ‘noise sink’ idea of contacting a heavy mass ‘sink’ under the main bearing’s thrust plate, is non-beneficial to the sound (in my opinion) – dynamic range becomes ‘constrained’, ambient ‘air and delicacy are lessened.  The sound becomes more ‘taut’ and…’boring”. (To me, this effect is similar to when using a record clamp on the record platter .)

 

The still-to-do list includes:

• Damp the SP-10 top chassis.  A ribbed aluminium casting, it ‘rings’ surprisingly. (This may no longer be necessary with extra fixing screws now installed.)
• Damp (or remove) the cast alloy bottom cover.  This is heavily paint coated, but still resonates.

• Damp and increase the mass of the motor bearing base, a ribbed aluminium casting.

• Damp the Sub-platter magnet rotor, the thin sheet-steel baseplate holding the rotor ring-magnet. Also, this is attached to the Sub-platter with only 3 screws.