Plinth concept for this SP-10: (see also Technics SP-10MkII turntable – Pt 2)
CNC router-cutting plywood for the new plinth:
Assembled plywood layers:
Special metal sub-ring ‘buried’ within the plinth, 4 x M5-tapped for fixing down the L-07D tonearm:
Test-layout for 12′ and 10″ tonearms:
Sanding the glue-laminated plywood plinth:
SP-10 test installation into the plinth (white ‘blonded’ fonish):
SP-10 chassis installed (note the 2 additonal wood-screws to ensure rotational rigidity).
6mm thick, laser-cut Stainless Steel baseplate (9.5kg):
‘Mag-lev’ support footers (10kg load capacity x 4):
Footer housings for mag-lev supports:
Finished SP-10 turntable (shown below alongside the Trans-Fi Salvation rim-drive turntable). Tonearms initially installed are:
The sound :
(Using Transfiguration Temper W and Koetsu Rosewood Signature cartridges, Fidelity Research FRT-4 moving coil transformer, Lounge Audio LCR Gold phono stage.)
First impressions – I was not surprised to hear excellent image focus & low frequency ‘solidity. However, I must admit that I did not expect to hear such an excellent overall reproduction with ‘transparent’ soundstaging with greater ‘depth’ & also ‘width’ perception. Also excellent resolution, high frequency ‘presence’, macro and micro dynamics.
With the Koetsu on board (loaded ~140 ohms via the FRT-4) bass power is much improved (compared to the Transfiguration Temper W), with a more ‘expansive’, less ‘clean-edged’ but larger ‘sound ‘picture’.
This is an idea adopted on some other Technic SP-10 turntables – using a threaded rod to connect a heavy metal bottom mass to the SP-10’s motor bearing above.
In our case, the 9.5kg bottom plate was threaded for a M12 x 1.25mm fine-thread Stainless Steel Hex Bolt with ‘jam nut’, This can be screwed upward to contact the motor bearing ‘thrust-plate’ underside and then jam-locked in place – arguably allowing the bottom plate mass to absorb any bearing or motor noise and also adding vertical support to the Direct Drive motor.
On audition, with the ‘Noise Sink’ bolt connected, the reproduced sound is more ‘taut’, less dynamically ‘open’ and a little constrained and ‘boring’. Without the Noise Sink, there is more ambient detail, more ‘air’, more ‘delicacy and ‘bloom’ to the sound.
Your preferences may differ, but this effect is not to my liking and seems to me to be similar to the sound when employing a record-clamp.
(First test-run with the Transfiguration Temper W cartridge and standard Technics platter mat.)
I recommend using the Trans-Fi Reso-Mat. It happens to be the same 5mm thickness as the stock SP-10 rubber mat, but provides a much more open and transparent sound, with excellent tonal bandwidth and dynamics. No real drawbacks, to my ear, noticeable so far.