SME Model 20/12 versus TechDas AirForce V or Suggestions for a 2 tonearm TT

Never heard either one, but I can vouch for using two tonearms. As for isolation, get a minus K platform: costs 2-4k.

The V would have to go on a MinusK platform which is another 5K. I do not care much for TechDas products. I think your SME is a better turntable. My first choice would be to sell the Graham and the 312S, mount the CB and you will never look back. If you have to do two arms then a Dohmann Helix 1 is the best way to go. The poor man's version is a Kuzma Stabi R on a MinusK platform. Being a sadomasochist I am thinking about taking a Sota Millenium, removing it's suspension and placing it on a MinusK platform so I can mount two arms, a Reed 5T and a Schroder LT. I am a sucker for vacuum clamping.  A turntable without adequate isolation is not an option. 

I went for Vintage Direct Drive Quartz Locked on composite 7 layer deck

JVC TT81 spinner

on JVC Plinth CL-P2 (two removable armboards)

then I added a 3rd arm, had to be a very compact Mission/Jelco to fit within the dust cover

Notice, I added a deeper glass shelf as the Plinth is very deep

look here if image is distorted

Elliott’s Main System

I helped my friend put together a Luxman PD444 Two Arm Table, it is wider, not deeper like mine. Elegant simplicity with terrific technology

The Luxman includes an A/B switch so only one phono cable out.

Mine, 3 phono cables to a SUT with 3 selectable inputs.

@elliottbnewcombjr and neither turntable is adequately isolated. 

If you do extend your investigation to A/B Comparisons. I f carried out at the Dealers do make sure both TT's are demo'd on identical mounting along with identical supporting Audio Devices downstream. The identical Cart' set up may be more difficult to achieve.

If a home demo' can be arranged, this will be even better for your deliberations to follow. 

The more effort put into discovering methods that can be adopted to mount a TT, with the intent to decrease ambient energies being easily transferring to the Styli. Creates a TT, that can become unrecognisable to when it has been used on a Mount that has not been considered to substantially reduce / resolve the transferral of ambient energies.

mijostyn

my wood floors are springy, isolation from that movement is beyond difficult, sadly made me part with my beloved Thorens TD124 which has a bearing very susceptible to vertical movement.

Both the JVC Plinth and Luxman Plinths have special technology, but neither can deal with my floors.

Each shelf of the rack is individually isolated via compressed rubber, the stands on top supporting the glass shelf have compressed rubber spacers top and bottom, and finally, a set of rubber/cork blocks are the high tech solution that solved it here.

Cork and Rubber Pads, I wrapped mine in black tape,

thorens with vacuum, keep all or sell some least favorite arm(s), note mine, Luxman, this one has a dust cover, many do not.

thorens TD 226 with 2 arms

THAT dust cover is fine for down time, in between listening sessions, but it should be stored away somewhere when you’re using that TT. It’ll resonate like a drum.

garrard 301 in a blank 3 arm box.

check arm clearances when top is closed

garrard 301 in a blank 3 arm box