Turntables currently considered top of the range. Do you know what they are ?

@dwette 

Wow, that's an awesome find. Seems like a ridiculous bargain in this context. I've spent this kind of money on just a couple of CMS platforms, and they surely don't help solve problems in bass frequencies - which (I imagine) the Minus-K should soak up like nothing, based on the physics. Like @tomic601 , I should've revisited more recently.

@mulveling My current thought – if I upgrade to Master Innovation – is to get a three-shelf HRS EXR rack for the phono-stage and TT, with a Minus-K under the TT. I'll repurpose the HRS R3x isolation base I have (with the right feet) for the phono-stage.

If you guys want to see something wild - check out these 2 video clips I made a couple years ago, with a VPI Aries 3, stylus in groove (at rest), and system on with volume set to "loud" listening level. This was my "energetic" problem room (small office).

https://imgur.com/a/HMASPUi

The 1st video shows extreme excitation at ~ 100-ish Hz from lightly tapping the shelf surface the TT sits on. It’s literally like a drum. Laptop speakers won’t reproduce this frequency; you need headphones or desktop speakers. And turn the video volume up. I could absolutely hear this frequency creep during playback, from feedback. It sounds remarkably like a ground hum, except that it rises as you increase volume. At a certain point, it can runaway (very bad, had to keep a finger on mute).

2nd video shows a greatly reduced effect, even as I slap the platform much harder! And it’s at the same system volume level. This is thanks to the metal 10.5i arm and HW-40 feet (squishy foam - with hockey pucks for spacers), versus the 3D arm and Classic Signature feet (hard - with Herbie’s giant fat dots for spacers). I should have made a video with the same feet, to show that much of the blame actually goes to the 3D arm. Fatboy arms were a similar story.

That’s a not-cheap CMS Sotto Voce rack and $2K Platinum shelf. Completely useless at this frequency! In the end, I think the rack’s architecture, table plinth design, and 3D tonearm are all to blame. And the Avenger Reference did nothing to help here. I thought its tripod plinth design might help, but it didn’t. Might have a video of that floating around somewhere.

Anyways, the Clearaudio Innovation compact had NO problems at 100Hz, but you had to watch subsonic feedback for woofer flapping (dangerous) - that’s from the float bearing IMO (again, the Master adds enough mass it’s less problematic). You can put this on a Townshend spring platform and it helps a lot! The problem with the VPIs, is their size makes it hard to fit onto a Townshend if you’re space constrained. I guess I should’ve tried the pods.

And the SOTA Cosmos, of course that does fine no problems :)
If I could re-do the rack choice I’d get an Adona with the cross-bracing. I think rigidity - in all directions - is a rack’s #1 job.