Tube Phonostage Causing Rumble and Noises

I’m curious if you have a hot spot and the turntable is sitting on the peak of a standing wave.  
 

I would try to move the turntable forward off the wall or just anywhere.  Also consider bass absorption on the front wall.

i had not a rumble, but a low, loud, buzz (or hum!? No clue what he right term is) that would gradually appear (especially listening to “sticky fingers” Riling Stones)  if my volume was too high using the turntable.  It wasn’t coming off up the turntable, either.  This is a super-isolated VPI Avenger Titan, siting on a 3 inch slab of hardwood with rubber feet, sitting on a Symbol Audio table.

i read somewhere that the cause could literally be sound vibrating the stylus or cartridge.

I had extra GIK bass trap panels and lined one up right behind the audio cabinet, just sitting on the floor with about two feet sticking up so it absorbed the “bounce” off the back wall.  Immediately went away.

i then did a cleaner install.

@mulveling 

“With the Fatboys (both uni and gimbal) the problem is mitigated enough to no longer be a concern.”

Sadly, this is also the Fat Boy — Kevlar 3D printed.

I also have the Esoteric Grandioso turntable.  Same issue when I used the Van den Hul Frog Gold cartridge, so I think it’s the cartridge, which is otherwise lovely.
 

I two huge SVS PB 16 ultras and Bowers 800 (Diamond) to fill a big space and I like to listen loud.

I measured and had an off the charts standing wave peak about 1.5 feet off the front wall.

Regardless of what is picking up the feedback, the base trap solved the issue.

@mulveling 

I’d love to say I’m an acoustic genius, but I figured out it was a standing wave because every time I went to look at the turntable to figure out what was going on, the sound would rapidly fade (and my heart would start beating way too fast, which I figured out was relevant later).

A very Heisenberg’s cat situation.  I’d look and the sound would go away.

Eventually it dawned on me that my body was breaking up the wave.  Did a little trial and error and then tests to confirm.

The weird heart rate is a classic symptom of intense subsonics, which I knew from working in a haunted house when I was a teenager.

@yoyoyaya 

The 3D printed tonearm is one of the Van den Hul recommended tone arms for the Frog Gold and vice versa.  In fact, they market together.  The mass of the 12 inch dual pivot is 12.5g.  They sound wonderful together.

Also note that the problem (as stated above) reproduced with the cartridge on the Esoteric Grandioso with its TA-9D tonearm which is a radically different design.

And there is no fault invovled, except the odd acoustics of my room and my tendency to listen at high volume.  I suspect any sensitive cartridge would have had feedback.