rumble issues - see old thread update


I originally posted this under amps
as I thought I might be experiencing clipping

looks like it's definitely turntable related and rumble from subtle record warpage is the main culprit

see my last comment on this thread

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1273520086

may check out with my outboard ZYX Artisian phono pre when I get it back from a friend

Tom
audiotomb
I think that if you filled the bearing all the way there should be no reason to worry about oil. There is no place for it to go. The bearing itself? Ah, no. ;-)

Got it this time. The one SRA turned out to not be a good match with the table. There is one layer peeled back, perhaps the only based on your results. BTW, have you tried the Gavia directly on the top shelf of the Craz? Heck, you could even move the Gavia to the floor since you're on a slab. Might tell you something.

I am not familiar with your amps and speakers, but it seems they are just going to move a bit with vinyl playback. Perhaps Atmasphere will have some input on this.

If things sound good, don't worry, be happy, and listen. Put the covers on if it bothers you. :-)
Tom,

I was just pointed to this thread. There's too much good inforamtion to sift through at the moment, but based on the names of the posters, along with a quick scan, it looks as if you've received good advice.

I likely missed some of the finer points, but here are some thoughts.

1. Same problem with all sources?

Do you get the same pumping when playing CD? I assume this isn't the case, but it needs asking

2. Changes in stands/shelves.

This strategy seems to be pointing you in the right direction. No time to comment on the apparent disconnect of suspending an unsuspended turntable.

The key point to mention however is, that with Vibraplanes, microscope tables, etc., the entire 'table is suspended - the critical relationship between drive system and platter is still intact.

Maintaining this fixed relationship between drive system and platter/bearing is key to the success of an unsuspended design, and placing the entire assembly on an air table is consistent with the design goals.

My expereience of a Townsend Seismic Sink on my turntables was essentially a whole lot of trouble for no improvement over a *well* *implemented* sandbox design.

I've never met Sorbothene that I wanted in the same zip code as my hi-fi, but I can't profess to having tried every last permutation. Let's just say that it's the last place I'd look for answers.

3. Cartridge.

Don't rule out the cartridge, just because the Tri-Planar/Universe is a ubiquitous and compatible combination. You might have a sample that's aging differently. Mount another cartridge. You've tried enough differnt things to not want to overlook this.

4. Oil.

It wouldn't hurt to re-lube as you've been running your rig for something like 3-4 years. I don't expect any changes here.

I'll try to work through this rather long thread as time permits, but don't hesitate to call me.

Cheers,
Thom @ Galibier
The key point to mention however is, that with Vibraplanes, microscope tables, etc., the entire 'table is suspended - the critical relationship between drive system and platter is still intact.
Agreed, and we go even further. In our setup the entire table + system + rack are suspended as a single entity, well away from the table and drive system. All our sorbothane floor supports see is a single, rigid mass of nearly 400 lbs. This is very different from sticking it directly beneath the TT feet or something. I tried that once, just for ha-ha's, and it sucks big time.

Agree that the connections between drive system, platter, bearing, plinth, armboard, tonearm, cartridge, LP and record clamp must be as non-compliant as one's components allow. The only compliance anywhere in our vinyl setup is Stillpoints instead of spikes beneath the plinth. As anyone who's tried them knows, they do ennable a tiny degradation of transient speed and dynamics, though most feel the reduction in sound floor makes for a worthwhile tradeoff.

It's about thoughtful implementation, as always.
Hi Doug,

Thanks for the clarification on your Sorbothene implemenation, as well as the validation that locating it closer to the source component is a non-starter.

Cheers,
Thom @ Galibier
What I find bothersome about the MinusK, and I fully admit I have no experience with it, are the reports of these going into oscillation by something like a cd drawer opening and closing. It seems that they do dampen out and work, but I can't imagine my gear on top of something that moves when queuing a record. I suppose I'd have to see it, but it doesn't sound comforting. :-)