Where do classical vinyl records get their rumble from?

Whatever it is, you would benefit from an old-fashioned ’rumble’ filter (other names were used).

You could use one occasionally via a tape or processor loop, or thru one with an in/out switch.

If in your system, only for some LP’s, that is tricky, best of luck. You could bring your good/bad lps to a friend’s system, see if it’s the same there.

If you came here, we could play and then if the rumble appears, engage my Vintage Feature Filled McIntosh mx110z Preamp’s ’LF Filter’.

"low frequency noise below 50 cps is reduced by pushing the LF rumble filter switch to the IN position. Low frequency acoustically coupled feedback is also reduced by this switch"

Being an old dog, I’m not living without all the features that are missing on much equipment today.

Oh purist's calm down. It's just maintenance to keep all the controls, switches, rockers clean and noise free. IMO you shoot yourself in the foot when you buy into featureless 'straight wire with gain'

I've run sources directly to my mono blocks, then thru everything, I must be deaf, you must be a bat if you truly hear a difference, and, suppose so, a meaningful difference? 

@ghdprentice 

Thanks for your thoughts!  I was starting to think the rumble was from my turntables, but I have a few records where there is no audible rumble so that completely exonerates the tables, in my view.  The tables are listed above in the original post - Holbo air bearing and Garrard 301 with upgraded main bearing.  My main cartridge is a DS Audio optical, renowned for delivering bass, and I have an 18" Velodyne subwoofer, so my system will play rumble if it is there.  It also picks up low organ notes!

@audphile1

Yesterday I played a superb recording of Mahler 7 conducted by Paavo Jarvi on Alpha 1207 which is a rare combination of great recording and great performance - no audible rumble.  Ditto for a direct cut disk of Beethoven sonatas from Chasing the Dragon VALDC012.

@elliottbnewcombjr 

Whatever it is, you would benefit from an old-fashioned ’rumble’ filter (other names were used)

I am going to argue that the record rumble is right where I paid good money to hear the lowest musical notes!  The SoulNote E.1 Version 2 Equalizer I am using does have a switch for low cut (I can't find any specifications) but by design, it only operates on MM and MC input.  Optical is not filtered.

Your "straight wire with gain" quote comes from Peter Walker of Quad, whose pre-amplifiers offered an array of controls for taming errant (and non-RIAA) recordings.  I am halfway through restoring a Quad 34 Control Unit (pre-amp).

The more expensive SoulNote E.2 Version 2 has an even bigger range of adjustments.  On the other hand, the top-of-the-line E.3 only handles DS Audio optical cartridges and only has a low cut filter!

@richardbrand 

you are absolutely right, I was thinking exactly that when I re-typed McIntosh specs ... "below 50 cps is reduced"

And, old dogs lose ability to hear highs, but not bass, so even more of a shame to cut what you worked hard and paid dearly for.

However, to temporarily solve a problem ....

"Low frequency acoustically coupled feedback is also reduced" may indicate that McIntosh is applying the low/rumble cut to any and all inputs (prior to amplification), maybe even the tape loop, to cut the output from the speakers to eliminate feedback, or the potential for feedback.

A look at the wiring diagram would reveal how it is implemented.

@elliottbnewcombjr 

old dogs lose ability to hear highs, but not bass

Our neural networks don’t lose the ability to hear timing, either, so spatial clues don’t escape us - apparently.

I do have a low cut switch - the on/off one on my subwoofer.

Seriously, the record rumble I hear on most classical records is there but I can put up with it. My question is really about where it comes from in all the processes leading up to pressing.  Some, usually expensive, pressings don’t have enough to hear it at the levels I listen at