Thumbs up for ultrasonic record cleaning

What @slaw said. Except I use 5 minutes per rotation. I even did the same experiment.

audiom3

once records are US cleaned, the differences between warm and bright recordings are even more substantial.

Agreed! If you really want to hear what's on your LPs, there's no substitute for US cleaning, imo.

Great thread! I've been using a USRCM for a couple of years (I guess that may put me in the 'early adopter' catagory) however, I would not say I'm any expert at it, mainly due to a lack of time to really dial in the procedure. Where I'm at today is: Vinyl Stack system (though I built my own stand for it) with a 40kHZ bath, using the "Rushton method fluid", though I started with just distilled water and have moved to a 'chemistry'. 1 micron filter with a 1.2gpm pump. Being an 'early adopter', the timing was shorter than what most of you have described: I've been using 5 minutes. Heat is a must (~40C, I find the temp goes up with sonic usage, too). Is everyone drying with a vac? I have been doing that...but I really don't like the idea of touching the record after cleaning! So - I'm building a blower/dryer rack. Air is filtered, and really 'blows'. QUESTION: after pulling the records from the chemistry bath, how should I rinse? with the distilled water + alcohol mixture, then dry? I don't want any residue left on records. Or spots :)

Rinsing - I just implemented a 3 stage water filter: 25 microns, 1 micron, 0.5 micron carbon block.

I clean using a conventional Vinyl Stack spinner. Then I transfer the stack to a high speed Vinyl Stack spinner, located in a sink. Then I rinse the stack in running water, first with 1 micron water, then 0.5 micron water.

Finally, I remove the stack from the high speed spinner and attach a VS handle, and rotate the stack in a bath of distilled water.

My tap water is very, very pure, and so this works a treat for me. YMMV, especially if your tap water isn't Wet Coast pristine. 

Another convert here.   I have a 10L 40hz tank and a Vinyl Stack 3 LP combo.  My process is:

Spin Clean to remove surface / loose debris and pre clean
Blot
US Clean using Rushton's formula at 35c.  1/3 RPM; 5 revolutions in 15min
Rinse
Nitty Gritty Vac Dry

My findings match most experiences.  Clean LPs often exhibit a noise floor lower than that of my system.  I hear much better transient response, and extreme HF.  I hear much more air and space around musicians.   

My take is that over time, a layer of dirt bonds to the groove surface walls.  This layer is probably only a few microns deep, but it is enough to blunt the leading edges of transients, mask extreme treble extension, and the very low level audio cues that allow us to "hear" space.  This layer is generally impervious to scrubbing.  A US session removes this layer, exposing more of the very subtle modulations deep in the groove.

Regarding surface noise, even previously cleaned LPs exhibited a shhhhh-woooosh sound in the background and between grooves.  After US cleaning, in many cases this sound is gone, and is replaced by silence.

On the other hand, surface damage is now more easily heard probably because the scratches are also cleaned of smoothing junk etc and the rest of the LP is now more quiet.

I have run into an issue where I hear more tics pops as I get closer to the label.  I increased the amount of fluid in the US tank, and more carefully vac clean, which seems to have taken care of the problem.