Thumbs up for ultrasonic record cleaning

I've been experimenting a fair amount over the past week.  At first, I was running the tank around 40-43 degrees Celsius, for 3 turns @ 7 mins/turn.  So 21 minutes total.  After reading more on the VPI forums, I decided to try Harry's recommendation of no heat (other than cavitation generated)  and increasing the rotation speed.  So I have been doing 10 minutes without heat @ 4.5 mins/rotation.  Really, there's not much perceivable difference.  It's a bit of apples to oranges or I'd say there is no difference.  Although some records are going to need another bath because they still have a fair amount of pops and ticks.  But this was even the case at 21 minutes.  They are probably just beyond cleaning.  What I don't agree with on the other forum thread is the loss of highs.  Even at high heat for 21 minutes, I immediately noticed the opposite - increased upper treble extension.  So maybe my gear isn't quite good enough to notice a loss in highs or maybe it's simply not happening (I suspect the latter).  I think I've cleaned about 80 records so far.  Still a loooong way to go.

@audiom3,

My Vinyl Stack has various settings assigned to various (rpm). I use the 12v setting that is equal to 1 & 1/2 rpm (rotations per minute) for a 30 minute cycle @ 45C.

Again, I do pre-steam.

@audiom3- don’t give up on a record just yet. One thing I learned, aside from the various fiddling you may do with the ultrasonic, is that a good old fashioned cleaning, using something like AIVS No. 15 and rinse will, in combination with US, sometimes take a record from noisy to clean. And it requires multiple cleanings sometimes too. It may not be worth the trouble for some easy to get, fairly cheap record, but if it is rare and valuable, well worth the trouble. I don’t rely exclusively on ultrasonic, but combine traditional cleaning with US and that’s where I’ve found the best results on troublesome records. (No guarantee- record could be permanently damaged, but sometimes, it works and worth the effort in the instances I mentioned).

Wow, thanks guys. 
@slaw  No issues with treble for those longer/warmer sessions?  
@whart   Yeah, I do have a few more valuable records that are very noisy and would love to spend the time to clean them up if it's even possible.  One that I really treasure is an RL/ss (both sides) Led Zeppelin II pressing.  I just don't know how much is groove damage/scratches vs. dirt.  As long as I'm not damaging the record, I don't mind wasting time on it experimenting.

@audiom3,

I haven’t noticed any problems at all. In fact I notice the opposite effect, in this sense... the fact that the lp is cleaner, the stylus can retrieve more info and I mostly notice an increase in transparency, inner detail, w/ better defined/more musical bass. I’ve done 30 minutes/45C for almost as long as I’ve had the cleaner. I have done up to 50 minutes (this is the max recommended time for my cleaner) one time for a extremely nasty gift lp that ended up better than before.

I once left a new lp on a 30min./45C cycle and forgot to turn on the Vinyl Stack. I put it through another cycle and played it. I could not hear any hint of damage.