if I buy an ultrasonic cleaner for my records will I be able to hear the difference?

@rrm , IMHO @pbnaudio gives you a great recommendation. I used a VPI 16.5 for years, used it with most of the available fluids and brushes available and it was pretty good. I was a beta tester for AudioIntelligent, but my fav was the Walker Audio Prelude which took 4 steps, a bit of a pain in the a**. Then after checking out a few friends US machines and having champagne taste & beer budget,  I followed suit following the methodology eloquently described by @rushton in this thread: 
https://forum.audiogon.com/discussions/rushton-s-diy-approach-to-ultrasonic-record-cleaning-published-by-posit 
and here:
https://positive-feedback.com/audio-discourse/rushton-paul-diy-approach-ultrasonic-cleaning-lps/
Long story short; ebay US tank, Vinylstack record spinner to rotate LPs in the tank, a combo of suggested chemicals (a complex first purchase that will last most years), a cheap pump/filter setup to keep the tank clean for ~50-60 LPs without changing water/chemicals and a DIY vacuum rinse station that I made from a $5 Ikea lazy susan. Details of that easy project is in my posts on Rushton's thread. All in ~$500,
It works great, is easy to do(not as simple as a one-button $3k machine), and clearly improves sonics both on old & new LPs. Crap in newly purchased albums isn't to be underestimated. It wears on styli and cantilevers and they should always be cleaned before playing if you want to preserve your gear and get the best sound for your investment. Cheers,
Spencer

I have a V-8. I'm not sure I heard a difference at first between that and my VPI 16.5. I was just using distilled water, photoflo, and isopropyl alcohol, as suggested by the seller of the V-8. Then I tried the "suggested chemicals" that is in Rushton's thread. I think that led to a noticeable improvement in detail and clarity. The chemicals are a blend of tergitol (Triton X-100), hepastat, and isopropyl alcohol. Works great!

I own the V-8 and it certainly does improve the sound of records. It opens them up considerably. But as I've posted elsewhere, the GEM Dandy Record Cleaner did a considerably better job for a far more significant drop in price. For older and damaged records, I found the Groove Lube to very helpful at reducing the sonic effects of the damage. It does leave some residue on the stylus that can easily be removed, but you have to carefully follow instructions and use as little of the Groove Lube as possible and buff the record carefully after spraying on the pads, rubbing them and applying the treatment. 

+1 pbnaudio
i have the same set up. It’s made 40 year old lps, that I took great care of from day one, come to life. Who knew what micro dirt could take out of the music?
amazing
flea market records can still disappoint, but not nearly as often. Makes taking a chance on a $5 copy of Europe ‘72 a good gamble. 
Takes a bit of work to do it right but you only need to do it to disk once. And a good anti-static brush is all you’ll need.  
You’ll find an excellent formula for the bath here on Audiogon, Audiokarma or several other sources. It takes a bit more than just distilled water to get it right. Go for it.

I've heard of "clubs" forming to purchase and share the high end cleaners.  You pool your money, purchase the unit, and each "member" uses it for a week/month then sends it to the next person.