These type of units are no substution for cleaning your vinyl records.
Build quality is very good for the era.(1978) Made in USA by a very good company.(at the time) Their other products are still sought after today for their quality & performance. This however is not one of their better ones. Also, keep in mind that this one did not work and was listed as such so it may not be an accurate representative of how it may have been when new. I replaced all of the active IC's with currently available parts (same part numbers) and it now does function however there some parts (MOSFET's) that could not be obtained today or easily substituted with modern counterparts. This fact may be the reason it doesn't perform as well as it may have when new. It does however act on bad (loud) scratches on a record but can't remove low level noise. In conclusion, it's no substitute for cleaning your records which will reduce the overall surface noise when played.
SAE 5000 Impulse Noise Reduction System does what it was made to do and does it very well.
I had one of these when I was in High School and we had a radio station. I was one of the engineers. Back then we had to play vinyl or reel to reel tapes. After several plays, the vinyl records would start to click and pop. This SAE 5000 unit solved the problem and solved it very nicely. Now, getting back into vinyl this unit will provide me with a better listening experience by cleaning up the smooth sound of my vinyl collection.