There was a 532, but not sure if a 533. The 532 was more of a Levinson traditional design and around $20k. It has some issue and didn't last long.
The "h" series was built in the Crown factory having 2, 3 or 5 channels but using the same chassis. You just ordered it with the number of modules you wanted. There was even a 531h. The 532h ran about $8500.00. This was a great amp and didn't get the appreciation it deserved. This series was not a traditional Levinson design that doubled down etc. With that and being built in a different facility could be the reason. The "h" series used banks of small capacitors opposed to large can size, this gave the amp a very fast lively response. The sound had one of the flattest responses I've heard to my ear. As I mentioned above my current amp is better but there are aspects of the 532h I miss. The "h" series was in the line up for years.
I know you mentioned fatigue but I suspect that was possibly an equipment mismatch somewhere in the chain. I used my 532h for both music and movies, using JBL speakers the sound was never fatiguing to me and I don't especially like bright. I'm sure compared to Boulder the 532h was also outclassed.