Got it, I misread your post. Sorry. It does sound like clipping.
The CLX may be easier to drive than your SL’s. Its also hard to compare your CJ to an OTL amplifier like the MA1.
I ran into a similar situation at one point. I bought a pair of Mac
MK1.2Kw monoblocks, they would not drive my U1’s without clipping.
I guess the Macs couldn’t handle the rising impedance of the SL’s
so I sold them and moved on.