JBL Synthesis S400

Hoping someone can tell me about this things origins. I have had it for a while and it works and sounds nice. It was originally used by JBL as the sub amp in a Synthesis THX HT system, but is definitely a full range amp as it is rated 10-70khz. I use it as my main 2ch amp.

The internet has questions about who made these and it really varies on the model but the consensus is ATI. This particular model really looks to be a Parasound build. It is so incredibly similar to the HCA units of the day, especially the 1200mkii. Same chassis rails between the amp boards and PS section with the wires zip tied on the same way, same white box caps Para often used for the PS, same heat sinks including on the rectifier, same torroid, same little white and yellow film caps. The differences are minor. It appears the amp board circuitry is simpler than the Parasound models, different PCB material, the way wires connect to the amp boards, etc.

So I guess what I’m wondering is can someone confirm (the obvious) that this is a Parasound build / design? And any chance John Curl had his hand in it if it was?

I’m considering recapping, it and maybe some mods if anyone knows anything about it.
 
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Here are some gut shots of a JBL S400
 
I never did learn much more on this amp, other than I still own it and it sounds great. Massive sound stage, very full, powerful presentation. Smooth, clean.

I would still love to know if this is a John Curl design or adaptation of, so I am bumping this thread hoping Mr. Curl happens upon it, to share any light on this.