Hello again everyone,
Well, I have spent an interesting and educational day working on the Luxman again.
As I described above I had found the the L430 seemed very bass heavy following the recap, especially before it had adequately warmed up (which it never did before). I spent some time this morning and afternoon listening closely to the system using music that I knew well and was very familiar with. I found that in fact, although the bass settled down a bit after warm up, the bass was still a lot 'fatter' and punchier than it had used to be. Once warmed up it lost the kind of booming character that I had particularly noticed, but the bottom end of the music was definitely 'unbalanced'. There was more bass, even though it still sounded pretty great, but something was clearly not right. The amp had never sounded like that previously.
I asked above if the big new Filter Caps might have had anything to do with it. Although they are only slightly bigger, 18,000uF vs 15,000uF, I wondered if that might mean that the amps ability to deliver big bass transients might be affected, so that the bass ended up being 'bigger' and a bit unbalanced to the rest of the music??? (No doubt this is a load of rubbish, but I don't quite understand just what was going on, or why)
@CohibaJoe suggested above that I go back to the original Nichicons, but I wasn't keen on that as they are 34 years old. It just so happened though that when I ordered my parts from Mouser I also ordered some 15,000uF/80V parts that were also the same physical size as the old Nichicons. These were Cornell Dubilier 383LX153M080N082 15,000uF 80V parts. So I was still going up slightly in voltage and temperature grade, but the capacity matched the original Luxman spec.
So, I decided that I had nothing to lose by trying out the Cornell Dubilier caps and just see what happened.
Here is the L430 back on my work table with the Nippon Chemi-Con parts in place.
One of them removed.
Here is one of the Cornell Dubilier caps mounted, with the other upside down so you can see the pins.
These are 4 pin caps, but they also have a lead pitch of 22mm whereas the original Nichicons were 25mm. This is where the Luxman excels as it has mountings that will also support both the 25mm and the 22mm lead pitch.
Here are the Cornell Dubilier caps both in place. At this point I only soldered the positive and negative pins so I could test it.
If you look carefully, compared to the Nippon Chemi-Con caps, these are rotated slightly left. This is how they can fit into the alternative set of mounting holes.
Here it is under test. Hands kept well away!
Well, I have to say I was really astonished. The Luxman sounded exactly like it should, only better. The over emphasized bottom end was gone, but it retained plenty of punch on big transients. The music sounded far more balanced, and there was no discernible difference between cold and warmed up, which is what the amp had always been like.
Obviously even the slight increase in capacity of those Filter Caps buggered up Luxman's tonal design. I was frankly surprised. I had imagined that the extra capacity would just offer the amp some extra headroom, but it sounds like it actually made use of the additional power when processing transients.
I'm pleased with it now. I thought it sounded great before, once I finished the recap, but having lived with it for a few days I came to realize it was as though the loudness button was on all the time. It is now like I think it should be.
I have now soldered all the pins on the Cornell Dubilier caps and reassembled the machine. Normal service resumed? Now for the Elna's to do their thing. Time will tell.
Thanks to everyone who has commented on this thread,
Trevor
Gotta go. I'll pm ya. 
