Excellent point!  I love an inky black noise floor too.  High sensitivity speakers can be difficult in that regard.  If there’s a weak link, you will hear it!  If anyone turns up their volume without a source playing, and puts their ear close to the speaker, you want to hear silence.  If you don’t, it’s a caution flag and time to do some experimenting to try to make it quiet(er).  Could be electrical, grounding, EMI, cables (even HDMI!), amps, etc.  Balanced cables are generally recommended.  Class D used to have noise issues early on, but current offerings from Hypex and Purifi have outstanding S/N and THD.  Not all amp manufacturers that utilize Hypex and Purifi modules are equal either.  I like Buckeye Amps, but there are others.  I’m not saying Class D is the “right” choice over A/B and tubes by any means, but the current stuff are worthy options IMHO.

I have used class d amps on my Klipschorns and they do a decent job but I didn’t like the background hiss between tracks 

Looking at the weight of the ak-7 Klipschorns @ 250 lbs per speaker, does anyone know if that weight is for speaker only or speaker packed and boxed for shipping.   

If you back off the nuts and remove the jumper plate you can then retighten the nuts and they screw down further because of the clearance gained removing the jumper. Then you can pull the plugs out with your fingernails and reinstall the jumper. I know this is late but maybe it will help someone. 

@JJkizak 15???  Gonna slay.            

Are they still for sale, the Xf-48?

It would work fine.

The kits are an exciting prospect.  Taking AL5’s to AL6 by a factory kit would be amazing.  However, considering the price of AL6’s ($14,998 passive; 18,495 active), some back-of-an-envelope math suggests the kits won’t be cheap, even with “just” the passive xo option.

One modest wattage six channel Class D would be fine since these speakers are high sensitivity.  However, I completely understand the lure of tubes for the mids and highs.

Very helpful response. Now I get it. Thanks very much. Makes complete sense to have tubes for the mid-range, and probably where I would go given your info. I always forget about class D for some reason. That might be a more affordable option as well. Thanks again.