Output Caps For Dehavilland Ultraverve

Some 100 hours gets you most of the way. 

What amp is being paired with this preamp and do know the input impedance of the amp? 

I'm currently switching back and forth between two amps depending on my state of audiophile neurosis at the particular moment.  One is a pair of DeHavilland 50A tube mono blocks with an input impedance of 100K, the other a Clayton 100S solid state amp with an input impedance of 47K.  Occasionally, when I'm feeling nostalgic,  I'll pull out my old BEL1001 solid state amp which I used for about 25 years and listen to that for a short while.  That has an input impedance of 27K.  I'm guessing that you were going to recommend a lower value cap, which would be less expensive and smaller, if I was only driving a high input impedance amp, but I would like the option of being able to drive a solid state amp as well, so the 2.2uf is probably the best bet.  Also, at some point I may move the amp(s) closer to the speakers and use a longer interconnect.  I'm not sure if the larger cap value would be advantageous for that or not...

Correct. You get a gold star! Keep to total capacitance at 2.2uf to 2.8uf or so.  

Ah, but am I correct about the higher total capacitance driving longer cable runs better?  I believe a gold star is in order only if both of my assumptions were true...