For those of you owning ACA DIY amps, there is really only one best sounding 10 uF cap to use as a replacement / upgrade, on the input to the circuit. That is, IMHO, a DYNAMICAP 10 uF " E " type film cap , available from Michael Percy at $87.95 each.
Any other choice will be a waste of your money, time, and life, VS the cost / performance of that ONE 10 uF value cap. Could I be any clearer ??? No substitutions...... except DynamiCap 10 uF "E ".
Their three best-sounding cap uF values by the way are their 0.033 uF, 4 uF and their 10 uF. Unbeatable !!
Jeff