The 27 nF value can substitute without any problem the 22nF values used in these amplifiers, being both the 27nF than the 22nF at 10% tolerance, the 27 can vary down to 24nF and the 22 can go up to 24nf too. anyway, even increasing the value of 5 nF you should will have a very SLIGHT extension on the bass response, (around, 0,2 dB) but I don't think you'll never hear it (may be you can hear it with an oscilloscope.), but sure you'll hear to a good sound!
