It's certainly very strange that mine have the 4.7uf cap and yours has 12uf. TBH the XR style X-O is a doddle to work on although I will say Marco that your X-O does away with several layers of connectors and unnecessary components compared to the 15XR X-O. My 15's were originally bought for the "REAL" sound project that has been championed by Jeff Day https://jeffsplace.positive-feedback...o-jeffs-place/ he's a real Duelund fan. I've bought a few Duelund components and modded my 15's. I must say that they do sound quite nice. I'd probably at some point try a pair of Duelund bypass caps. Something like this https://www.hificollective.co.uk/com...er-600vdc.html or https://www.hificollective.co.uk/com...ag-600vdc.html these would complete my "REAL" sound experiment. In fact I might order a pair just for the hell of it and see how they sound.