Thanks for your input ... much appreciated.
The phono in question is my own design ... currently with 6n1p/riaa/12BH7/6H30
As noted, I have some issues with white noise, on one channel ... I thought it 'might' be C4S related, but I can see form the kind replies to my original post that this is unlikely.
For all I know the noise issue could be due to a dry joint, or dodgy tube socket ... I am in process of a chassis rebuild anyways, so hope to solve this aspect in the process of the rebuild.
Thanks once again for re-assurance regarding C4S ... I really like the sonic aspect from these devices, by the the way.
Regards
AudioFan