Hi Martin,
Thank you for your assistance; I'm getting there

Yes, OK I'll switch it over to the 50k impedence setting. I had wondered about this; considering the output from the DAC was probably quite high.Needs a bit more stick on the volume control control though.
The Cap' calculator would suggest a value of around 1.6 uf now. Do you think that would be OK.
Curious - As I have no caps' in place at the moment does that mean my optimal
low frequency response is infinity. The sound is better; vocals have really come alive; more detail and the difference between good and bad recordings seems more noticeble. but does sound less controlled, especially at the bottom end. Hence the caps I guess.
TIA
Tony