Help needed: Calypso volume variance between standard and Signature.

I just stepped up from the standard Calypso to the Signature version (with different caps and other internal parts). One thing I noticed immediately is that I must set the volume level lower to achieve the same volume I was used to with the standard version. Both standard and Signature are specified for 29db line-level gain for balanced/out. Now the Signature does boast of 4uF coupling capacitors from Dynamicaps, where the standard used 2uF REL caps. One thing I am sure of is that the variance is not attributable to tubes (I've tried different ones).

I like being able to range higher on the scale as a rule. I know this is a minor annoyance, but still.

Can anyone help to explain the variance?

Thanks in advance,

Mark