Croft micro 25 line level valve rolling

[Bourney]

having bought a croft 25/ 7 and finding it a little upfront (Following an EAR 859 and Almarro 318B) I'd like to try to smooth and flesh it out slightly with a bit of rolling, I remembered I have a pair of little used GE5751s. I'm only using the line input. When I pop the lid on the pre how do I know which one is the line valve? Also is there any benefit it changing the valve in the power amp? The valves are the original ones that came with the amp and have a couple of years use on 'em. Any help gratefully received.

[Elephantears]

You are lucky. The GE 5751 is absolutely fantastic in both the 25 and the Series 7; especially good for mid-range projection and clarity. I would put one in the line stage and one in the Series 7. They will reduce the gain by 30 per cent from ECC83s and that might help with the forwardness that you are experiencing. Is this with the Harbeths? In which case the Almarro could never have driven them so anything is going to sound forward!

IIRC the line stage valve is the third from the left in the 25.