EL 34 question

I have a VAC PA 35.35 EL 34 push-pull amp, that has had factory upgrades. I was quite happy with it, until I started using a modified SET 300B amp, which has blown the VAC completely out of the water.

I am actually giving thought to selling it, but decided to see if tube rolling might bring it closer in performance to the SET amp.

I have two sets of output tubes that are used, a matched quad of reissue Genelex KT 77, and a matched quad of reissued Mullard EL 34's.

The small tubes are NOS Telefunken 12AU7 and 12AT7, all aound three years in use.

I'm just hoping I can get some insight as to whether better performance can be gleaned from this old amp.

My experience with tubes is recent, lots I don't know, so any old salts that care to help with suggestions would be great.

By the way, the speakers are 94db sensitive custom Tannoy HPD's.

Best regards,
Dan