My Laney GH50L sounds boxy with new valves, bias issue or?

[T-e-r-r-y]

I blew a power amp valve a fortnight ago and left my amp into the shop to get sorted. It was returned to me with a set of "Tube Doctor" el34s. The amp sounds really boxy and middley through my Mesa compact 2x12.

Is there something wrong with it? I'm a tube noob (bassist) so any help is much appreciated.

Cheers lads

 

[Dabo Fett]

did it have 6l6's before? when i had my gh50l thats what i had in it, if they changed it over the el34's its going to sound pretty different

 

[T-e-r-r-y]

Mine came stock with el34's, this is the first time it's been revalved.

 

[Underworld]

Your tubes are probably brand new, so they need some time to get burned in. Give them a hard play for 24 hours and they will probably sound better.