The more I dig the more Im getting a bit confused. STRs or GC ? Its for a Vibrolux, has room for the longer bottles. Looking into Tungsols ,tried JJs before. Musicians Friend sells Tung Sol 6l6STR with a option of soft,medium ,hard plate current for 'breakup'. Where other online sellers just sell the tubes without this option.. For Fender Vibrolux I like headroom since any drive I would get from OD pedals.