I have an MLA-2500 with soft tubes. Seeking information on modification using a pair of 4cx800 tubes in grounded grid.thus eliminating a seperate bias supply and screen supply. Mel Gossard (K3ML) -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com