I got one of these recently from a Webcor extension speaker..now..am I wrong, or should the 12AU7 be a preamp section? seems I need line in power to the input to get any sound out of it.. It probably needs new tubes as well..output is low even for 9 watts...and it breaks up super quick. So far, the caps and resistors have tested within acceptable tolerances. Any ideas or suggestions would be helpful! Thanks!!