With a properly serviced amp; upgrading tubes, speakers and other components can improve tone quality. There are also preferred circuits that can be referenced to "back date" your amplifier and popular non-factory circuit changes to customize the function and tone of your amplifier.

Previous changes can be re-done to return your amp to stock.  

Good candidates for upgrades include:    

  •   Marshall -Most tube amps, current and  vintage    
  •   Vintage Fender    
  •   Fender Hot Rod Series, Blues series and re-issues    
  •   Mesa bias control  

The controls of a fully buffered effects loop built for a Twin Reverb.