Have just replaced my DSL5c with new version and i see valve layout has changed. Can i replace the ecc99 with a TAD12bh7a which I still have? Apparently depending on circuit or amp design this can be possible.
Also why the reduction to 2 ecc83's? Your site and Sweetwater both list this new model as having 3 ecc83's! Is my new amp wrong? Is the phase inverter missing?