Is your Telefunken VF14 tube inside your u47 or U48 non-working, microphonic, or worse, been replaced by a Nuvistor? If so, our repair and restoration services can provide a direct replacement for the original VF14 tube with the VF14ER replacement tube. The VF14ER will fit directly inside the VF14 tube socket and will require no changes to the power supply or amplifier circuit. The VF14ER was developed by Andreas Grosser for repair and replacement in original Neumann U47´s. Please contact us directly for a quote.