Groove Tubes GT-6CA4 - This is also known as an EZ81 rectifier. This is the rectifier used in the Marshall 18 watt amps such as the model 1974, the Vox AC-15, and the 65Amps London.
Groove Tubes GT-6CA4 (code 55082)
Guitar Amplifier Tube, Common 9 Pin Rectifier for Smaller Amps
£19.96 (inc vat)