The Tube Amp Doctor EF86 / 6267 is a low noise and low microphonic version of the vintage pentode. These tubes were famously used in classic HiFi equipment and microphone preamps. The original Vox® AC15 circuit also used an EF86 and now, thanks to its recent availability, there are plenty of options for guitar amplifiers utilizing this unique tube. The TAD EF86 / 6267 meets all of the standards of the Tube Amp Doctor Premium Selection process. This tube has a rugged construction featuring an aesthetically pleasing perforated shield. The TAD EF86 / 6267 will work in and EF86 or 6267 position.