The Cool Valve ECC803S is the finest twin triode with separate cathodes available in today’s market. Double triode means the valve is built with two totally independent triode systems. The most demanding tube for both sound and build quality is Telefunken ECC 803S. This original tube can only be sourced from old inventories and not reliable sources offering no warranty period. There is the risk of forgeries, functionless valves or overpriced goods. We tried to find a way to make a better product for high requirements of exclusive amplifiers.
EAT has set a high standard by trying all existing ECC 803S by defining sophisticated selection methods to get only the very best to our demanding customers. The selection procedure uses several measurements. All measurements are performed after a long burn-in procedure and thermal stabilization of its parameters. Only a few valves pass the Selection process and even fewer pass the strict Diamond selection.