(!!) (2nd Best Pair) ECC40 Philips NOS made by La Radiotechnique, Chartres/France 1969 (6.1/6.7ma and 6.3/6.9ma) 1-3% matched
(!!) (Best Overall Pair) ECC40 Philips NOS made by La Radiotechnique, Chartres/France 1969 (6.4/6.7ma and 6.5/6.7ma) 1-2% matched
(!!) (Recommended Pair) ECC40 Philips NOS made by La Radiotechnique, Chartres/France 1969 (6.0/6.5ma and 6.1/6.8ma) 1-3% matched
(!!) (Recommended Pair) ECC40 Siemens NOS made by La Radiotechnique, Chartres/France 1967-1972 (6.1/6.4ma and 6.0/6.0ma)
(!!) (Best Pair) ECC40 Philips NOS made by La Radiotechnique, Chartres/France 1969 (6.0/6.1ma and 6.0/6.1ma) 1-2% matched
ECC40 Philips NOS made by La Radiotechnique, Chartres/France 1967-1970