On offer today we have a matched pair of Mullard old shield white print ECC83 .
Using our AVO VCM163 for conditions of or Va = 250 V Vg = -2.0V against a nominal specification of anode current Ia = 1.2 mA and mutual conductance gm = 1.6 mA/V, the following results were obtained:-
Valve C1, A1 Ia = 1.0 mA gm = 1.4 mA/V
Valve C1, A2 Ia = 1.0 mA gm = 1.5 mA/V
Valve C2, A1 Ia = 1.0 mA gm = 1.4 mA/V
Valve C2, A2 Ia = 1.0 mA gm = 1.3 mA/V
As you can appreciate this represents excellent matching of each triode section within each envelope and superb inter valve matching such that this represents and excellent matched pair.