Leak TL 12 mono power amplifier 
REPORT ON TESTS OF TWELVE WATT AMPLIFIER Marked: "POINT ONE" TL/12, H. J. LEAK & CO. LTD. TEST CONDlTIONS. In all cases the input was applied to a 50,000 ohm resistor connected to the amplifier by 3 feet of screened cable. The output load was in all cases a resistor of 18 ohms, and the output transformer secondary windings were connected for the " 15 ohms20 ohms" condition. TOTAL HARMONIC DISTORTION for 10 WATTS OUTPUT. 0.037 at 1,000 c/s, (0.0003 ratio to fundamental). HUM AND NOISE. 80db referred to 10 watts. SENSITIVITY. 148mV r.m.s. input gave 12 watts output at 1,000 c/s. LOAD DAMPING FACTOR. (Load impedance/output impedance). 42 for 10 watts output at 1,000 c/s. (Output impedance
0.43 ohms). FREQUENCY RESPONSE. Gain relative to that at 1,000 c/s measured at 7.5 watts output, including the losses introduced at the higher frequencies by the capacitance of the input resistance of 50,000 Ohms.

