Stereo 20
	Long-Tailed-Pair Distortion
	(LTP driven direct from oscillator, output into 242kOhm load)
	Some power supply filtering added to minimise PSU hum & noise.
		ECC83, Phillips Miniwatt, Dual Triode
	Output	THD and Noise, %
	Volt-peak, into 242kOhm	Triode Section #1	Triode Section #2
	2 Vpeak	-	-
	5 Vpeak	0.05%	0.05%
	11 Vpeak (=9 Watts Output)	0.12%	0.12%
	20 Vpeak	0.45%	0.40%
	30 Vpeak	1.00%	1.00%
	40 Vpeak	1.90%	1.90%
		ECC83, AWV Radiotron, Dual Triode
	Output	THD and Noise, %
	Volt-peak, into 242kOhm	Triode Section #1	Triode Section #2
	2 Vpeak	-	-
	5 Vpeak	0.05%	0.05%
	11 Vpeak (=9Watts Output)	0.12%	0.11%
	20 Vpeak	0.38%	0.38%
	30 Vpeak	0.95%	0.95%
	40 Vpeak	1.90%	1.90%
	Stereo 20, Overall Distortion
	LTP driven from oscillator, output into 15 Ohm resistive load
	Left Channel	THD and Noise, %
	NEC 6BQ5's
	9 Watts Average, Open Loop	0.80%	Corresponds to 11 Volts-peak output from driver
	9 Watts Average, Closed Loop	0.05%
	Right Channel	THD and Noise, %
	AWA Radiotron 6BQ5's
	9 Watts Average, Open Loop	1.30%	Corresponds to 11 Volts-peak output from driver
	9 Watts Average, Closed Loop	0.11%
	TL/10
	Long-Tailed-Pair Distortion
	(LTP driven direct from oscillator, output into 242kOhm load)
	Some power supply filtering added to minimise PSU hum & noise.
		6SN7, Super Radiotron (Aust), Dual Triode
	Output	THD and Noise, %
	Volt-peak, into 242kOhm	Triode Section #1	Triode Section #2
	5 Vpeak	0.07%	0.10%
	10 Vpeak	0.08%	0.15%
	20 Vpeak	0.16%	0.30%
		6SN7, RCA (USA), Dual Triode
	Output	THD and Noise, %
	Volt-peak, into 242kOhm	Triode Section #1	Triode Section #2
	5 Vpeak	0.15%	0.12%
	10 Vpeak	0.22%	0.17%
	20 Vpeak	0.35%	0.50%
	TL/12
	Long-Tailed-Pair Distortion
	(LTP driven direct from oscillator, output into 242kOhm load)
	Heavy power supply filtering added to minimise PSU hum & noise.
		6SN7-GTA, Super Radiotron (Aust.), Dual Triode
	Output	THD and Noise, %
	Volt-peak, into 242kOhm	Triode Section #1	Triode Section #2
	10 Vpeak	0.10%	-
	20 Vpeak	0.14%	-
	30 Vpeak	0.15%	-
	35 Vpeak (=approx 10 Watts)	0.17%	-
		6SN7-GT, RCA (USA), Dual Triode
	Output	THD and Noise, %
	Volt-peak, into 242kOhm	Triode Section #1	Triode Section #2
	5 Vpeak	0.10%	-
	10 Vpeak	0.12%	-
	20 Vpeak	0.16%	-
	30 Vpeak	0.22%	-
	35 Vpeak (=approx 10 Watts)	0.32%	-
	50 Vpeak	0.40%	-
	TL/12 Output Stage and Driver/Input-Stage Distortion
	Complete amp (EF37A, 6SN7, 2xKT66) measured, output into 15 Ohm resistive load
	Power Out	THD and Noise, %
	12 Watts Average, Open Loop	1.50%
	12 Watts Average, Closed Loop	0.10%
	* All THD measurements at 1kHz, and filtered below 250Hz to reject power supply ripple.
	S.Spicer, May 2002.