Zeus MOSFET SE Preamp & PP Power Amp System Test

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Test Configuration

Zeus System Test with 4:1 Output Transformer: 1 kHz THD at 4.1 Vac RMS into 8 ohms = 0.0079%

Test bench with hardware.

SOURCE	PREAMPLIFIER	POWER AMPLIFIER	LOAD	MEASUREMENTS
PC + EMu 1212M (Balanced Output) WINaudioMLS Generator(s)			8 ohm	PC + EMu 1212M (balanced input) WINaudioMLS 1M point FFT + HP8903B
	STW34NB20 mosfet V+ 37 volt supply Rterm: 220K Bias: 400 mA Input Transformer: TX-102 +6dB Output TX: 1:1; 10.5 ohms	2 x STW34NB20 mosfet V+ 34 volt supply Rterm: 120K Bias: 750 mA per mosfet Input TX: 1:10; 600 ohms Output TX: 4:1 or 2:1

Test Configuration.

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4:1 Output Transformer

2.1 watts = 4.09 volts into 8 ohms - 1 kHz FFT (-6dB) - 0.0079% THD

1.1 watts = 2.89 volts into 8 ohms - 1 kHz FFT (-9dB) - 0.0054% THD

0.5 watts = 2.05 volts AC RMS 8 ohms - 1 kHz FFT (-12dB) - 0.0042% THD

0.2 watts = 1.45 volts AC RMS into 8 ohms - 1 kHz FFT (-15dB) - 0.0030% THD

0.1 watts = 1.03 volts AC RMS into 8 ohms - 1 kHz FFT (-18dB) - 0.0028% THD

MUTE = 0 volts into 8 ohms - noise, 50 Hz and harmonics, and computer / monitor PSU >30 kHz pickup - FFT

2:1 Output Transformer

2.1 watts = 4.10 volts into 8 ohms - 1 kHz FFT (-6dB) - 0.018% THD

1.1 watts = 2.90 volts into 8 ohms - 1 kHz FFT (-9dB) - 0.011% THD

0.5 watts = 2.06 volts AC RMS 8 ohms - 1 kHz FFT (-12dB) - 0.0076% THD

0.2 watts = 1.45 volts AC RMS into 8 ohms - 1 kHz FFT (-15dB) - 0.0055% THD

watts = 1.03 volts AC RMS into 8 ohms - 1 kHz FFT (-19dB) - 0.0051% THD

TPA6120 + Power Amp only @ 2 watts, 4.1 volts into 8 ohms
Noise, 50 Hz and harmonics, and computer / monitor PSU >30 kHz pickup - FFT