Zeus MOSFET SE Preamp & PP Power Amp System Test


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)

Zeus SE Preamp Line Driver

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.


4:1 Output Transformer

4.2 watts = 5.78 volts into 8 ohms - 1 kHz FFT (-3dB) - 0.0110% THD

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 harmoics, and computer / monitor PSU >30 kHz pickup - FFT

2:1 Output Transformer

4.2 watts = 5.78 volts into 8 ohms - 1 kHz FFT (-3dB) - 0.032% THD

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

(All tests 24 bit, 192 kHz sampling, 1 million point transforms.)


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Design by: Susan Parker, MIEE.

The information contained here may be used to construct one set of amplifiers specifically for personal NON commercial use only.

N.B. Personal liability disclaimer applies.


This page last modified on: 18th November 2005

All information, drawings and images Copyright 1995 - 2005 Susan Parker unless otherwise credited.