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 harmonics, 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.)


Design by: Susan Parker, MIET.

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

N.B. Personal liability disclaimer applies.


Email: susan@audiophonics.com

All design and other information, drawings and images on this website are
Copyright 1992-2010 Susan Parker MIET (unless otherwise credited).

These designs and other information may be used to construct systems specifically for personal NON commercial use only.

N.B. Personal liability disclaimer applies - see T&C.