Difference between revisions of "AudioAmp380"

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* [https://www.ti.com/lit/ds/symlink/ne5534.pdf ] Pre-amplifier
 
* [https://www.ti.com/lit/ds/symlink/ne5534.pdf ] Pre-amplifier
 
* [https://www.ti.com/lit/ds/symlink/lm380.pdf LM380] 2.5W Audio Power Amplifier
 
* [https://www.ti.com/lit/ds/symlink/lm380.pdf LM380] 2.5W Audio Power Amplifier
* 12V nominal
+
* 12V nominal power
 
** 10-22V
 
** 10-22V
 
* Fits into 80x50x20mm extruded aluminum enclosure
 
* Fits into 80x50x20mm extruded aluminum enclosure

Revision as of 17:53, 24 October 2021

AudioAmp380-3D.png

Design

  • Pre-amp plus power amp
  • 50 Ohm input impedance
  • Gain trimmer potentiometer on preamp
  • External mount gain potentiometer
  • [1] Pre-amplifier
  • LM380 2.5W Audio Power Amplifier
  • 12V nominal power
    • 10-22V
  • Fits into 80x50x20mm extruded aluminum enclosure

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Pre-Amplifier (NE5534)

  • Low-Noise Operational Amplifiers
  • Equivalent Input Noise Voltage 3.5 nV/√Hz Typ
  • Unity-Gain Bandwidth 10 MHz Typ
  • Common-Mode Rejection Ratio 100 dB Typ
  • Wide Supply-Voltage Range ±3 V to ±20 V
  • Used as single supply

Audio Power Amplifier (LM380)

  • Wide Supply Voltage Range: 10V-22V
  • Low Quiescent Power Drain: 0.13W (VS= 18V)
  • Voltage Gain Fixed at 50 (34 dB)
  • High Peak Current Capability: 1.3A
  • Input Referenced to GND
  • High Input Impedance: 150kΩ
  • Low Distortion
  • Quiescent Output Voltage is at One-Half of the Supply Voltage

Controls

  • RV1 - trade-off book gain/bandwidth - Tune for best sound
  • RV2 - volume control (after preamp and before LM380 Amp. 1x5 header wired to external pot
  • J1 - Audio In, 50 Ohms input impedance
  • J2 - Audio Out, 8 Ohm speakers
  • J3 - Power, 10V-22VDC

Rev 2 Schematic

AudioAmp380-Schematic.png

Rev 1 Rework

  • Issues
    • Front end opamp has + and - reversed
    • Also hooked up the feedback to the wrong input
  • Replace R1 with jumper
  • Replace C9 with jumper
  • Remove C2
  • 5 Cuts
    • 4 on front
    • 1 on back
  • 5 jumper segments on back
    • 2 nodes

U2-2 3 Rev1 Rev2 Cuts Jumpers.png

AudioAmp380 Back Jumpers.PNG

Videos

ZL2CTM Schematic.PNG

Assembly Sheet

LM380 Rev 1 Assembly Sheet