Hello! I've got a simple audio amp design (attached) which gives me the 20 dB boost I'm looking for... until I plug in my 50Ω load. Then the gain drops dramatically. I'm not sure if this is due to a) the load changing the feedback resistance, b) my power supply not being able to give the current I need, or c) something else. Any advice on how to fix this problem would be terrific. Thanks for reading.
Specifics:
- My input signal is a pulse that is high for ~100 μs and then low for ~100 ms (~0.1% duty cycle). The high level could be anywhere from 10s of mV up to a couple V; the low level is zero. The signal will never be negative.
- The circuit gives 20 dB gain up to an output level of 20 V.
- The load is 50 Ω (headphone). Therefore, the load could get up to 400 mA and 8 Wthough for a very short amount of time.
- The power supply is 24/0 V (two 9Vs in series, a 12 V regulator (7812), and a 7660 chip)
Specifics:
- My input signal is a pulse that is high for ~100 μs and then low for ~100 ms (~0.1% duty cycle). The high level could be anywhere from 10s of mV up to a couple V; the low level is zero. The signal will never be negative.
- The circuit gives 20 dB gain up to an output level of 20 V.
- The load is 50 Ω (headphone). Therefore, the load could get up to 400 mA and 8 Wthough for a very short amount of time.
- The power supply is 24/0 V (two 9Vs in series, a 12 V regulator (7812), and a 7660 chip)
Attachments
-
18.4 KB Views: 42