The trusty old LM386 audio amplifier from the 70's is still used a lot in low power and portable equipment. Recently some ultra high gain circuits have been recommended that I wanted to simulate with Spice. I started with the datasheet examples for checking the quality of the model. The result was surprising.
In the data sheet one can find a minimum parts circuit, a high gain circuit, and a bass boost circuit:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVSSQp3YrL_JZ1fGa-6knqGnei_UaI4iwbNkKBOhjrulvUP0rHF-c985ALIP_v7nPHdULnY12liCAuIUmQxly5bCGFE6slmVF4ZEq9cDEjKpnmeiA1JNrQmjUEih6Be5f4IgNA_8xick/s1600/lm386-20.gif) | ![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiq6m3wAdhL7iewgiMxJ-T3JgIcPH-1ywtd87gjhB5Sw5Bdfx2gOpPnRR88HEpvkNiGqb4Vd4PQst8QZ_-rkgKV5HoeQ4Wgy8STZiNvihcVbO8wg-o4DA4bPeSlx4FR0IeAGyaNvvtcY4E/s1600/lm386-200.gif) | ![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhP7jy2pvBuq59bHZzJaa1xVZyCEPcc7g4AOV6uR_geHfsky5PoMegU_wioKKmA7Tk1sTyUF8ij4ZfB2f7DDuTbUN7jqLxi2T4vFct-9ECHubFTJEao4QfT-B71BlZStzMa4ziw91d-BBY/s1600/lm386-bass-boost.gif) |
Gain = 20 (26 dB), minimum parts
| Gain = 200 (46 dB) |
Bass Boost
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