lm386 alternatives with same pinout

Started by rhinson, April 04, 2004, 01:58:02 PM

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rhinson

hello there,  does anyone know of other low voltage power audio chips chips similar to the lm386 that would be a plug in replacement---suitable for circuits like the smash drive, runoff groove grace overdrive, etc.? just curious if there are chips that are more hi-end, better specs, etc.  thanks very much.    rh

smoguzbenjamin

Wy would you want to replace the 386? It's worked fine for me. Or is the chip hard to get in your area?
I don't like Holland. Nobody has the transistors I want.

Ansil

theres the nte version of it.. not sure on the no. though..

llike 823 or somehtign


fi you want a dual version of the lm386 there is a similar chip out there

ExpAnonColin

It's more of a unique chip, but there is the national (LM) model and the Japan Radio Co model (NJM).  There's also the LM386-1 and the LM386-3, 3 having better stats I believe, just check the datasheet.

-Colin

rhinson

hello there, yeah the lm386 works fine, but i was just wondering about alternatives in the spirit of experimentation---the same way that a 4558 works fine but it sure is cool to try a opa2134 or try dave barber's idea about chip stacking.  i know this is a power amp chip but i was just wondering about any hi end alternatives.   thanks   rh

smoguzbenjamin

On that note I'll go along with Colin. Try the different 386 n-versions and see what happens. Usually the n-3 is the best one but I can't get the goddarn things here, just n-1. But that works for me. :) See what you can find!
I don't like Holland. Nobody has the transistors I want.

Peter Snowberg

After using the JRC386BD, I'll never go back to the LM386-anything. :D

Take care,
-Peter
Eschew paradigm obfuscation

rhinson

hey peter,  i have a tube of 10 jrc386d's.  what would be the difference between the "bd" and the "d" versions?   thanks.     rh

Peter Snowberg

The "D" in the suffix just means DIP package and the 386B is the 18V version.... roughly the same as the LM386-4, but I like the distortion it gives a bit better than the LM part. The regular JRC386 is more like a LM386-3 (12V max).

Take care,
-Peter
Eschew paradigm obfuscation

ExpAnonColin

Quote from: rhinson.. or try dave barber's idea about chip stacking.

That would be interesting to try with 386's.  Who's up for it, I'm out of them at the moment.

-Colin

Peter Snowberg

Quote from: anonymousexperimentalist
Quote from: rhinson.. or try dave barber's idea about chip stacking.

That would be interesting to try with 386's.  Who's up for it, I'm out of them at the moment.

-Colin
I think in this case you're much better off using the 386 to drive a standard complementary pair of power transistors to increase output. Opamp apps are a little different because the feedback loop is external and you don't have loading resistors on the inputs that are integrated into the opamp.

Try connecting the output to a TIP31 / TIP32 pair through a 470 ohm resistor, using the negative input on the 386, and applying global feedback from the junction of the transistors to the 386 negative input too. You'll need a separate preamp stage. Use a resistor between the pre and the 386 neg. input of about 1/10th the global feedback resistor value (or less) and use a good sized cap (470 or 1000uF) to couple the output.

Hmmm... maybe I'll post a schematic later this week with a little more complex bias arrangement on the TIP pair.  :twisted:

Have fun,
-Peter
Eschew paradigm obfuscation

Mark Hammer

There are a bazillion 8-pin dips that can serve as power-amps.  What is special about them is that they behave themselves when feeding a very low impedance load.  Tell your 741 or 4558 to feed an 8 or 2-ohm load and it will not respond politely.  Tell a 386 or a 5532/34 or an 833 to do so, and they will.

The suffix on the 386 has nothing to do with quality.  Rather, it is an indicator of how much power they can safely dissipate unassisted.  The 386-4 is comfortable dissipating 700mw.  The -1 and -3 crap out at lower output levels.  Of course if you have a way of sinking the heat generated, you should be able to push the lower-suffix models a little further, not unlike being able to overclock a CPU if your cooling system is more effective.

Of course one of the things about power-amp chips used in battery-powered applications is how much quiescent current they require.  A good one will ask for little current until you slam the strings.  I've been used an NJM/JRC2073 that I pulled from some cheap computer speakers and it rocks.  Long, long battery life and mucho loudness.  The 2073, like many of the low-power chips intended for portable stereo device applications, is configurable as a pair of mono devices, or as a single BTL (brideged-mode) channel with more power.