LM386N-4 Question

[ponce]

Would using LM386N-4 (which can run on up to 18V) , increase volume/gain of my amp also when powered by a 9V battery through 3W 8Ohm speaker, instead of LM386N-1?

[Mark Hammer]

No.  The dash-4 suffix refers to the power or heat dissipation rating of the chip.  That is, how much output power the chip can be persuaded to deliver, without any heat-sinking.  You can certainly TRY running a 386-1 at a higher  supply voltage into a lower-impedance speaker load, but it won't be able to manage delivering the amount of current required to deliver 1W before it goes poof and lets out the magic blue smoke.

The higher ratings are for chips that declare "Don't worry, I've got this".  Now higher output power CAN produce greater volume.  But in the grand scheme of things you'll get a bigger boost in sound level by:
- using 12V (8 AA cells)
- using a more efficient speaker
- using a more efficient cab with greater internal volume

[PRR]

I don't think the -4 even means improved dissipation. Just higher maximum voltage. If you are not pushing past 12V, the -N is pointless.

There are "bigger" chips.

+1 to the idea of a bigger lighter air-slapper (speaker cone). A half-Watt in a good Full Stack will annoy the neighbors.

[ponce]

Thanks! That makes it all clear now. Unfortunately, there is no space to add a bigger speaker and/or cabinet because its a guitar build with onboard LM386 amp.

https://www.youtube.com/watch?v=NJsF064YoGE

I like the way it sounds but wouldn't mind getting more fuzzy/overdriven sounds out of it. I've tried addind clipping diodes to the circuit but it seems to burn the IC. How could I modify the circuit to get more dirt? Heres the circuit, but without the .01uf cap on pin 3:

https://sites.google.com/site/thediyprojecthub/home/creator-projects/lm386-audio-amplifier-circuit

[antonis]

I've tried addind clipping diodes to the circuit but it seems to burn the IC.

If you've placed them between pin 5 and GND without a current limiting resistor you've practically short-circuited amp's output.. 

How could I modify the circuit to get more dirt?

Depends on what kind of dirt you want...

Try with a pot in gain control...

[ponce]

I have a 10uF capacitor and a trimmer between 1 and 8 already. Anything fuzzy or a tube sound drive would be cool 

[Mark Hammer]

There is a fixed resistance between pins 1 and 8 inside the chip already.  Placing anything else between 1 and 8 simply provides an easier path for the signal, and greater amplification.  So, one could provide two or more parallel paths between pins 1 and 8 to shape the tone, albeit with some limitations.  For instance, a 10uf cap in series with 470R would provide some full-range boost.  Stick a .047uf cap in parallel with that (no resistance in series with that cap) and you add even more boost to higher frequencies.

[ponce]

How about a voltage transformer to 12V or additonal transistor gain stage/buffer like in a Big daddy/Grace circuit?

[ponce]

I can also get som cool spitty fuzz sounds just before the battery dies. Tried to simulate this with a pot, but it didn't work. It just cuts off abruptly.

[antonis]

What's pot value and how you've wired it..??

[ponce]

I think it was a 10 kOhm liear pot, wired to regulate voltage from the battery, no additional components.

[antonis]

You could wire it in 2 ways:

As a variable resistor (one lug to + of battery and middle lug to + of circuit)

As a voltage divider (upper lug to + of battery, middle lug to + of circuit and lower lug in series with a 2k2 - 15k resistor to GND) to avoid battery overloading when voltage sag turned all the way down..

[ponce]

Seems like It was wired as a variable resistor. What would you recommend to get that dead bat sim - pot valute and wiring?

[antonis]

I'm not sure if you can obtain that with an audio amp..

[tubegeek]

A half-Watt in a good Full Stack will annoy the neighbors.

Since when do you have neighbors?