More wattage

[whomeno]

I have built the nosiy cricket from here http://tagboardeffects.blogspot.com/2012/04/noisy-cricket-mkii.html
works good. sounds great for a 0.6 watt amp.
My question is this, how could I make this a 1 watt amp?
Thanks

[willienillie]

Build another one?

[Rob Strand]

It depends on what freedom you have with speakers.

Build another one?

Probably easiest.

Also, 2x0.6W into two speakers will be louder than 1.2W into one speaker.

Larger diameter speakers are usually louder but that's not always true.

Strangely enough you can get 1W from an LM386 by using a 16 ohm speaker and increasing the supply voltage.    Changing the supply may or may not change the tone.

Without changing the supply, the solution is bridge connection.  That's not normal connection for an LM386 but people have done it.  You get twice the power but you need twice the impedance in the speaker.   It's not the same thing so the tone might change.

Then there's an LM380.   Again not the same thing but at least it's built for the job.

[anotherjim]

I suspect 1W won't give the significant volume boost you're looking for. If 0.6w isn't loud enough for practice/recording, you either want a more efficient speaker or get a 5w design, but then a pedal power supply probably won't be strong enough.
What are you using for a speaker?
What power supply voltage do you have?

[whomeno]

Running it at 9 volts. using a speaker cabnet with a vintage 30 16 ohm.
Was just woundering on going with more wattage.  more then likely keep it as is

[anotherjim]

I think Rob's answer above pretty much covered it.

16ohm speaker means you can get away with a higher supply voltage. As it is the chip might be fine with 2 similar speakers in parallel for a total 8ohm and using 9v supply.

For any given single power amplifier, you either lower speaker load impedance or raise supply volts for more power, and then check if the power supply can deliver it and that the amp chip can handle the extra heat dissipation.

As for anything else that can increase the power of any given combination of the above, simply running it into clipping is the only way. Then you have square waves, which have average power the same as the peak power.
The amp swings the speaker voltage up or down by 4.5v. The speaker is 16ohm. Power is V²/R = 1.27W. That assumes the supply voltage doesn't sag below 9v, the chip amp has a negligible output impedance and can actually swing the full 4.5v up and down. The last 2 are unavoidably imperfect so it's going to be closer to 1W.
Maximum clean is the RMS of that peak power or x 0.7 for easy sums so that going to be about 0.7w power at best.

The non-linear response of our hearing is such that these small differences in power really are negligible in terms of how loud it seems. A 1dB increase in power is just about audible if listening really critically. To sound twice as loud actually needs more like a x10 power increase.

[whomeno]

I was just looking  at the lm380.
Would it work as a plug in replacement  for the lm386.
I don't  think it would, am I right.

[anotherjim]

The LM380 still won't give more power unless you raise the voltage or lower the speaker impedance.
The LM380 beats the LM386 by being able to handle higher power - it cannot by itself give more power.
Also, LM380 is a 14pin chip!

The bridge amplifier configuration uses 2 chips to drive both ends of the speaker coil. This doubles the voltage swing and therefore doubles the current. Since power is proportional to Volts*amps, the doubling of both gives x4 the power of the single amplifier. This is the most practical way to get higher power if you can't raise the voltage or lower the speaker impedance.

This page shows a scheme for x2 LM386 chips.
http://rombusevilbones.blogspot.com/2014/12/dual-lm386-guitar-power-amplifier.html

[whomeno]

Ok guys
1 more question.
I'm  going to go with thelm386n-4
Which will handle up to 18 volt, should  I add a
Heat sink to it to keep it cool?

[Rob Strand]

I'm  going to go with thelm386n-4
Which will handle up to 18 volt, should  I add a
Heat sink to it to keep it cool?

Watch out how you interpret handling stuff on amplifier chips.  It might handle to voltage but it won't handle that voltage for low impedance loads.   Take a look at the TI datasheet,  then fig 7 (4 ohms), fig 8 (8 ohms), fig 9 (16 ohms).   Unfortunately the TI datasheet has a few bugs and doesn't clearly show the impedances.
http://www.ti.com/lit/ds/symlink/lm386.pdf

If you are using 8 ohms speakers the maximum power out is 0.82W regardless of whether you are running at 12V or 16V.   At 16 V the power dissipation goes up and the device heats up but with no increase in output power.   At 16 ohms you do get more output power at 16V.

For 8 ohms, at 12V  Pdis = 0.82W and at 16V Pdis = 1.43W.

Without thinking too much:  The table in 6.1 show a maximum dissipation at 1.25W over the "free air temperature range".  Then table 6.3 shows the "free air temperature range" as 0 to 70C.    If you free air temperature is only 40C maximum you can dissipate more power.    So overall it looks like 8 ohm + 12V will be fine but 8 ohm + 16V relies on a lower ambient temperature

Going beyond that:  For the Pdip package section 6.4 gives 53.4 degC/W so 1.25W will cause a 67C rise above ambient.  So at 70C ambient the chips internal temperature will be 70+67 = 137C  which is pretty darn hot.

So what that says is some heat sinking will help reliability.      You can heatsink the top of the chip.   Thicker tracks which extend out around the chip will also help.

[MaxPower]

You might want to check out those audio amplifier chips intended for automotive use. I just built an amp using the TDA2005 and initial impression is pretty good.

There are other auto audio chips which are more popular as well.

[MaxPower]

I should add that these chps obviously expect a12-14 volt and 1 amp (or more) power supply. Perfect if you happen to live in a van down by the river. Or you have a12v, 2amp supply.

Btw the tda2005 is capable of 10w + 10w stereo or 20w bridged mono.