EQD Acapulco Gold: which LM386N can I use?

[Plexi]

Hi there!
I'm starting this loud preamp.


The original one use JRC386

I found here where I live:
LM386N-1
LM386N-3
LM386N-4


Chip Name   Min Voltage   Max Voltage   Minimum Output Power   Typical Output Power   Load Impedance
LM386N-1     4 volts             12 volts                   250 mW                          325 mW                           8 ohms
LM386N-3     4 volts             12 volts                   500 mW                          700 mW                           8 ohms
LM386N-4     5 volts             18 volts                    700 mW                          1000 mW                           32 ohms


I was thinking in use the N-4, and see what happen if I use 18v.

Which is the most appropriate?
Sorry my ignorance.

[bluebunny]

"Appropriate".  I think that's much like "good".     It's likely to be brain-melting whatever you choose.  Go for it and tell us how much it hurts.   

[Plexi]

Sorry for my english
I don't undestand what you mean w/ "appropiate" and "good".

I notice that in OP1 they're producing the gain (linked pin 1 with 10u cap to pin .


I'm very noob about opamps: am I wrong, or you can use this pedal direct to a small speker?
As a some kind of Ruby amp: 1000mW = 1W



Looking around for pedals with LM386, I foun the DAM Sonic Titan, ROG Big Daddy and Grace, Krank Dist. Maximus and Greer Amps Sucker Punch.
Uses a JFET to push the LM386 (instead another LM).
They sounds much more musical, less fuzzy and compressed.

[blackieNYC]

Might not be worth doing 18volts.  That could presumably give you more headroom, but your circuit is certainly not going to allow for headroom, sonically speaking.

[Fndr8875]

I used the radioshack on, i believe its only half a watt. BE CAREFUL...i was shocked how loud this this was. i dont think i even go it to 12 oclcok. I have a solid state amp so obviously it will boost differently than a tube amp. I ended up dismantling it as i had better use for 2 lm386s since my radioshack is now gone and 2 pansonic 1uf films...It was decent dirt , sure if i went to the trouble of adding the pregrain pot mod which gives you volume control itwould have been more useful. God i cant imagine if you had the 1 wat or whatever the most powerful 386 in there..

[Plexi]

Might not be worth doing 18volts.  That could presumably give you more headroom, but your circuit is certainly not going to allow for headroom, sonically speaking.

You're right...
Maybe if it's used as Ruby amp, am I right?

I mean: as power amp, it will sound a bit louder.
But used in any pedal, as Acapulco Gold, I wont.

[Plexi]

I used the radioshack on, i believe its only half a watt. BE CAREFUL...i was shocked how loud this this was. i dont think i even go it to 12 oclcok. I have a solid state amp so obviously it will boost differently than a tube amp. I ended up dismantling it as i had better use for 2 lm386s since my radioshack is now gone and 2 pansonic 1uf films...It was decent dirt , sure if i went to the trouble of adding the pregrain pot mod which gives you volume control itwould have been more useful. God i cant imagine if you had the 1 wat or whatever the most powerful 386 in there..

You're right, that's everyone who have it/built it says.

I guess another good mod is to ad one one resistor, or 1k as variable resistor pot in series with the 10u cap in OP1.
And why not 100/250k as variable res in R2.
If you want massive gain (and noise), I guess you can add a 10u cap from pin 1 to 8 in OP2.

I'm only thinking in loud voice....

[bluebunny]

Sorry for my english
I don't undestand what you mean w/ "appropiate" and "good".

Your english is great, Plexi.  The trouble with "appropriate" and "good" is that they are subjective and not measurable.  Your "good" might be different from my "good"... 

[Plexi]

Now I get it! 

BTW: last night I ordered two LM386N-3 and one LM386N-4 to my supplier.
us$1,05 and 1,25 respectively.
Maybe It'll arrive next week.

Ordered an LF347 too (PlexiTone) 

[Fndr8875]

hope your ears and amp survive the -4 hahah, i double checked and all my 386s are n1. And seriously at like 10 or 11 oclock id say with the volume level on my solid state non master vol amp set on less than 1 the volume was equal to it turned not quite half way, its hard to say i dont play at loud volumes , needless to say it was enough for me to jump,,,i thought vol was turned ll the way down on pedal, the pot i was using was a push on type and so even though it was turned all the way down the knob, the pot actually wasnt. Its hard for me to understand , even in a loud band setting how this pedal could be useful with such a substantial boost. The production one uses the n4.

[anotherjim]

All that Acapulco circuit really needs is padding down at the output. As it stands, it will hit your amps input with at least 8v peak-peak. I'd use a 33k resistor after the 1uF output cap then to a 10k log volume pot. Not sure if it needs R1 there as input of a 386 is looking to 0v anyway, so don't need a bias reference. Put R1 on the input side of the coupling cap instead as anti-pop pull-down.

When not actually driving a speaker and on moderate supply volts like 9v, I doubt there is much to choose between the various 386 editions.