The architecture of the little gem has been updated with an input buffer as found in the little gem mkii feeding the inverting input and the volume control changed from the output rheostat to the type and placement as shown in the datasheet application notes.
Ruby amp vero layout.
Although they are correct according to the schem.
The ruby amp is an lm386 based guitar amplifier.
Also added a very small heat sink.
The main power amplifier stage is based on the lm386 audio integrated amplifier.
As you can see in the schematic below there s a lot going on inside that eight pin dip chip.
Ruby is an enhanced version of the little gem battery powered amplifier.
I just built the noisy cricket based on the ruby amp and wired it straight into a strandard 8ohm 8 midrange speaker and it worked just fine.
It is a popular choice for low powered guitar amplifiers due to its low quiescent current and ability to run on 9v.
I have just verified this.
It might be helpful to add a daughter board to the layout.
I was pleasantly surprised about how easy it was to use the software and i may well consider using it again in the future.
I don t think it s too fussy about what you use i ve seen people use the tiny 1 mylar speakers or hook them up to 4 x 12 marshall cabinets.
Verified ish the gain wires need to be switched around.
The 1000uf caps i have a kinda big so the board ended up being 11x6.
I used a demo version of lochmaster to layout a version of the lm386 ruby amp.
The data sheet for all 78xx v r s suggest using two fairly large caps for the in and out to ground.
The lm386 chip amplifier.
The 1 lm386 chip amp does all the amplification in the ruby amp.
Ruby amplifier stripboard layout.
Mains failure alarm stripboard layout june 3 may 2 april 10 march 3 february 5 january 3 2013 27 december 1 november 3 october 1.
I feel it is a little expensive for the full version the demo version is software limited no saving or post editing etc but it was just what.
Maybe overkill but i have made almost every 386 amplifier on the internet.
The main improvements of the ruby amp vs the little gem are new the input buffer a renovated volume control and an updated gain potentiometer.
Simple dual led battery monitor stripboard layout.
The lm386 is a specialized op amp that was designed for easy creation of various audio amplifiers.