SmokeyAmp - High Gain Mini Amp

[FabGTO01]

Hi,

i've just open my brother's one and its very simple but good sounding and fun mini-amp, specially with a real cab.
I haven't buid it yet so its not verified (it's my first complete vero) and be careful.



Fabrice

[FabGTO01]

Hello,

I've build it, but it works bad.
I have a sound when I play but there are some auto-oscillations and the sound have a lot of treble compared to the original.

Here is the schematic I made. Could someone check if I made mistakes in the schematic or the vero (or both) or if there is a stupid value and wire or bad polarity...



Thanks for your help,
Fabrice

[alltrax74]

I think there is a mistake in the layout, the 47µf on the right should connect the +9v to ground and not IC pin6, it's a filtering cap for the dc power

[Travis]

No that cap should go from pin 7 to ground and there is no filter cap for 9V on the schematics available online.

The 10n input cap isn't shown on schematics online, and that will result in a brighter sound. This circuit does not need an input cap, you can connect the input directly to pin 3

I've breadboarded this based on the commonly available schematics online, and I get the annoying fizzy decay and squealy oscillation stuff as the note dies out. I will have to try again and see if a filter cap on 9V helps. My other thought is that the 10n could possibly connect from pin 3 (input) to ground to tame high frequencies at the input.

What I really suspect is that this is just the classic decay issue that so many of us have had with 386 all along.

[FabGTO01]

Hello,

I made some pictures of the original with all components and the double side PCB.







I hope they could help.
Fabrice