The saga continues – this version of the circuit is one I am quite proud of. There is no dirt or distortion options in this design, I was going for as loud and clean as I could drive the LM386N amplifier while getting a nice rich sound. Schematic Power & Input Pretty self explanatory. The power can be a standard 9V battery or it can be a switching jack for AC adapter 9-12V. The power switch is not shown, but it’s...
Read MoreMiniature Guitar Amplifier – Two Channel Improved
Based on last night’s previous ramblings regarding implementing dual channel settings with a bit more control over how it all works together, I started looking at how other amplifiers accomplish this feat. Looking at some existing solid-state amplifiers, the above diagram seems to represent a simplified version outline of how this might be achieved. I found some op amps in a piece of old audio equipment which I will be using...
Read MoreMiniature Guitar Amplifier – Reverberation (Feature Creep)
While looking over the corpse of an old Archer Surround Sound Amplifier that is being stripped for parts I came across an interesting component – an MN3008 chip. The data sheet describes it as a “2048-stage low noise BBD” – this is an audio delay chip which was probably used as part of the “synthesized stereo” effect on the amplifier.
I wonder if it could be turned into an on-board reverb effect, or perhaps into a DIY guitar pedal. Definitely worth looking into.
There are some mystery ICs that I have not been able to find data sheets for thus far, I am hoping that they are op-amp chips which would come in very handy for my guitar amplifier circuit.
Read MoreMiniature Guitar Amplifier – Dual Channels and Effects Looping (Feature Creep)
While researching and coming up with ideas to make a simple battery powered miniature guitar amplifier sometimes fanciness and elegance creeps into the conceptual stage. Here I will be rambling on about a few ideas and theories with which to complicate and elaborate on what is at its core, a very simple and effective design. The amplifier I’ve built so far is very similar to The Noisy Cricket and is based off of the general theory...
Read MoreMiniature Amplifier – Putting It All Together
Based on my previous posts of some simpler amplifier components, here is a block diagram of the amplifier: The input buffer I used is an NPN transistor circuit I cooked up from various ideas online. Common wisdom is to use a FET however I did not have one available, but I did have a handful of C945 transistors scavenged from an old tape deck. I then used the circuit for passive tone as used in Big Muff guitar fuzz pedals. I have...
Read MoreMiniature Guitar Amplifier – Amplifier Core
This is essentially a Ruby type LM386 based amplifier. Very basic and simple, but quite powerful. This is the standard Ruby circuit, although I believe my prototype version is a little different.
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