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.

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...

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...

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.

This is a commonly used and very simple circuit for a passive tone control as used in the Big Muff Pi guitar pedal.  I’ve tested it with a 10k logarithmic potentiometer and it would definitely work more effectively with the 100k linear potentiometer as indicated.

Here is a portion of the low power LM386 based guitar amp I am prototyping.  This is an audio buffer used for the input stage of the amplifier. Most people would use a simpler circuit built around a FET however I did not have any FET transistors within immediate reach so I did a whole bunch of fiddling around on my breadboard trying various other components I did have. This is what I found worked with the NPN audio transistors I was able...