mylk[386]amp 

"A low watt DIY guitar amp you can actually use"

 

 

So..."WTF is a mylk[386]amp"? I hear you say. Well I'm glad you asked. In a nutshell it is my attempt at creating a more versatile and usable version of the Ruby and Noisy Cricket LM386 powered guitar amp circuits (published by Runoffgroove.com and BeavisAudio.com respectively) to use in my Travel guitar and Mini amp designs.

 

The Ruby and Noisy Cricket circuits both sound fantastic and are great fun to build thanks the LM386 chip, low part count and all the free info available online. They do however have a couple of major drawbacks I wanted to tackle which I think limits their usefulness long term and results in most of them ending up on a shelf to gather dust once the novelty of having built your own amp wears off.

The first one is the lack of gain. Don't get me wrong, like bashing out Jimi Hendrix licks as much as the next man, but I also want to be able to play 'cowboys from hell' and butcher the 'sweet child o' mine' solo occasionally. It is possible to build a version of the Ruby with a booster pre-amp (which sounds awesome) rather than a buffer, called The Big Daddy, but then you lose all the cleaner tones ... and I want both God damn it!

The second is the annoying "Master Volume" which places the only volume control before the power amp which works fine in a normal setup because power amp chips usually clip like smashed glass being scraped down a gravel drive when overdriven... The 386 chip however clips like an absolute fucking champ (soft clipping like a tube power amp) so all the "master volume" does is limit your tonal choices to whisper quiet 'Stairway to Heaven' or 'Back in Black' at a volume that is likely to leave you with permanent tinnitus ... because you can't increase the gain to any reasonable degree without also increasing the volume (and 1 watt running at full chat through a 10 or 12" guitar speaker is a fuck of a lot louder than you think it is).


 

mylk[386]schematic

"A complicated schematic you can actually read" 


 

 What I have tried to do with the mylk[386]amp is to take all the things I love about the Ruby and Noisy Cricket circuits such as their simplicity, circuit board size and big amp sound, and create something that has lot more range and flexibility while still remaining simple enough for your average DIY er to tackle. The amp can be wired up a number of different ways from the base schematic allowing you to tailor the amp to suit your tonal needs or just what you have in your parts bin. So weather you want a high gain death metal machine that makes pinch harmonics squeal of the fretboard , or a vintage sounding crunch amp with a mild boost for solos, you can build it from the same schematic and layout just by changing the control configuration and values. 

If you know what you are doing and just want the basic schematic with some suggestions regarding control choices and values, click on the image above for the main schematic page with build notes. If you are relatively new to electronics or would just prefer to avoid "the tyranny of choice" ruining what would otherwise be a fun weekend of building something cool ... below is a stripboard layout and a set of named schematic variations to give you some idea of the kind of things you can do with the circuit.  

      

 

 

 

 

 


If you are thinking ... "Well that all sounds fucking awesome Jody, but I can barely read a smokey Schematic, let alone build one. How am I meant to tackle this fucker and not end up with a battery powered paperweight that just squeals at me like a stuck I pig every time I so much as look at it funny".  Well the good news is you don't need to be able to read a schematic to build the amp. As long as you can handle a soldering iron and can follow some stupid, brightly coloured crayon drawings ...you should be ok (and you might even learn how to read the schematic along the way). Click on the image below for the parts list or the  image above for the step by step  version of the stripboard layout.

 

The layout is designed to fit on a standard 25 x 9 hole piece of veroboard or stripboard (which is tiny and should fit in just about any enclosure you want to put it in). The strip board layout and parts list are for the base circuit board. On top of that you will need to select how you want to wire up the controls from the 3 options below.

 

 

Use any single op-amp chip with 741 pin outs ... TL071, TL061, etc

 


 

 

 

 

FULL FAT - This one is for all the Tweakers, Modders and obsessive compulsives out there. This uses all the the controls available and provides the most rang of tones. Use this one if you are building yourself a full size head or combo amp, or for building a test rig to experiment with the circuit. Using this set up you can also easily add in extras such as a FX loop and/or Tone Control. This set up is essentially a simplified tube screamer (Drive and Level) mated to a LM386 power amp (Gain and Volume).  

 

 

 

 

 

LOW FATThis one is the one I recommend most people build and how I generally build the circuit. Unless you are obsessed with experimenting with sounds you really wont miss the Level (master volume) control and this build of the amp provides the most plug in and play satisfaction. Every setting sounds good and the Gain switch (rather than pot) gives you 3 distinct and useful power amp settings to flavour the overdrive. If you are building a little practice/jam amp or mini head ... Definitely build this, it will provide all the tone options you could need without the unnecessary fat.  

  

 

 

 

 

  

FAT FREE - This one is for the micro builders out there. If you want to build yourself a teeny tiny amp that that will fit in a Fag packet, this build of the amp provides you with just the essentials. The missing Gain switch can be replaced with a resistor  ditch the bright switch as well if you are really trying to save space or switch the Br

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LINKS

http://www.runoffgroove.com/ruby.html

https://www.electrosmash.com/lm386-analysis


Creative Commons License