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



So..."What the fuck is a mylk[386]amp"? I hear you ask. Well in a nutshell it is my attempt at creating a more versatile and usable version of the Ruby and Noisy Cricket LM386 chip powered guitar amp circuits (published by and 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 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 wears off.


 The first one is the lack of gain. Don't get me wrong, like bashing out Jimi Hendricks licks as much as the next man, but I also want to be able to play 'cowboys from hell' and butcher 'sweet child o' mine' occasionally. It is possible to build a version of the Ruby with a booster pre-amp (Big Daddy), rather than a buffer, 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 limiting 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... Ok, so I exaggerate slightly but the point remains. 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.  




How do I build it [][?][] 


Well that's sort of up to you, that's really the whole point of the circuit . 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 beginner DIYer 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 needs or just what you have in your parts bin.

If know what you are doing and just want the basic schematic with some suggestions regarding control choices and values, click here or on the image above for the main schematic page with build notes. If you are relatively new to DIY 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 set of named schematic variations which can be made from the base circuit board layout to give you some idea of the kind if things you can do with the circuit. 






Parts List


Here are the components you will need to build the mylk[386]amp. I have separated the parts out into the core Circuit board components and then the options for control choices. I have tried to Tune the circuit to use as many of the same component as possible so you do not have to order a bag full of obscure part  just to build the amp. 




Here is a veroboard layout for the amp designed to fit on a standard 25 x 9 hole piece of  veroboard or stripboard. This is the base circuit layout which you can then modiy to build the amp how you want it 














How does it all work ? 

The Ruby and Noisy Cricket can be separated into two distinct blocks. You have a JFet Transistor Pre-amp block and a 386 chip power amp block.



Both the Ruby and Noisy Cricket circuits use the cheap, ancient and ubiquitous 1w, JRC/LM386 Power amp chip which was first popularised for guitar use by the incredibly cool Smokey Cigarette Packet amp designed by Bruce Zinky in the 80's. Because of its low cost and excellent overdrive characteristics the 386 chip has since become a staple of Low power DIY guitar amp circuits the world over. When pushed hard, most solid state power amp chips clip like smashed glass being scraped down a gravel drive, the humble little 386 chip however clips like an absolute fucking champ which is why it is so popular.

The other thing is the very annoying "Master Volume" control which which mimics tube amp's of yore (and now) by placing the volume control in front of the power amp. Now to be fair this is an entirely conventional set up but leads to exactly te

All "Master Volume" tube amps are built this way and so are the overwhelming majority of all Solid State amplifiers, But they are built this way through necessity rather than design. As mentioned above, solid state power amps normally clip like broken glass so the conventional way to build a solid state guitar amp is to use a multi stage pre amp circuit to sculpt the tone and provide the clipping (Overdrive/Distortion) and then use the power amp to cleanly amplify the resulting signal. Tube amps use the same set up, but as we all know unlike a solid state amp the real Joy in playing through a tube amp is getting the power amp valves to overdirve and sag. The only way to do this is to crank the "Master Volume" to get the power amp overdriving





I'm not one of those people who likes making things just for the sake of it. You will never catch me building an Arduino powered LED strip or 

Other things you could try

Creative Commons License