Guitar amp  [Builds] 


Back to guitar stuff [][][]  

I've always had a guitar lying around since i was bout 13, my enthusiasm has peaked and waned many times over the years and I don't think i have ever been particularly good. But I do like dicking about with stuff, and if you play guitar there is a never ending list things to dick about with. 









mylk386 [Brushed]  


  • Named Schematic
  • Jack PCB's Why plastic (black)
  • Etching  












mylk386 [Kit Tester]  



This one is just me doing some testing for the mylk[386] kit which I hope to be able to offer quite soon. Have been searching for a while now for some boxes to package the kit components in which could also be used as the enclosure for the amp. My initial thoughts were to try and get some sturdy cardboard gift boxes but I just can't seem to get any that are rigid enough in the size I want. Anyway stumbled across these wooden jewelry boxes which might just be perfect. Have bought and experimented with quite a few wooden boxes but the problem is the walls are always too


  • control and layout options for box 


thick to put the pots, jacks, and switches through without recessing the holes. Also the quality is usually really inconsistent from box to box . The nice thing about these ones is that the front and back is a 2 or 3 mm laminate sheet while the side walls are 5mm solid wood meaning they are really nice and sturdy but the front and back face are perfect for easy drilling and mounting of the controls and sockets. The other thing I really like is after buying the initial box to have a look at I ordered 5 more and everyone was exactly the same, perfectly clean and square....nice.










mylk386 [Etched] 

First mylk[386]amp with some proper etched graphics. Finish this time is brushed aluminium rather than polished. Used a new PCB layout in this one which is much smaller than previous versions which gives me a lot more room to maneuver inside.


  • Talk about box fabricating /etching texhnique
  • Speaker hole drilling
  • Mods to control label design  


The control labels on this one are much clearer than previous attempts but still some room for improvement. This ones actually a leaving present for my friend from work. The next ones I build will be for sale 












This is a prototype for an idea I have for a version of the mylk386 amp Kit which doesn't require a separate enclosure to put it in. The PCB and components form the internal structure of the amp which is then just skinned in cardboard which could be changed for different skins.


  • Fade on/off (warm up) LED
  • LED Clippers 
  • Add Link to card[amp]page when tidied 









mylk38 [Polished] 

2nd Prototype build for my mylk[386]amp project and the first one where I have focused on the aesthetics. Still not exactly how I want the finished product to look but definitely getting there. The etching is still not as crisp and as pretty as I would like it and the speaker placement isn't how I want it (the finished ones will be totally flush) but the polished aluminium finish is nice and I love all the black detailing. 


  • 9v Battery and Saltwater Etching 
  • PC thumbscrew feet 












Modular  Big Daddy....ish [][][] 

This is a sort of modular version of the "Big daddy" amp circuit by The bottom is a 386 power amp box (which is  basically a ruby minus the input buffer). I've been using this to test different buffers and boosters  for my mylk[386]amp project. Saves having to breadboard the same power amp portion of the  circuit every time I want to test a new idea. The top box is essentially the Booster from the big daddy circuit with a rotary switch to change the value of the cap in the bias network.


This has the effect of varying not only the amount of boost but also the frequencies that are boosted. Position [1] gives you a mild boost with a bit of sparkle, Postion [2] is a medium gain treble boost and Position [3] is full fat, full on screaming metal boost.


  • Cap Values (not shown on schematic) 


The top box can be removed and used as a standalone booster in front of a proper size amplifier. Works great if you have Low wattage single channel tube amp like a Valve Jr or a Blackheart, gives you a few more tone options from your amp without having to resort to an Overdrive pedal or Distortion.














Ruby Amp Redux [][][] 


This is my 2nd build (or re build) of the Ruby Amp (below). One thing I found with the first build  was that the amp sounded better face down when using the small in built speaker. Having the speaker facing downward decreased the harsh treble and increases the bass. I tried this idea on the Noisy Cricket build and was really impressed with the results but wanted to try the same idea in a sturdier  metal enclosure. The metal box  does seem to make a real difference. The clean sound is a lot clearer and crisper and there is a lot less vibration and buzz. As it's two different circuits it's difficult to tell how much is down to the circuit and how much is down to the enclosure but i definitely prefer the sound of this one to the cricket when going through the internal speaker (see terrible demo vid here). This amp was made for my brother in law so don't have it to hand to do further testing but if i ever find time i'll knock up another one using the Cricket circuit to do some A/B testing 










Noisy Cricket mkII - Mini amp [][][] 

    This is my build of the Noisy Cricket mkII cricuit by  The Beavis Audio site is awsome, I can't recomend it highly enough for anyone interested in Guitar related electronics. The run off groove site is also excellent but you will need to have a bit of know how before tackling some of the projects on there where as the Beavis Audio site is much more begginer friendly.  I don't think i would have been able to do half the stuff on this page without the info I found on there. 

This is their variation on the ruby amp, it's pretty much the same circuit with few value changes, plus a couple of useful additions in the form of a tone control and a  boost switch. The boost switch i love, it's just a switched capacitor placed between 2 of the pins on the chip, giving a nice boost in the gain.  You can see a rubbish demo video i did here.


 For my build i added a built in downward facing speaker and also a master volume control which can be set with the trimmer pot located underneath the amp, Although I think I prefer the harder drive of the Ruby this is a really nice sounding amp which belies it's simplicity and size - Definitely worth a go if you fancy a weekend project. See the Beavis Build and instructions here 















Ruby - mini amp  [][][]  


 This is my first proper amp build It's my version of the ruby amp circuit. I decided to build it as a mini amp with a built in speaker,  but it also works really well as a proper amplifier plugged unto a full sized guitar cab. The speaker is a 60mm paper type housed in a plastic enclosure (100x75x40mm) from maplin. the circuit has a volume/drive and gain controls, i have also added the boost switch from the noisy cricket mk II circuit which is simply a switched 47nf cap between between pins 5 and 7 of the chip. this circuit drives harder than the noisy cricket which i think i prefer. it has a nice big amp distortion which sounds surprisingly good particularly with the boost engaged.











Metal case Smokey [][][] 


This one was my first go at building a working amp from scratch. It's just the basic Smokey  Style 386 chip amp circuit with an added gain control, in a painted aluminium case . This is just a continuation of  the iSmokey idea of housing a smokey amp in something a bit more rugged and travel proof only this time I built the circuit myself instead of re housing an existing one. 
















iSmokey [][][]  


This is my Smokey amp re-housed in the packaging from an iPod shuffle. An amp in acardboard cigarette packet is great gimmick but they don't travel well. When the packet got really knackered I thought I would re house it in something more rugged. The iPod shuffle packaging was perfect. Also changed the speaker to tame some of the fearsome top end. The top can be put on to further reduce volume .This has the same effect as the old trick of turning the smokey speaker face down to lower the volume and treble.