Sparky 5 Watt Amplifier Stripboard Veroboard Layout

I thought it was about time to tackle something that's been on my todo list for a while and that is to make a follow up to the infamous Ruby amp (made by Runoffgroove.com) which is a popular circuit among the DIY community.

So I thought the best idea was to use an amplifier IC in the same family as the Ruby's amp IC which after an extensive 5 minute search on Texas Instruments website lead me to the LM384 (DATASHEET) which is a 5 watt mono audio amplifier.
it needs a minimum of 12 volts to run though I would run it at 15 volts

All the way up it goes into crazy distortion but before that it is a really nice sounding amp, you get a nice clean and then the louder it goes the more it clips - but nicely - I must do some sound clips!

it powers a 1 x 12" cab very nicely - I've not tried it with a 2 x 12" cab yet but I think it will be fine.

so I introduce to you the SPARKY Amplifier - why did I call it the "SPARKY"? fuck knows, I think it was cause I was watching that cartoon where the piano comes to life.

Yamaha NE-1 Bass Parametric EQ Preamp ( Nathan East ) Stripboard Veroboard Layout

I'm not feeling too well so I won't drone on about this + I'm going to watch Michael Mosley documentaries for a bit.
My friend has been asking me to do a layout for the Nathan East Bass Preamp since his got stolen at a gig some years ago so I finally got around to doing it - I had to reverse engineer from pictures on the internet and it has been somewhat a pain in the ass however it now works and sounds how it should.

I didn't have the required TL062 op-amp to hand so I used the TL082 (DATASHEET) in this application there will be little to no difference to the sound - the sound is altered in the components around the amplifier.

one thing I should mention is that some people mod it by changing C4 from 47p to 220p ( I think so they can use it with their guitars. Anyway - enjoy.

EDIT: I bought another one of these preamps and C4 was 100pf in that one - so it seems that they either changed it at some point or just use something other than the normal 1% tolerance capacitors you'd usually get in this type of thing 

Self Powered 9 Volt Bar LED Battery Tester LM3914 Stripboard Veroboard Layout

another cool little voltage monitor but I had some requirements - I wanted it to be self powered and have an onboard load so I could check any 9 volt battery with it.
this is for a active pickup system so the self powered part of the design wasn't hard to factor in as usable voltage is around 5 ish volts in the EMG's I have.

and Last of all I wanted to use the LM3914 (DATASHEET) cause I've got loads of them from another project I never got around to doing.

I used a 82 ohm resistor (switched in by pressing the push to make switch) this will allow you to test the battery under a normal load which will give you a better indication of the batterys chargethe 82ohm resistor draws almost 110mA

I have done a circuit like this before which was a 0 - 10v voltage monitor (HERE) but the difference between that one and this is that this one is powered by the battery you're testing and the other one though more accurate needs a second power supply.

Amplifier Speaker Load Box 16 ohm For Direct Recording

I wanted to use my Bugera 6262 cranked up a bit so I thought I need to design a quick load box so I can unplug the speakers and put the line out into my recording interface and use software based cabinets.

There isn't a layout per se but I've provided a schematic and pictures - it is a very simple design so you should be able to follow it easily enough.
you will also notice that it uses 2 100watt 33 ohm resistors in parallel which will allow you to use amps upto 100watts or in my case (130watt) an amp not turned all the way up

you need twice the power rating on the resistors as indicated on your amp - ie if your amp is 50 watts you need 100watt resistors.

9v Fast(ish) Battery Charger Stripboard Veroboard Layout

most of the chargers I own don't work fast enough - they take in the order of 14 hours so I thought "why not make one" since I have about 30 things with chargeable 9 volt batteries in them it would be nice to make a few of these. Anyway I wanted to make one that automatically cut off but it got a bit messy so I figured I would just drop the amount of current going into the battery so I could just leave it going for a few hours.

to work out charge time: hours = mAh / mA
example case: a 9v battery I have is rated at 150mAh
150 \ 50 = 3
therefore 3 hours

the LED illuminates when the battery is connected

the Transistor (BD135) needs to be heatsinked but the LM317 doesn't so if you're using a metal case you could just screw the transistor to the case and use that as the heatsink

Floating Power Supply For DVM Panel Meters Stripboard Veroboard Layout

this was another one done out of necessity really.
I needed to power a panel meter from the same supply as I was measuring.
I actually didn't have the meter to test it with however it powered a cheap Digital Multimeter which I imagine takes up more current than a panel meter.
I also tried to make it small enough to be glued onto the back of the panel meter. 

LED Crossfader Stripboard Veroboard Layout

This was a request I got via email, they wanted the LEDs to fade in and out to mimic some aircraft lights rather than just turn on and off so I came up with this little circuit. he also wanted it to run from 12 volts - so it does.
I was going to use an op-amp at first but I thought a 555 would yield a more consistent result 

Making A Current Blasting Power Supply With Old ATX Power Supplies

what is Current Blasting? I hear you ask..
Well sometimes when you have a fault with a piece of equipment it's not always easy to track down the issue - it usually comes down to a failed component that has shorted internally - a single failed component of possibly thousands so one method of tracking it down is blasting it with high current (at a low voltage)
It is quite a fun method of trouble shooting because most of the time the failed component explodes off the board, starts smoking or gets very hot.
so what's the best method of doing this? well get a high amp power supply which costs loads of money OR make one out of an old computer power supply.
You have probably seen people make power supplies out of these before for powering their projects which I don't personally think is that great of an idea because of the high current involved but you can use it for that if you wish.

The reason why these things are great for current blasting purposes is because the junked one I have (which is from a very cheap case that had a power supply on it) has a 5volt rail of 27 amps, a 12 volt rail of 13 amps and a 3.3volt rail of 25 amps. which as you can imagine is more than enough.

now for the usual "danger" crap...
I'm sure by now you're used to reading disclaimers and warnings to the point of being desensitized by it and it is easy to ignore these things.
but these things can be very dangerous so you need to take a lot of care when building/hacking these things. They have a lot of capacitors which may retain high energy even when the unit is unplugged. you NEED to make sure they are discharged before you start handling it - that goes for the filter capacitor on the IEC mains input - sometimes they don't have a bleed resistor and can discharge 240 volts (or whatever your local voltage is) into you which I can assure you bloody hurts.

2 Things you must be aware of to use these things

1. in order to switch it on you need to solder the Green wire to Ground (black wire) I suggest
doing this by means of a switch. The green wire will be labelled "PS" or "PSON" on the main PCB

2. some ATX power supplies need a minimum load to function which is around 200mA
to achieve this you must bridge the 5 volt and Ground terminal with a 22Ω resistor.

if you're interested in how this was worked out you can use ohms law
R(resistance)=V(voltage)/I(current) so you type into your Calculator
5 / .200 = 25 so you have the answer 25Ω and you round down to your nearest value which was 22Ω in my case


Anyway here are some pictures, if you have any questions don't hesitate to ask. 

Bare ATX PCB

very cheap supply I found in my shed

I found this on the net some time ago, I'm not sure who it belongs to so if it's yours let me know and I will credit you and your site

Signal Injector / Tracer Stripboard Veroboard Layout

A quick but very useful project. I "designed" (I say designed, it's just a simple astable multivibrator with a basic transistor amplifier) 10 minutes last night and built it this morning basically to help fault find because I'm sick of having to fire up the function generator/scope when I just need a quick tester.
so as usual I will share it with you people.

Maxon OD-880 Overdrive Stripboard Veroboard Layout

Another guitar overdrive (groan) but it's a good type of thing to build when you can't think of original ideas and I am abit stuck at the moment so I thought I would find a schematic of this particular Overdrive and lash up a layout, build it and then post on here for all you people.

The original unit used 3 LM741 op-amps and I was very very tempted to just use a dual and a single op-amp instead but I know people get a bit funny about using alternative IC's and stuff even though it would sound no different, however I specifically laid it out in a way that I could make a little daughter board to use a dual op-amp rather than 2 singles to get better battery life out of the thing.

If you want to experiment some choice component values to alter would be C4, R6, R7, the signal diodes (1N4148) and R9