Brian May Deacy Amplifier Stripboard Veroboard Layout

Although I am mostly into 90's SkatePunk I am a massive fan of Queen and Brian May, when I was young I obsessed over having the guitar, the homemade deacy amp and the rangemaster - I have the guitar and the rangemaster however until now I didn't have the amp.
So for this weeks project I have laid out the Greg Fryer designed version of the Deacy amplifier.

I got the 2 transformers from eBay - apparently people get "better" sounds from hammond transformers and you are of course free to try what you want but for mine I used the LT44 and the LT700.
according to various sources the speaker used is a 6" one with 4 Ohms impedance. the impedance is pretty critical to the sound of it, I didn't think it would be so vastly off but when I plugged it into an arbitrary 16 ohm speaker I thought it wasn't working correctly however I decided to change the speaker anyway and it sounds like it should.

it's also worth mentioning that this is a rare occasion where I laid out the stripboard and I made no mistakes, usually what I do is lay out a board then check a day later - usually find a few errors, then check another day later and so far this method has seen me with 100% success rate with stripboards

anyway the circuit is a pretty simple push pull amplifier that was used a lot in little radios during the 60's onwards  in fact it is very similar to a mullard 1 watt amplifier from that era.

Brian May says in various articles that he used a wah pedal to shape the sound along with his treble booster and microphone positions and if you move this thing in different directions you can hear how he got some of the sounds.
anyway on to the layout.

it's also worth mentioning about the whole positive ground thing, back in the olden days they used to have positive grounding rather than the more normal (now) negative ground. it's okay though even though it says -9v on the stripboard all you have to do is connect the negative to the -9v and the positive to the ground and it will work - this amplifier was originally battery powered so using pedals wasn't an issue however should you wish to use a power supply then you need to use a separate one to any pedals you have plugged into it or it won't work

inside the cabinet

Constant Current Led Tester Stripboard Veroboard Layout

Not really much to say about this thing really except that when it is powered at it's optimum voltage (12v) it tests LEDs at about at a current you set with the 100k pot.
I made this because I have tons of LEDs in a component bin and not only did I not know if they worked but using this I can match them for brightness because I'm sick of projects looking half arsed with different brightness LEDs

The other LED based use is that when you buy lots of LEDs from a one-hung-low chinese source on eBay there can be the odd batch of crap ones and it's best to find out before you spend 4 hours troubleshooting a project only to find it was the LED that was bad.

Boss FA-1 Stripboard Veroboard Layout

the fabled FET guitar preamp, something I bought before it got all famous. it is a good device but they can't be made anymore because the monolithic preamp ICs inside it were discontinued however I have cloned my FA-1 replacing the preamp ICs with 741 ICs and honestly, it sounds exactly the same and you get the same voltages at important test points within the 5% tolerance range set by Boss on their original service manual schematic. and this is because the sound isn't in the IC it's in the circuit! the filter stages and so on. obviously different ICs have different gains and bandwidths but in the case of a guitar effect unless the IC has a significant gain difference you won't hear a difference. which is why I get so annoyed with people who say they have "modified" a guitar effect by changing an op-amp or when they describe a certain op-amp as being "warmer" anyway I won't go into all that crap.

here is the layout and my schematic for the Boss FA-1 - I included my schematic because even though you can readily find the original, it leaves out important information like op-amp inputs, I had to figure out whether connections went to inverting or non-inverting inputs for example.
someone else worked the circuit out using a dual op-amp however he was reluctant to share the schematic for people (there were comments asking but he never posted it and you just have to think - what a dick)

The FET - in both my schematic and layout I used the MPF102 however using this particular FET will add a lot more clipping and if you wish to have a cleaner sound go for the original 2SK246 - however I warn you it has a different PINOUT so you may have to do some leg bending.

VOLUME POT - you need to use a LOG pot not a Linear one

spot the difference

someone on twitter asked me how to add a switching jack so I drew this - I thought I may aswell add it here

555 Astable Timer Circuit Fragment Stripboard Veroboard Layout

I thought I would lash up a quick Astable 555 timer layout because this is one circuit that gets used a hell of alot - I certainly do. I included a little bit of math on the schematic but that's purely for the sake of it, normally I would just use a trimpot or something unless space is at a premium however even then it's not that important because you can use a trimpot/resistor substitution box to find the value required rather than doing boring mathematics.
it's always best to just try things until they work the way you need it to work otherwise you get bogged down with boring numbers.

I was also going to include the "one shot" version of the circuit because it's pretty useful when you need to convert something like a tact button press to a specific timed pulse so you don't get ghost switching but in the end I didn't, I'll save that till next time I can't think of something to do

EDIT: I just realized I made a little error on the "boring math shit" I meant to write for "t1" (R1+R2)xC1= 1.5mS
it doesn't really matter regarding the stripboard - that's fine, I just wanted to correct the little Math I do

Candle Flicker Stripboard Veroboard Layout

My candle flicker effect

I shall try and give a little explaination of this circuit as it is one that is pretty useful as a Random Number Generator.
what is happening is that there are 2 square wave oscillators giving outputs at different rates to each other
so when both inputs of the NAND gate "accidentally" hit a logic high the output is low this in turn goes into a further NAND gate configured as a inverter ie when both the inputs are a logic low the output is a logic high.
the CD4093 is a pretty useful IC - in this one circuit we have the CD4093 configured as 2 oscillators, a NAND gate and an Inverter.
the Inverter output is then connected to a PNP transistor which switches on the LED when the logic output is low on the inverter.
using a PNP in this manner is how I included an indicator LED on my Atomic Frequency Standard as it outputs a Logic low when it locks in.
so anyway the CD4093 NAND Gate basically boils down to the following statement:

Output of a NAND Gate = 1, if any of the inputs = 0
                                           0, if all of the inputs = 1

so anyway, boring crap aside - this little project emulates the flicker of a candle, it works best in the dark of course. As you will notice there is a second LED output, this is basically just a dimly lit LED I added to because a real candle doesn't turn on and off when it flickers, so if you hot glue them together then you get a more realistic flicker.

Article on "the next decade" from 1975, from the magazine Practical Electronics

I found some old electronics magazines in my Great Uncles loft after he died which I kept, whilst reading through them I came across this fantastic article about the next decades advance in electronics written by readers so I just had to scan it - open in new tab/window to view it properly

LM3914 Voltage Monitor Stripboard Veroboard Layout

This is pretty much a datasheet circuit that I put onto stripboard
it has a monitor LED that turns off when it drops below 8 volts however by changing the placement of the resistor you can make the LED go out at any voltage for example if moved the resistor leg from pin 12 on the IC to pin 14 on the IC the LED would turn off when it drops below 5volts

A Word On My Schematics and a 10 Hour Timer

Some of you older people (my age and older) may notice that some of my schematics resemble that of the old Forest Mimms schematics IE, drawn on graph paper. This, of course is on purpose.

When I was growing up I would often spend a lot of time in the electronics shop Tandy (Radio Shack in the US), it had actually gotten to the point where the shop assistants knew me (I was about 7) and would even look after me while my mam went shopping. The electronics educational books they had were all the forest mimms ones so they'd let me sit in the corner reading them so I have a lot of fond memories attached to the Forest Mimms books which is why as an alternative to drawing my circuits out in EAGLE (which I have with some of them) I would pay homage to Forest Mimms and use his method of hand drawing schematics on graph paper. not only that but it really is a great way of drawing schematics. using a CAD program is all well and good but it takes longer and you end up with computer blindness if you do lots at once.

The one little bit I've added to make it my own and because when reading schematics I hate having to look them up, is adding little pinout drawings of any discretes and/or ICs used

Anyway back in school I designed this little circuit after my dad moaned at me for being on the phone to my girlfriend of the time for too long. there's no veroboard layout because I did this with wire wrap - in fact it was just not practical to use stripboard for this circuit because it would have ended up being hundreds of jumpers.

Remote Control (IR) Tester Stripboard Veroboard Layout

this was a real quick design which consisted of basically powering a IR Sensor that I removed from an old DVD player - sending the output to a PNP transistor. initially just to make a LED light up but then I thought making a sound would be better so you could just point and click so I'm sure just by looking at the diagram you can work out what's going on.

but a "flowchart" of the circuit is
the sensor senses and outputs through a transistor base
the activated base allows the emitter to pass current to the collector
this powers the LED and 555 timer circuit which is just configured as a basic astable multivibrator

it kind of sounds a bit like a quiet pneumatic drill - this sound is the 555 timer being activated by the remote controls data transfer which is in packets (packet data) - I said the word packet 3 times and now it sounds weird in my head.

anyway if your remote is working you'll hear this sound, if it is not working and you have changed the remote controls batteries, the remote is broken. besides the obvious problems that can effect a remote control like murky battery contacts, moisture (it's better off not knowing what and why that moisture is there), dust and so on then a common issue is that the transmitter LED has failed which is easy enough to replace.

Decision Maker With Slow Down Veroboard Stripboard

I've wanted to make one of these for a while, I am terrible at making decisions - if someone asks me anything where I need to make a decision I freeze up so over the years I've made various yes/no machines but they were never quite right because they didn't slow down, they just stopped. 

This is quite a simple little circuit, so simple I don't know why people haven't done it before - sure there are heads or tails type decision makers out there but they light up and stop when you release the switch where as this one slows down to a stop which feels more random than the other method.

the main difference between this circuit and the usual heads and tails circuit (which I got from my 130 in one electronics project lab) is that this one charges the 22u capacitor which discharges through Q1 basically lowering the voltage to the 555 oscillator, as the voltage lowers - the oscillation gets slower and as it depletes it stops on red or green - or whichever colours you choose

when you turn it on for the first time you'll notice that one of the lights are lit - this is normal.
the explanation for this is that the CD4013 is a dual integrated flip flop circuit so it's always in one state or the other - it usually starts up in the same state every time.
when you press the push to make switch both LEDs will light up, maybe with a little flicker and once you depress the switch they will start to slow down till they make their choice.

operating voltage is between about 6 - 9 volts any lower it will tend to favor one state over the other.

C5 - in the schematic, this was left out of the stripboard because it's not really needed so don't worry about this. I thought there might be an issue with DC hum but there wasn't

TRANSISTORs - Although I stated BC549s in the stripboard, you can use most general purpose transistors like 2N3904s for example.

my rather unimpressive boxed up version

Nintendetar Add-On Oscillator Veroboard Stripboard

one of the first things I made in order to sell was the Nintendetar guitar effect, this basically reshapes an input signal as PWM - it has proven reasonably successful though not successful enough to sell out of them!
anyway I have always been meaning to design a little add-on for it to make it more animated and finally I have done. Rather than redo the whole board and annoy everyone who bought the original I thought I would make a little stripboard add on daughter board so anyone that already has one can just add the board to their existing nintendetar effect.Here is a little song I did with the nintendetar to just show what it was good for Nintendetar Full song

the tricky part was getting rid of oscillator "ticks" which I managed with the aid of my resistor sub box (build one!) and getting the right rate range which turns out to be best between 0.3Hz and 4Hz ish - this particular oscillator is a Triangle one however you can also get some cool effects inputting different signals - a fast 10 - 20Hz squarewave for example give you a good stutter type effect

Op-amp +/- Power From Single Supply Fragment Stripboard Veroboard

a simple little circuit that will help anyone really new to electronics. you'll see a lot of circuits that have ICs that require a split power source IE +5 volts and -5 volts, there are quite a few ways of achieving this, ranging from the full on voltage regulator method (so you have a LM317 and a LM337 with a center tap transformer) to charge pumps or you can use a voltage divider or in the case I have laid out, a voltage divider with a unity gain buffer to give you a virtual ground. basically the circuit splits the input voltage in 2 and makes a center reference point between the 2 voltages - that's the really stupid way of explaining it anyway.

for the sake of better performance (especially for you audioweirdos) I have included capacitors on the input however usually I wouldn't bother including them because I put filter caps on the main power supply but I put them on the layout for the sake of completeness.

it maybe worth noting that if you saw my headphone amplifier circuit earlier on, I used a different type of voltage divider, quite similar to this without the op-amp buffer but instead of giving me dual voltage supply, that one gives me a Vref of half the Vin.

anyway here is the circuit

LED Display UP Counter Stripboard Veroboard (CD4026)

I wanted a counter that would basically count from a input signal, such as a reed relay to count the turns when winding a transformer or inductor for example. so I came up with this. I limited it to 3 digits (so it counts up to 999) because I only had veroboard big enough for that many but technically I don't think there is a limit to how many you can cascade because the CD4026 basically counts to 9 and sends out a clock signal on ten to the CLK in on the next chip

quite a simple circuit in theory but a pain in the arse with the jumpers and stuff, in order to try and save space I made jumper rails  with little wire hooks which I've drawn on a little post-it note to try to show you what I mean, though I do tend to put the jumper a lot closer to the board than the diagram shows of course!

while building this up, I came across the issue where if I touched it, it would start counting up rapidally - this was because my body was acting as an antenna for 60Hz mains hum which can be an issue sometimes so I added a little R C bit to stop this and this also served to make it reliable when using a push-to-make switch to count on it.

if you want the exact LED displays I used it was this one LED DISPLAY but any common cathode display will do as long as the pinout is the same (shown below