Audio Function Generator Stripboard Veroboard Layout

there isn't really much to say about this circuit as it is mostly a 8038 based function generator with a few bits added on such as a DC-DC convertor for the bi-polar power supply and a range/shape selector switches etc.
the ICL8038 is rated to range from 0.0001Hz to over 300KHz however the sine on the one I built up stops becoming useful at about 300KHz and it starts at about 10Hz however this maybe because I exclusively use parts from broken stuff - the IC was harvested from a PEAVEY classic chorus amplifier that died years ago, The pots came from an old mixing desk and so on so you may get closer to the rated range however 10Hz to 300KHz is fine for most if not all Audio applications.

I should also mention the LT1054 DC-DC converter, I got this as a free sample from Linear Technology and I used this over the more common MAX1044/7660 ICs because I need 12+/- volts and the 1044 has a maximum rating of 10 volts.

Notes:
The ICL8038 does get quite hot
Make sure the capacitors are all rated at 35volts or above

Linear - Log etc. Potentiometer Conversion

sometimes it's not always possible to get the response you want from an existing potentiometer and sometimes like me, you don't want to have to keep buying loads of different types of potentiometer
or you're just too lazy to reach upto the draw with the log pots in and the linear ones are nearer, whatever the reason you can alter the response curve using the following schematics - I didn't bother doing a stripboard layout for these because it's pretty much 1 or 2 resistors - I tend to use resistors the same value or higher than the pot value however you can bias the curve response to one side or the other using lower values that the pot.

anyway experiment until it does the right thing, that's the best way

White Noise Generator Stripboard Veroboard Layout

This is a very basic circuit which consists of 2 parts
1st is the noise generator which is the first transistor with no collector connection
2nd is the bit which may look more familiar which is an AC common-emitter amplifier and this is just to bring the noise upto a usable level - I have taken a scope screenshot of what the noise looks like however it is an audible sound which is pretty useful for testing guitar fx or filters and other such things.

if you wish to learn more about the common-emitter amplifier the best source for information is "The Art Of Electronics" book - on page 77 almost the exact same amplifier circuit appears with explanation 

you can of course experiment with different types of transistor in the noise section - i'm not sure how available the BC108s are now, I just happened to have a load of old ones, I hit it with a hammer to get a bit more noise out of it.

the best voltage I've found to use this at is 18volts however it does make noise at 9volts upwards

LED Ring Oscillator Stripboard Veroboard Layout

This was kind of a rush thing I did today because I have a few projects awaiting various IC's which I can't publish yet but I haven't posted anything this week so I thought I would lash up a LED Ring Oscillator - I'm sure you've seen these things on the net in various guises, mine has increasing value resistors which basically makes the oscillator more predictable in the way it rotates and which LED starts first which was quite important for this as it's going to be part of a LED/LDR circuit

you'll notice that the schematic I've done isn't in my usual notebook format but instead I used a program from the CD off the front of a magazine called circuit wizard - it's okay for testing little circuits like this so I thought I would just upload the schematic I drew in that

anyway as usual the stripboard has been built up and it works - the rate is voltage controlled so the less voltage you feed into it the slowed the LEDs will light up - my favorite voltage is about 3.3v which is cool for uController projects that already have that voltage available - I've tested mine upto 16 volts but I couldn't go any further due to the capacitors I was using.

 

Electronic Symbols

I've been quite unwell so I have been unable to face firing up the soldering iron, I've just been lying in bed feeling sorry for myself - I do have a few layouts but they aren't verified yet so I won't post them yet. however I did sit in bed drawing out some of electronic symbols I use the most (and by extension everyone else should too!) so I will share the scan here - hopefully people will find it useful.

Sound Fuckulator Stripboard Veroboard Layout

first of all I have to apologize for the lack of schematic (unless of course one has appeared) I designed this on a stripboard layout (in DIY stripboard editor) so in order to get a schematic I will have to reverse engineer it
to be honest I didn't think it would do anything but it does, it makes my guitar sound nasty and horrible which is perfect for doing little weird bits in songs - it uses the LM567 ( NE567 or whatever ) which is a tone decoder IC which I happened to have some of lying about - well in my IC draws.

so here it is

Door Bell Beeper StripBoard Veroboard Layout

Another circuit born from necessity, the story goes like this, the door bell I have is a wireless thing that needs it's battery changing every 2 minutes - it constantly draws 600uA in standby and jumps up to 80mA when the bell is pressed and then there is the transmitter which I haven't bothered measuring.
so because during this week the batteries went flat I missed the post twice, I assumed that the first time it was just because I was playing music too loud and didn't hear the bell but the second day this was not the case so I figured time to make my own with the following specs - less standby power use and loud as fuck.

anyway what happens in the circuit is that pressing the switch discharges the capacitor into the IC which allows it to carry on beeping untill the capacitor drops below a certain voltage I won't go into detail about the fucntionality of a Logic NAND gate because there is a brilliant site that covers it in a simple manner HERE

however I have taken a screen capture of my scope to show you the voltage waveform as it discharges into the circuit. you'll notice at first the waveform has bumpy bits, that's the actual beeper circuit powering the speaker and as you can see the beeping lasts for about 1.5 seconds which is long enough when you hear this thing.
it draws about 150uA in standby and about 30mA when it's making a sound so it beats the stupid piece of crap I currently have.

sorry for the lack of real explanation on this circuit but I've got a bastard of a migraine 

Simple Sweep Generator Stripboard Layout

A very simple Sweep Generator - it goes through the audible (and beyond) range which is useful for Impulse Response recording and other stuff of course.
it also kind of sounds like one of those woop sirens from sci fi films

Treble Booster/Overdrive For The Deacy Stripboard / Veroboard Layout

after building my Deacy amplifier it was obviously missing a vital part - the treble booster Brian May used
however instead of just building up the rangemaster (which is a fine booster) I thought I would make my own from scratch - first of all I didn't want to go for a Germanium Transistor as is most common with these kinds of guitar process pedals because Brian actually had a treble booster based around a silicon transistor (BC182) which was what I was going to use initially but then I thought "nah - try and be at least a little bit original" so I went to my component bins and found a 2N2484 - well I found a 2S733 first but I couldn't find an online seller of them which would be pretty important for anyone else who builds this - so I built it around the 2N2484 which is readily available from places like farnell.

anyway when building this kind of thing there isn't so much leeway on how you build it, it's essentially an amplifier and a filter type of thing, the designs choices you get to make are the component values and in my case I wanted to keep the nice chime type treble boost but allow a bit more bass through
I also put in a gain pot. you may notice if you look at the schematic that there is a capacitor going to the gain pot from the output line. the reason for this is that an audio signal is AC however when you sweep a pot wiper from ground you get noise in the form of DC which presents itself as horrible low frequency crackling noise, using a capacitor between the output and the pot stops this as a capacitor decouples DC but leaves AC in tact.
the less resistance to ground there is, the less output you have however I have used a 10ohm resistor to limit the volume reduction so the pot sweeps from clean to overdriven

it sounds ace anyway