simplest LFO synth for beginner

jamiewoody · January 28, 2010, 05:36:20 PM

the beginner would be me.

could someone please point me in the right direction for a very entry level 556 timer based lfo synth?

i have a couple of 556 timers, i have .01, .1, 10, 4.7 uf caps, misc resistors and pots.

basically, i want to do the one with the fewest connections possible, and then, once it is working, get creative and start adding more pots, etc.

i am looking for something diy or illustrated. i am not up to speed with schematics as of yet.

can anyone link me? thanks.

Gordonjcp · January 29, 2010, 02:18:11 AM

Look up the datasheets for 555 timers. They have a whole range of example circuits. Build one audio oscillator and get it working - using the example circuit in the datasheet - then build a low frequency oscillator that you can modulate your audio oscillator with.

Congratulations, you've just invented your very own dub siren.

Circuitbenders · January 28, 2010, 07:27:45 PM

Quote from: Gordonjcp on January 29, 2010, 02:18:11 AM
Congratulations, you've just invented your very own dub siren.

all the cool crowd are doing it

jamiewoody · January 28, 2010, 09:25:42 PM

i'll try that. i'm dying to build something from scratch! then when it is working, bend what i built, and create my own monster! ;-)

i am okay with bending, i have now bent 4 keyboards, and a couple of other things. i want to start making things from components now.

jamiewoody · January 29, 2010, 09:13:17 AM

i did it!!!!

i made an lfo based on the atari punk console. i poked around and found some other controls as well. SICK distortion and squelch tones! glitch heaven!

i am praying i can find a switch to go between the negative on the battery terminal to switch it off. i can short circuit it with the pot to turn it off, but i want to have an led indicator and schtuffs!

Timodon · January 30, 2010, 12:17:14 AM

Don't forget Pics/ audio video when you finish it Jamie... APC is going to be my next project when I finish on the MT twins...

Circuitbenders · January 30, 2010, 02:29:19 AM

i'm a bit confused here. When you say LFO do you mean VCO?

A synth entirely based on LFO's wouldn't make any sound as the oscialltions would be too Low Frequency.

jamiewoody · January 30, 2010, 12:08:35 AM

it is very possible i could be confusing my terminology. i'll look up "vco".

one problem with my atari punk console (based on the drawing by andrew carrel, with a few bends here and there). is that it seems to be sucking batteries fast. i am not sure if it has to do with the quality of the dollar tree 9 v's i'm using, or what. i think my next step will be to try it out with a wall wart and see what happens. any ideas?

the components:

r1: 4k7 (which was confusing, was this a 47k resistor or a 4.7k? there were other designs i saw with 4.7k resistors, so i am assuming this would be it.).
r2:1k
r3:10k
556 dual timer
ca: .01uf
c2: 1uf
c3: 10uf

there is no diode in this design. maybe i need to add one in series with the potentiometers as mentioned before?

another thing i am running in to is the fact that i need to buy stripped pc boards. i got some of the radio shack boards that have copper dots around the holes, but no stripes.

oh well. when i pay my $200 electric bill (OUCH!) maybe i will make another order to bg micro and get a bunch of stuff i need.

jamiewoody · February 02, 2010, 11:41:11 PM

i started to lay another one of these out. i did a lot cleaner soldering job, almost immaculate! i at least got all of the components in place and soldered on the board. at that point, electricity to my house died, as there was a snow storm.

talk about timing! i was on a roll!

Remork · February 05, 2010, 10:35:49 PM

4k7 = 4.7k
just as, say, 1M2 would equal 1.2M
or, with capacitors, 2u2 would equal 2.2uF.

so that's a correct assumption allright

jamiewoody · February 06, 2010, 12:33:29 AM

thanks. a hack like me made a safe assumption, who'da thunk it! ;-)

i plan to build about 5 more atari punk consoles as soon as i can order some more components, and sell them on feebay.

jamiewoody · February 18, 2010, 12:54:47 AM

i have been trying to wrap my mind around the condept of the atari punk console. not how they are made, as i have made one.

but, as i understand, the basic circuit was not even called APC, nor was it ever a commercial product. it seems more like it might have been an educational product. comments? beuller? beauller? lol!

i have noticed, most of the 556 timer synths i have been digging around for, voice of saturn, etc seem to be based on this basic design.