4093 Quad Oscillator Kit
The GetLoFi Quad Oscillator Kit is based on the 4093 Logic IC configured to create four independent oscillators controlled by knobs. The resulting sound can vary from rhythmic beeping to polyphonic drones.
Price: $35
Please order the Quad Oscillator Kit from the www.getlofi.com/shop
Instructions: howto.pdf
Demo:
From the GetLoFi.com/shop you can also purchase an acrylic panel that is laser cut and fits perfectly inside of a Radio Shack Medium box enclosure.
If you have a some sheet metal or an Hammond type enclosure then you should be able to use this Drill template to make all of the potentiometer controls line up. Note that this design includes a hole for the Tone knob and DC jacks, which are not part of this kit, but can be added separately.
Vinyl cutouts are a great way to decorate and identify your device. Be gentle with sliding the knobs to the potentiometers, its possible to press them too close to the case and loose some of the smooth rotation action. Do not force or glue these knobs down.
User Builds:
Any hints on how you wired the tone control or how you built one at all?
The tone control is very simple and much like a Tone control on the guitar. Simply wire to the output a 1K linear potentiometer connected to a 10uF capacitor going to Ground. This will create a Low pass filter.
What would be the best pots to use for volume control?
Also, if i wanted to have two 4093 quad oscillators in one enclosure and have them wired up to the same power supply, what kind of power supply would i need to use to have them both operate at “normal” behavior (as in, if they both had their own 9v power supply)? Um . . . 18v?
Thanks for your help.
You could probably use a 1K potentiometer for volume control. Simply replace the 100ohm resistor included in the kit, which mounts on the output jack with a 1K potentiometer. This will attenuate the signal by “mixing” in more of the Ground.
Well if you are using a DC power supply, then I’m guessing both will work fine wires to the same jack. Ideally you would have a voltage regulator on each unit. This will assure clean and interference free power supply. Otherwise you can just wire up the kits as is and use two 9 volt batteries one for each. Just mount it all in the same box, there will be zero cross talk that way.
I just finished with the build and housing of this
And was wondering if it’s possible to connect it to the sequencer kit
Thanx
It is possible. The sequencer simply outputs a 9 volt trigger which can be used to power the entire Quad oscillator circuit or if divided by a potentiometer can be used to chance the voltage on the oscillator pots. There by chancing the pitch.
I was looking into purchasing one of your kits but i was wondering, Is it possible to put a 1/4″ insert so i can send signal in and get an output response with different frequencies? I know its kinda out there but i just wanted to know if it was possible! thanx!
You can’t just wire up a 1/4 jack into the circuit and have it follow your guitar lets say. Extra circuit is required. You could use the Envelop Kit to connect to the Quad oscillator. This will give you a Gated response from the Oscillator. To control the pitch of the oscillator you would need some sort of a Frequency to Voltage converter. It is possible, but will require some work.
Same general idea, yes.
o ok but could i do it without the envelope kit? like is there a place on the main board to put an insert?
No you can not add an Input without another external circuit.
just another dumb question lol, does this kit come with 5 knobs and the silver level like pictured in your videos and finished kits your selling?
Hey Garret, actually that is a great question.
The extra 5th Knob is the Tone stack, it cuts out the High Frequency much like a Guitar tone control. This is an optional addition, I will publish a diagram for adding that eventually.
Basically its a 1K Potentiometer from the Tip pin of the output jack connected to a 10uF capacitor running to the Ground. All those parts can be purchased from the GetLoFi shop separately.
so this kit does not come with the tone stack
No it does not. Its an extra feature that I’ve been adding to my Quad Oscillator pedals.
ok cool what is the name of the tone knob at ur store?
Just finished building mine today. Too bad, extremely low output signal, with a MS-2R hooked up i have to max Volume and Overdrive only to get a very quiet sound. Tone control does nothing except lowering the volume. On the other hand the oscillators work as expected, clear and stable… Now i’m a bit lost, because it’s the first project ever to fail for me and i can’t find any wrong connections… and I built lots of pedal FX over the years, last project was a Nebulophone several weeks ago for example and it worked at first try, not a single error.
OK, I guess it’s got to do with the f…. universal diodes I had to use (could not get the required 1N5230 in Germany). I bridged them with several salvaged diodes I had laying around and the signal increased a little bit. The 1N5817 sounded best but i only have three of them left, bad luck
Seems like I’ve got to poke around a little more 
DCP, so you did not get the Kit? or just the PCB?
Yes the correct diodes are very important.
I ordered 2 PCBs and then I found out i couldn’t get the right diodes but in the meantime i found some in the salvaged parts box that work quite well. I just had to swap the 100 Ohm resistor between signal and ground for a 100K one. That adjusted the output to an acceptable level. And the tone control just acts like a volume control not changing the tone at all. Let’s see what stupid mistake I made connecting it this time
Try looking at this image some more, the Tone is wired up in there. Use a 1K potentiometer and a 10uF capacitor.
http://www.getlofi.com/wp-content/uploads/2011/04/DSC06788.jpg
Yes, that’s how I connected it. From tip to the pot, from there to the + side of the cap and the – side of the cap to ground. Never mind, i will find out what’s going on sooner or later, the most important thing is that i got the volume to an acceptable level
Strange, the tone works really well for me. Are you using an Audio curve 1K potentiometer instead of Linear? Perhaps its those diodes messing it up too.
Must be the diodes… I changed the cap to 100nF and it works as tone control now.
Attention people, to make things clear, what I`m writing here is only valid for the parts I had to use for the circuit, if you got a kit from GetLofi you should of course use the provided parts! My problems with the circuit are homemade and can be avoided if you have the right parts at hand
There’s just one more thing I discovered while poking around in the circuit: I put a 1kOhm pot between the battery + and the circuit board +. The lower I turn the pot the more funny digital noise I get out of the circuit. Voltage drain galore. Haven’t checked it with a wall wart power supply yet.
Thanks for that disclaimer dcp
Nice work on the starve feature! Also if you hook up the Envelope kit to the Quad oscillator it does something similar, more glitchy sounds.
I would be very interested in seeing a picture of your build.
dumb question. where can i get a 9v dc input. the place i get my bits through don’t have them, and you don’t have them listed either.
Hey KoG,
I just added the DC power jacks to the GetLoFi.com shop in the parts section. Thanks for a great suggestion.
[...] new 4093 Quad Oscillator Kit is now available in limited quantities from the GetLoFi.com/Shop. Please also note that many [...]
Hi
here’s a quick demo of my modified 4093 kit
I hope you enjoy it.
Enrico
http://youtu.be/hNktUCFkYzM
this is an amplifier or tone control?sorry im just a begginer..tnx
Hey CM, quick question
If you were to connect a CV input, what pins would you attach the tip and sleeve wires to the 1/8th inch input? I’m guessing there is 4 possible configurations…
Any help would be great! Thanks
the pcb in the “how to” pdf looks a bit different.
erm…when will these return to stock?
many thanks…
Hey MCP,
I will restock this week. Sorry for the delay.
Did I miss the restock? Been unplugged for a few weeks. when can we expect more?
Hey Justin, hopefully in a week or so.
hi-will it be possible to add photocells for each one of the oscillators?
and can you purchase here?
hanks
Matt
Sure, I have photocells in the shop.
hi, sorry for the dumb question, but what are the photocells for? and can i use it as a guitar pedal, with a blend knob? sorry for asking this, but my knowledge is completely restricted to soldering.. i dont get much about eletronics. thanks