555 Keyboard is finished!!

Been working on this since last week. You can see all the technical stuff in the previous post. Here's a  picture of it in its new enclosure:

The three controls are pitch (left), filter (center), and LFO rate (right). It's an 8 key monophonic keyboard. The highest note is the one that plays. A video will be coming soon, if you like it and would want one built for you, get in touch. Email me here: dylanpalme@heofthehouse.com

555 Keyboard

I've been planning this doo-hickey for a while now, and this morning I finally started it. It's nothing too special, just an 8 note keyboard built from a bastardized optical theremin. I added 8 N.O. pushbuttons with 4.7K resistors in between. They're wired in series which makes this thing monophonic. Here's the heart of the circuit all soldered up:

I still have a little bit of work to do on this. I'm adding a vactrol and an LM324 filter. I'll upload video and photos of everything when it's all done, so stay tuned to this blog.

Update 7-9-2011:
Have yet to add the filter or vactrol, but the damn thing died on me somehow trying to cram it into the case. Updates on this may be lacking due to the fact that I might have to build the entire thing over again. Damn.

Update a few hours later:
It's alive! It's aliiive!!

Update 7-11-2011:
Still kickin'. Installed the LM324 filter, and it sounds amazing. Not what I was expecting it to sound like (different from when I prototyped it, hmmm), but I think it sounds better. Right now it's housed in a small alarm clock case, but since I need more room, I'm transferring the circuits into a sturdier (and bigger) project box.

 I still need to add the LFO/Vactrol to the circuit. I'll end up doing that mess tomorrow. After that, all I need to do is put everything in the new enclosure and presto, it'll be done. Videos and photos will be posted tomorrow I hope.  

Mint Tin Microphone

Well, kind of. I made this out of a Sucret's lozenge tin. A LM386 simple amp circuit (you can find the schematic in the datasheet here I used the "Amplifier With Gain" schematic) wired up with a speaker for the input and a 1/4" jack for the output. It makes you sound like a carnival barker.

The only modifications I made to the schematic was to use a .1uf cap instead of a .05uf, and a 100uf instead of the 250uf cap. I also bypassed the 10K pot and just have the input going straight to pin 3.

Here's some pictures of my circuit:

It's a bit cramped, but it's a small circuit for a small tin so it's okay. So the circuit doesn't short out on the metal tin, I smeared some silicon goop on the bottom on of the board.

I also used this silicon goo to hold the speaker in place.

It's not the prettiest sounding mic, but it works.

Finished Project:

A bit cramped inside.

Listen here:
Microphone by Dylan Palme

TL082 Filter

Been messing with this thing all day. It's a very simple Highpass (sounds like one to me but what do I know?) Filter built around a TL082 Dual Op-Amp IC. It doesn't sound too bad (sound sample coming soon), but there is one problem: I can only run one or two things through it. Only a crappy 555 synth and a 555 opto-theremin work with this filter (and the theremin barely works through it). I was wondering if the kind folks out there in the internet could possibly help me out and let me know what the heck I'm doing wrong.

Here's the schematic:

Gafilterfuzz

I've been messing with this guitar pedal for a long long long long time. Not because it's an insanely complex circuit, just because I've been lazy. It's really simple, and really fun. It's based off an LM324 quad op amp chip and random parts I had laying around.

Parts:
(1) LM324
(1) 100K Pot
(1) 10K Pot
(1) 4.7K Resistor


And obviously you need the standard 3PDT switch, in/out jacks, 9V battery clip/AC Jack and that kind of junk.

Schematic:

It's a little iffy. From my testing, when the battery is low, you don't get much fuzz from it. Build it, share it, have fun with it. If you have any mods, post them in the comments.

Listen to it here:
Fuzz Demo by GuyIncognito