Piggyback Pair

Germanium transistors are becoming more and more scarce and the ones that you do find aren't great options for the classic fuzz circuits. If only there was a way to use silicon transistors, both cheap and readily available, to simulate/emulate germanium transistors. Well the Piggyback method of tying two silicon transistors together does exactly that. It also allows the gain of the end transistor to be dialed in via trim pot. There are a few pedals on the market that use this method to produce their tones but it's really not that common. Try it out.

Scream & Whisper

My take on one of the most famous pedals to ever be made, the Tube Screamer. I've added some quaint modifications and value changes and added a transistor based noise reduction circuit. The actual screamer side of things is based off my personal Hudson Electronics Sidecar pedal, he threw in some odd valued and unnecessary capacitors but otherwise its a solid pedal and my favorite derivative. The noise reduction circuit is a loose interpretation of the 'one knob noise gate' project from the DIY forums. I stacked my op amps but to be honest couldn't really tell the difference, but it's got that cool factor now so....... 

Optical True Bypass

 I found this one on FuzzDogUk's website. Its a neat way to use DPDT switches for true bypass and still get the indication LED. This is totally doable via the Millennium Bypass family of circuits but I just thought this was an easy project to do. Who doesn't like options.

 

Please Leave A Message After The Fuzz

The ISD1820 Record/Playback IC has seen a resurgence in use the last few years. MidFi Electronics released his Propaganda Machine, Parasit Studios Subspace, BASTL did a project, WRAA did a project, Casper Electronics has fucked around with them, and even I myself have made a few designs with the old girl. Here is a pretty gnarly fuzz I whipped up. The tone/filter control is pretty versatile and has a wide sweep. Something different than another boring transistor fuzz. Check out my other projects using this chip the 'Flooper' and the 'Always Remember To Never Forget".

 

Overprotective Parent (I'm 18 & Moving Out)

 Exact same circuit as the original but with the added onboard charge pump. Circuit will prevent damage from over voltage and is resettable/reusable over and over again. Refer to the original for more information. 

Overprotective Parent

 This is one of the coolest circuits I've been able to wrap my head around. An overvoltage and polarity  protection circuit that wont require the any parts to be changed or re-soldered due to misuse. The only pedals I've had to fix for people were broken because their "friend" accidentally plugged in the wrong power supply and fried some internal components. This little circuit will prevent those parts from getting fried, and will also save the hassle of having to repair it. What is commonly referred to as a 'crowbar circuit', it baffles me that this isn't more commonly implemented. 

Basic Math

Circuit consists of two transistor based drone oscillators tuned to different pitches. With a little experimenting and knowhow this could easily be turned into a working keyboard/piano. I'm pretty positive that this is how a lot of transistor organs function under the hood. 

 

Answers

This is part 2 to the "Questions" circuitry. Both circuits need to be built and used in tandem in order for the desired results to be achieved. Please refer to the previously mentioned "Questions" circuit which is shown in a separate post. 

Questions

 "Questions" is part 1 of a 2 part novelty "wireless" transmitter and receiver circuit and will not function by itself, it must be paired with the "Answers" circuit (shown in separate post). I initially discovered this circuit(s) on a random diy forum, it was originally posted by a high school teacher from Australia and I'll be damned if I can remember the fellows name. All in all a good step into the world of wireless.

Radio(active) Fuzz

This is a unique and interesting fuzz circuit I found deep in the depths of the aronnelson archival website. The main IC is an AM/FM Radio chip and is used/abused to make a wide range of fuzz tones. Full blown silicon, gated velcro, 8bit, bitcrusher, and just general noise. The original designer left the project unfinished and with a few different modifications, I started with his schematic on breadboard and just experimented from there with values and a few other mods. These chips are still available on ebay and there's also several others in the same family that more than likely have an equivalent pinout. I encourage some more modifications and experimenting. 

ReValver

Have you ever been playing your favorite pedal, or any pedal for that matter, and thought to yourself "gee, this sure would sound better with tubes"? Well with the ReValver now (almost) any pedal can have a tube! I say 'almost' as I've tried all my pedals and while they all work, not all sound great. I tore apart Matsumin's ValveCaster circuit and did a little experimenting. Essentially adding a send and return into the middle of the valve circuit, injecting whatever effect into the 12au7 and adding that "warm" tube sound to say a...fuzz or a....delay.....or a flanger...etc.

Tap On Tap Off True Bypass

I started experimenting with some 9volt relays recently and this was the obvious first circuit. A means of turning on and off/bypassing effects via a momentary 'soft switch'. There's a few other methods of accomplishing the same feat though using slightly more complicated circuitry and/or parts. The 555 timer is cheap and readily available due to its vast uses. Any relay should suffice, I've tried 3 separate brands and all have function accordingly.

Ruby Amplifier

Not the greatest little practice amp but it's a cool project nonetheless. Only capable of roughly 1/2watt it's best suited for small speakers, large speakers will work too however. Low parts count and a quick build. Originally designed by RunOffGroove as an updated version of their "Little Gem" amplifier. I needed this when I was trying to design the layout for the "What Goes Up Must Come Down v1".

12 Over 2 Equals 6 Point 3

This is an almost useless circuit, at least to me anyways. I needed 6.3v for a tube project I was working on at the time and this was my way of getting there. While it does provide 6.3 volts I unfortunately failed to read the specs of the tube's heater draw and this method (LM317) ultimately doesn't give enough amperage for what I was doing. Lesson: always read the datasheet.

Ambient Light Synthesizer

Similar to how the Atari Punk Console functions but his time controlling the oscillation with an LDR and the ambient/surrounding light. The drone is constant, even in a dark setting, but the more light the LDR receives the higher the pitch of the drone becomes. Another simple, fast, and rewarding build using the 555 timer IC.

 

8 LED Random Flasher

The name says it all. Just another cool way of controlling LEDs for various projects. Someone could take this a step further and make a random sequencer. 

Always Remember To Never Forget

The ISD1820 voice recording IC has gained some popularity recently and has popped up in a few other cool projects and guitar effects. This one is pretty simple compared to those. It's a lofi sampler/looper essentially. Signal is split at the input via the 2N5457s and half of that is fed into the recording IC, while the other half remains clean(this allows your signal to be heard while in 'record mode'). There are three separate methods of playback: momentary, latching, or looping. Depending on where the sample rate is set at you get 8-20 seconds of recording time. Once a sample is recorded it's playback speed can be altered for some really cool and unique sounds. Special thanks and credit is due to BASTL and WRAA whose experiments with these voice chips is where my projects all stemmed from.

Wiggler (slow)

Same circuit as the regular "Wiggler" but with modified components/values to allow for slower speeds. Not much else to be said that hasn't already been mentioned in the original post.

Wiggler

A phase shift oscillator, courtesy of the Magnavibe. While it's not as powerful or as sophisticated as the Tremulus Lune oscillator, it's a much easier build and provides the needed controls to drive a lot of LDR circuits. "Depth" controls the brightness of the LED, whilst "Speed" controls the rate between fading on and off. I've also made another version of this circuit that allows for much slower speeds and will post it separately. At one point I made a "compact" layout of this circuit but it wasn't that much smaller and looked a little untidy, but if space is a concern you could shave off a couple rows and columns if you wanted.

Wiggle Wobble

Out of all the subminiature tube projects this one takes the cake. It's a tube powered vibrato, and it's lush as fuck! In the notes it says that by omitting one of the trace cuts you can get more of a tremolo effect, in retrospect I think this would be better implemented via a switch to connect/disconnect the trace cut therefore giving two effects in one. This circuit is a two part build and will not operate without a secondary 'LED' circuit to drive the LDRs. You can use any LED circuit you'd like however I found that a smoother fluctuation(fade) as opposed to choppy(blink) is more desirable in the actual behavior of the LED(s). Rick Holt who originally designed the circuit used a transistor based LFO, in my personal build I used the phase shift oscillator found in the Magnavibe pedal. I'll post a few layouts for the phase shift oscillator(PSU) that I used in another post.