welcome to Apocalypse Audio, your haven for DIY guitar effects in the end times. so, start prayin to the fuzz gods, savin up those parts, and remember, when the big one goes off- keep your transistors shielded from those pesky electromagnetic pulses!



my buddy, martin from soulsonicfx, recently posted his layout for the totally awesome fourbanger.  check it out.  it's awesome.



a better treble bleed(bright cap) circuit?

on the guitarnuts forum, someone recently posted a new way to implement a treble bleed circuit using a cap, a resistor, and a dual potentiometer. the idea is, to properly emulate the frequency boost you get from the inductance of the coil in the pickup, even when your volume is rolled back. you can find the schematic, complete with frequency plots for a number of different treble bleed circuits HERE. now, how to incorporate it into a stompbox gain control...

adding a logo to your Eagle files

HERE is an excellent tutorial on Tasif Khan's page that shows you how to import your own logo for use in eagle. this is a great way to get past the limited amount of fonts that eagle has to offer. although, I have to admit, I do have a small spot in my heart for the vector font. it's just so damn old school!

capacitor switching techniques

cap switching is a great way to get more sounds out of your circuits. positioning switches at coupling caps(input or output), bypass caps, bright caps on gain controls, or tone controls can unleash options in circuits that you didn't know you had. here is a great article on Rick Viola's site where he goes in-depth into ways of cap switching that you might not have thought about yet.


pot codes

the legendary Joe Gagan found this info on a vintage radio site. I thought it was definitely worth reposting. thanks, Joe!

found this info at an old radio parts site.
this info may apply to pots made between 1930s through 60s, possibly into 70s and 80s. use the following at your own risk:

       Z = audio taper
       S = linear taper
       V = c bias taper (right hand taper)
       T = ant. & c bias taper
       U = left hand ant. & c bias taper
       W = left hand taper
       L = left hand taper
       N = left hand taper (screen grid, regen, phono pickup)
       Y = audio shunt & AVC when taper desired

       Tapers: Z = Audio Taper, S = Linear Taper


       IRC POTS: I have some "B" elements (like "Q")
       than can be used in custom pots - inquire
       They can also be used to make gang controls
       but I have no time or knowledge to make any
       complicated controls

       IRC TAPERS:
       13 = audio
       11 = linear
       14 = reverse taper
       17 = special or tone audio
       18 = special or tone audio
       19 = special or tone audio

       Most of the IRC pots with taps are for
       use in volume and tone audio circuits

       Example: Q13-137 is a audio taper pot
       Example: Q11-137 is a linear taper pot.


       Allen Bradley (Ohmite) tapers:
       U = linear
       J = taper (such as audio)
       A = unknown taper


       CENTRALAB / CRL tapers:
       6 = audio taper
       1 = linear
       2 = right hand taper
       3 = taper both ends
       4 = short taper, left end
       C1 = linear taper
       C2 = audio taper
       C3 = reverse audio taper
       C4 = audio taper - modified log 20% center,left hand
       C5 = reverse audio - modified log 20% center, right hand
       C6 = semi linear taper modified log 40%, volume, ant. shunt, c bias
       C7 = semi linear taper
       C11 to C17 = volume with tone comp.

       #1 = audio taper
       #2 = logrithmic right hand taper
       #3 = left/right taper (ant., Shunt & Bias Circuits)
       #4 = linear taper



alright, as promised, here is my latest fuzz. I described what I was shooting for a bit in THIS post. basically, I want to simplify my dirt setup, getting rid of the need for a boost, and I wanted it to be extremely versatile, with the simplest amount of controls.
now, the style of music I've been playing lately is influenced by sixties style blues punk a la gories, sonics, oblivions, them, dirtbombs, blue cheer, black keys, etc., so I really wanted to pedal to be able to do a nice, low fi-ish, but very musical, overdrive- similar to a blown up tweed, as well as a high gain sixties style fuzz for the single string square wave kind of sound. most sixties fuzzes really do not have enough sustain, and the ones that do, lack that phased out fuzzrite kind of thing that is so cool about sixties fuzz. so, since we are talkin simple here, I want to get all of that from the volume knob- none of that double stomp switch shit.
what design cleans up the best, and has that crazy impedance thing that actually brightens up when you roll back your volume knob? you guessed it, the venerable fuzz face, perfect for the first stage. many folks will bemoan the FF's input impedance, saying it ain't proper and all, but remember- this is all about simplicity. I don't need it to "play nice" with other pedals before it. it's gonna be first in the chain, and there it will stay. the clean up quality just simply outweighs any negatives that might come up.
so we have the base fuzz face design, but hey, that's kinda boring right? and it won't do the zip gun fuzz that we want with the volume dimed. enter transistor number 3. your basic inverting amplifier, but with a catch. after it is a good amount of negative feedback connected to the output of the FF stage, set up kind of like a fuzzrite with the gain almost all the way up. this gives it that bit of out of phase edge, as well as taming the gain and noise a bit, with the 4n7 cap reducing some highs.
after the fuzz face/rite action is the tone control. I wanted something that was going to be very versatile, just in case someone else isn't into the same exact sounds as me, or if it gets tried out with bass or whatever else might come up. the tc is similar to a muff style control, but the high pass cap is switchable into three ranges. the stock .001 cap gives you a very scooped sound that can do extremely bright, or rolled back gets into doom territory. adding in the 3n3 cap is usually where I keep it. you get a great upper mid crunch, that sounds great with the volume rolled back(think lofi tweed explosion), or does a nice cutting fuzz turned up. with the final option, the .01 cap in parallel with the stock 1n, on one side the heavy lows get filtered out. this gives you a nice full range sound without the mud. great for folks that want to use this as an overdrive. on the other side of the pot, all the highs get rolled off, leaving the low end intact- perfect for a fat bass sound.
you have probably noticed that this circuit uses PNP Ge transistors, so I threw a max1044 voltage converter on the power rail, so guys can use regular center positive DC jacks. all transistors are low leakage 2n1307 Ge's, with around 100-120Hfe. the pcb is not verified yet, although it is fully checked in Eagle. I will be building one up shortly for the other guitarist from the Dead Feathers. I think it'll be perfect for him.
so, there ya have it- the Naga Fuzz. i was going to call it the Nagasaki, but glorifying all that carnage made me feel kinda creepy. so now it's named after the freaky reptoid alien dudes from ancient Indian histo... I mean mythology;). look em up, some wild shit. I hope some of you guys at least take the time to throw it on the breadboard, I'm pretty happy with it. i'll try and get a YouTube video up soon.

first mod! adjust R14 for more/less separation between the two filters in the tone stack i.e. more/less low/high end roll off at the extremes. for bass, try omitting it all together. my prototype has a 100K pot here. perhaps I'll ad a trimmer in a later revision.
gah! I just noticed the power filtering caps along the bottom of the board are just barely uneven. I'm going to have to fix that, or it's going to bug me forever!