bdnotch Bridged Differentiator R/C notch. Alternative to the Twin-T notch filter. Easier to tweak and use in my opinion. Date: 01/20/2008 Bridged Differentiator R/C notch. Alternative to the Twin-T notch filter. Easier to tweak and use in my opinion.
bdbandpass Bridged Differentiator filter (alternative to the Twin-T), in feedback loop of an active component. Produces a frequency-sweepable bandpass/wah filter. Date: 01/20/2008 Bridged Differentiator filter (alternative to the Twin-T), in feedback loop of an active component. Produces a frequency-sweepable bandpass/wah filter.
wtd Date: 01/22/2008
CMOSwah Date: 01/26/2008
CMOSwah2 Date: 01/26/2008
diodes Date: 03/04/2008
measure_tape Date: 03/15/2008
IMG_0815 Date: 03/15/2008
proto_supply Schem for my pedal prototyping rig's power section. Haven't worked the bugs out yet... Date: 04/06/2008 Schem for my pedal prototyping rig's power section. Haven't worked the bugs out yet...
IMG_0846 Date: 04/09/2008
clip2 Date: 04/27/2008
clip2 Date: 04/27/2008
Fun with CMOS Date: 05/04/2008
Fun with CMOS 1 Date: 05/07/2008
untitled Date: 05/09/2008
IMG_0820 Date: 04/01/2008
ncw Date: 05/20/2008
ncw1 Date: 05/23/2008
Buffy49 Date: 05/30/2008
Theremin Light Project name: New Project
Credits: Project credits...

Group Name Value Part # Quantity

Capacitors 10n 1
Capacitors C1 33p 1
Capaci Date: 06/10/2008 Project name: New Project
Credits: Project credits...

Group Name Value Part # Quantity

Capacitors 10n 1
Capacitors C1 33p 1
Capacitors C3, C4 100p 2
Capacitors C5, C6 10u 2
Diodes D1, D2 1n4148 2
Diodes D3 Bright White 1
Integrated circuits IC1a 4049B 1
Integrated circuits IC1b 1
Integrated circuits IC1c 1
Integrated circuits IC1d 1
Integrated circuits IC1e 1
Resistors R1 1M 1
Resistors R11, R2 470 2
Resistors R3, R5, R10 100k 3
Resistors R4 100 1
Resistors R6 33k 1
Resistors R7 10k 1
Resistors R8 20k 1
Resistors R9 47k 1
Transistors Q1 1

Created with freeware DIY Layout Creator
Earth and Space Interface Lights up the LED when you get closer to the antenna. What what! Date: 06/24/2008 Lights up the LED when you get closer to the antenna. What what!
Earth and Space Wah Inductorless Wah for guitar or bass plus distortion... or not. Date: 06/25/2008 Inductorless Wah for guitar or bass plus distortion... or not.
Proximity Wah Prototype Date: 06/27/2008
Proximity Wah Prototype2 Date: 06/27/2008
Proximity Wah Prototype3 Date: 06/27/2008
Earth and Space Wah 2 Submission for FX-X July 2008 (no externally adjustable pots) Date: 06/29/2008 Submission for FX-X July 2008 (no externally adjustable pots)
dpdt Switching options for "multiple presets" Date: 08/26/2008 Switching options for "multiple presets"
asymmetry switch Shunts one of the clipping LEDs with a Shottky diode. Date: 09/02/2008 Shunts one of the clipping LEDs with a Shottky diode.
fab echo with time knob and expression input Fab echo with adjustable delay time and modded for infinite repeats. The delay time resistor has an LDR/LED in parallel, with a 1/8" jack to control the LED. Date: 09/02/2008 Fab echo with adjustable delay time and modded for infinite repeats. The delay time resistor has an LDR/LED in parallel, with a 1/8" jack to control the LED.
room for battery Another view of the asymmetry switch Date: 09/02/2008 Another view of the asymmetry switch
sleeper ts7 Looks stock... but it's not. Date: 09/02/2008 Looks stock... but it's not.
tone gain Adjustable gain for the tone stage, allows for big treble boost when the tone pot is up full. Date: 09/02/2008 Adjustable gain for the tone stage, allows for big treble boost when the tone pot is up full.
Modded Steby Fuzz Layout Date: 09/12/2008
4049prox Date: 09/12/2008
funkyDOA Discrete Op-Amp Date: 10/04/2008 Discrete Op-Amp
UberBooster Discrete Op-Amp set up as a booster/overdrive. Date: 10/04/2008 Discrete Op-Amp set up as a booster/overdrive.
pair not a Darlington Date: 10/16/2008 not a Darlington
pair Date: 10/17/2008
Bootstrap Fuzz/distortion uses bootstrap technique. Bootstrapping allows use of a wide range of hFE with surprisingly little variation in tone. I tested different transistors with hFE from 90 to 500 and the sound changed very little. Subtle, but not as much as y Date: 11/02/2008 Fuzz/distortion uses bootstrap technique. Bootstrapping allows use of a wide range of hFE with surprisingly little variation in tone. I tested different transistors with hFE from 90 to 500 and the sound changed very little. Subtle, but not as much as you'd expect. Everything has an effect on the sound, but the only parts that are critical are the resistors on the emitter and collector of the PNP. Don't make the emitter one too small or the collector one too big or it sounds like poo.
untitled Idea for simple, optical compressor/expander Date: 11/06/2008 Idea for simple, optical compressor/expander
untitled Idea for simple optical compressor/expander Date: 11/06/2008 Idea for simple optical compressor/expander
Bootstrap_layout Layout for "...but first walk a mile in someone else's bootstrap"
UNTESTED as of 11/8/08 Date: 11/08/2008 Layout for "...but first walk a mile in someone else's bootstrap"
UNTESTED as of 11/8/08
Bootstrap_layout Layout for BFWAMISEB (...but first walk a mile in someone else's bootstrap). October 2008 FX-X entry.
UNVERIFIED as of 11/8/2008 Date: 11/08/2008 Layout for BFWAMISEB (...but first walk a mile in someone else's bootstrap). October 2008 FX-X entry.
UNVERIFIED as of 11/8/2008
ramp Ramp-and-hold control voltage circuit Date: 11/19/2008 Ramp-and-hold control voltage circuit
Unistage Screamer Single stage non-inverting diode feedback clippers Date: 12/04/2008 Unistage Screamer
Single transistor voltage gain stage with diode clippers in the negative feedback loop and minimal parts.
Cap from base to ground keeps input impedance relatively high (100k).

Not verified, but I think it would work. :)
pwmed Concept for simple but powerful class D amplifier using self-oscillating PWM input stage.
Op-amp is LM386 power amp. Date: 12/05/2008 Concept for simple but powerful class D amplifier using self-oscillating PWM input stage.
Op-amp is LM386 power amp.
pwmed Slight revision, fixed the part where the audio signal screws with the high voltage supply... oops. Date: 12/06/2008 Slight revision, fixed the part where the audio signal screws with the high voltage supply... oops.
unistage1-1 Unistage Screamer with mods suggested by DougH. Corrected as of 12/10/2008. Date: 12/10/2008 Unistage Screamer with mods suggested by DougH. Corrected as of 12/10/2008.
tempo UNVERIFIED!!! Date: 12/12/2008 UNVERIFIED!!!

Update (3/19/09): Verified!!!
PT2399 Tap Tempo Refined the basic idea for PT2399 tap-tempo. Not verified. Still not entirely sure about some of the connections, but it's getting there. Date: 12/13/2008 Refined the basic idea for PT2399 tap-tempo. Not verified. Still not entirely sure about some of the connections, but it's getting there.

Update (3/19/09): Breadboarded and tested, works exactly as predicted. Haven't hooked up a PT2399 yet, but the output voltage does exactly what it should. Press button, output of amp B immediately goes high for a very short instant then falls linearly for as long as the button stays pressed. Let go of the button and it holds that voltage. :)

For more "normal" operation, the delay output or pin 6 should be muted while the ramp voltage is changing, or build as-is for wacky pitch bends during the tap interval.
scoop_freak Date: 12/21/2008
peak_freak TS-style gain stage with resonant, sweepable mid boost... CONCEPT, not tested yet. Date: 12/24/2008 TS-style gain stage with resonant, sweepable mid boost... CONCEPT, not tested yet.
Earth and Space Interface2 Date: 01/10/2009
pwr Power filtering and polarity protection Date: 01/19/2009 Power filtering and polarity protection
sync Screamer-based amplifier snippet using synchronous rectifier MOSFETs for gain control.
***UNVERIFIED*** Date: 01/20/2009 Screamer-based amplifier snippet using synchronous rectifier MOSFETs for gain control.
***UNVERIFIED***
sync Version 2. Date: 01/21/2009 Version 2. Works at extremes of pot rotation, but in between is very hard to control.
phase Phase splitter/pan Date: 01/28/2009 Phase splitter/pan
stoob Date: 01/31/2009
1bitFlanger Rough outline for a 1-bit flanger/time delay idea. Date: 02/08/2009 Rough outline for a 1-bit flanger/time delay idea.
bufferer LM386 "buffer" Date: 02/11/2009 LM386 "buffer"
DiffOctFuzz ***UNVERIFIED*** concept for diode-less, discrete transistor-less octave up fuzz circuit. Date: 02/26/2009 ***UNVERIFIED*** concept for diode-less, discrete transistor-less octave up fuzz circuit.

Update (3/19/09): Verified, does not work as intended. Some octave up effects were barely noticeable at some settings, but overall the effect is more of a clean boost/square wave blend.
tempotocurrent Interfaces Molten Voltage's MV-52 tap tempo IC with Princeton Technology's PT2399 delay IC. Tap tempo for delay time. (Unverified 4/15/2009) Date: 04/15/2009 Interfaces Molten Voltage's MV-52 tap tempo IC with Princeton Technology's PT2399 delay IC. Tap tempo for delay time. (Unverified 4/15/2009)
buster Simple op-amp boost with easy buffered bypass. High Zin, low Zout, full frequency response. Date: 04/19/2009 Simple op-amp boost with easy buffered bypass. High Zin, low Zout, full frequency response.
Simple PWM Amplifier Simple PWM amplifier Date: 04/20/2009 Simple PWM amplifier using 386 audio power amp IC. Input buffer should be added for best performance.
dutyrateosc High-frequency, squarewave oscillator with rate and duty cycle controls. 50:1 rate(with 15V supply) and 0-100% duty cycle. Additional switch and capacitor give LFO range. Date: 04/23/2009 High-frequency, squarewave oscillator with rate and duty cycle controls. 50:1 rate(with 15V supply) and 0-100% duty cycle. Additional switch and capacitor give LFO range.
remote Idea for remote guitar volume knob (for buffers before fuzz) Date: 04/28/2009 Idea for remote guitar volume knob (for buffers before fuzz)
Untitled Boutique Date: 05/19/2009 Boutique
autojosc Possible oscillator for "auto-Juggler" concept. Date: 05/21/2009 Possible oscillator for "auto-Juggler" concept.
ota Date: 06/17/2009
slackplus Date: 06/21/2009
ducker Suggested mods to SeanK's "Ducker" Date: 06/23/2009 Suggested mods to SeanK's "Ducker"
Continuous Polarity Gain continuously variable from -1 to zero to +1. Date: 06/29/2009 Gain continuously variable from -1 to zero to +1.
Continuous Polarity Date: 07/10/2009
mfscre Date: 07/31/2009
pwmenv IDEA (unverified) for detecting signal envelope after crude pulse-width modulation. Date: 08/14/2009 IDEA (unverified) for detecting signal envelope after crude pulse-width modulation.
comp Switched-capacitor compressor... or at least that's what it's supposed to be. Date: 08/31/2009 Switched-capacitor compressor... or at least that's what it's supposed to be.
led Date: 10/09/2009
squareshape Simple square wave shaper (passive) Date: 11/13/2009 Simple square wave shaper (passive)
zxr ZXB minus the inductor, slightly improved biasing. Date: 12/10/2009 ZXB minus the inductor, slightly improved biasing.
IMG_4111 Holiday Date: 12/20/2009 Holiday
xmasnoise Date: 12/27/2009
pipecleaner Date: 01/16/2010
2to3switching Date: 01/17/2010
pipecleaner1 Revision 1 Date: 01/17/2010 Revision 1
High-pass-switching Date: 03/10/2010
tonefreakfuzz original design fuzz/distortion Date: 03/15/2010 original design fuzz/distortion
IMG_4297 Date: 03/03/2010
IMG_4303 Date: 03/15/2010
cablestretcher Date: 04/09/2010
cablestretcher cable stretcher, rev. 1 Date: 04/11/2010 cable stretcher, rev. 1
100r Date: 04/15/2010
IMG_4571 Date: 04/19/2010
IMG_4577 Date: 04/19/2010
Untitled Bronx Cheer with op-amp, optional gyrator for FX-X May 2010 Date: 05/21/2010 Bronx Cheer with op-amp, optional gyrator for FX-X May 2010
zng May 2010 FX-X entry 2: "Zinger" Date: 05/26/2010 May 2010 FX-X entry 2: "Zinger"
zng May 2010 FX-X entry 2: "Zinger" Date: 05/26/2010 May 2010 FX-X entry 2: "Zinger"
pwr Date: 06/10/2010
crossingover EarthTonesAudio - "Crossing Over" distortion device Date: 06/13/2010 EarthTonesAudio - "Crossing Over" distortion device
IMG_5082 optical epoxy knob Date: 06/25/2010 optical epoxy knob
IMG_5083 Date: 06/25/2010
htri Date: 08/20/2010
mudoubler Where's the beef, ...I mean capacitor? Date: 10/16/2010 Where's the beef, ...I mean capacitor?
less_noisy_ensemble Anchovie's "Noise Ensemble" modified for less noise (less distortion) Date: 10/25/2010 Anchovie's "Noise Ensemble" modified for less noise (less distortion)
less_noisy_ensemble Anchovie's Noise Ensemble modified... again. This time with more gain and some regen. Date: 10/27/2010 Anchovie's Noise Ensemble modified... again. This time with more gain and some regen.
recessed_knob Date: 12/08/2010
sdcomp 1-bit sigma delta based compressor, low parts count. Clock circuitry not shown. !!!UNVERIFIED!!! Date: 12/21/2010 1-bit sigma delta based compressor, low parts count. Clock circuitry not shown. !!!UNVERIFIED!!!
sdcompR1 Revised Sigma-Delta Compressor. Still UNVERIFIED Date: 12/22/2010 Revised Sigma-Delta Compressor. Still UNVERIFIED
ptlfo Triangle wave LFO made using PT2399 and CMOS 555. Date: 01/21/2011 Triangle wave LFO made using PT2399 and CMOS 555.
uncanny valley modified suggested mods to Taylor's Uncanny Valley Date: 01/21/2011 suggested mods to Taylor's Uncanny Valley
UncannyValleyMod Not-working mod to Taylor's "Uncanny Valley Bit Manglor" Date: 01/27/2011 Not-working mod to Taylor's "Uncanny Valley Bit Manglor"
supply Date: 02/01/2011
UncannyValleyRemix "Remix" of Taylor's Uncanny Valley circuit. Uses CD4051 and 6 pots (not shown) for 6 discrete output levels per full-scale analog input voltage. Adjustable input Z and hysteresis on one control. Date: 02/10/2011 "Remix" of Taylor's Uncanny Valley circuit. Uses CD4051 and 6 pots (not shown) for 6 discrete output levels per full-scale analog input voltage. Adjustable input Z and hysteresis on one control.
avtr avatar Date: 02/10/2011 avatar
3bits Date: 02/13/2011
3bitAGC 3-bit folding ADC used in feedback loop of automatic gain control circuit Date: 02/16/2011 3-bit folding ADC used in feedback loop of automatic gain control circuit
waveio What the ADC/AGC can do Date: 02/16/2011 What the ADC/AGC can do
3bitmangler 3-bit ADC controlling attenuation of audio signal Date: 02/16/2011 3-bit ADC controlling attenuation of audio signal
4bits Theoretical/unverified 4-bit folding ADC Date: 02/17/2011 Theoretical/unverified 4-bit folding ADC
nbitADC 5-bit folding ADC. Drawn this way it is easier to see expansion to n-bits. Date: 02/24/2011 5-bit folding ADC. Drawn this way it is easier to see expansion to n-bits.
pwmlfo PWM controller for CMOS switch, manual or LFO variable Date: 02/25/2011 PWM controller for CMOS switch, manual or LFO variable
pwmlfo pwmlfo with audio-controlled gate. Date: 03/02/2011 pwmlfo with audio-controlled gate.
jfetbias 3 ways of using an opamp after a JFET gain stage Date: 03/09/2011 3 ways of using an opamp after a JFET gain stage
PWMultiFX Aliaser/Tremolo thing Date: 03/11/2011 Aliaser/Tremolo thing
AmpElevenSettings Date: 03/17/2011
ADCvoltage Date: 04/01/2011
OPOC_eta_mods Date: 04/05/2011
tim_my Date: 04/08/2011
3BFF Date: 06/24/2011
3BFFbrd Unverified as of (24 June 2011)
Mostly I wanted some practice doing a PCB layout in Eagle. :) Date: 06/24/2011 Unverified as of (24 June 2011)
Mostly I wanted some practice doing a PCB layout in Eagle. :)
silver_freeze_revA UNVERIFIED as of 6/25/11 Date: 06/25/2011 UNVERIFIED as of 6/25/11
OctaveDown my idea for a simple implementation of the "other" clean octave down method. Unverified. Date: 06/28/2011 my idea for a simple implementation of the "other" clean octave down method. Unverified.
Untitled fuzz, play-nice-with-others! Date: 09/07/2011 fuzz, play-nice-with-others!
Untitled Date: 09/21/2011
PTselfTapping Date: 09/28/2011
3sc_HB Date: 10/03/2011
Multiplex Idea suggestion for frequencycentral's mini-vocoder idea Date: 10/05/2011 suggestion for frequencycentral's mini-vocoder idea
engine Date: 10/10/2011
Screen shot 2011-10-11 at 12.35.36 PM Date: 10/11/2011
Screen shot 2011-10-11 at 12.36.16 PM Date: 10/11/2011
tickticktick Date: 10/19/2011
zotl Date: 10/24/2011
DSC00101 1590A! Date: 11/02/2011 1590A!
Screen shot 2011-11-21 at 10.02.07 PM Date: 11/21/2011
sumdiffswitch Summing Switch Hitter Date: 12/07/2011 Summing Switch Hitter
paralooperSCH modified paralooper Date: 12/09/2011 modified paralooper
IMG_8053 Date: 12/09/2011
Return to Sender buffered splitter mixer with phasing and feedback controls Date: 12/12/2011
up Date: 01/17/2012
futurecomp Near-future "desktop" computer Date: 04/10/2012 Near-future "desktop" computer
PTdata Date: 05/21/2012
photo Date: 06/11/2012
simpleVU Date: 07/02/2012
airgap Date: 09/19/2012
airgap2 Date: 09/19/2012
airgap3 Date: 09/19/2012
image Date: 12/27/2012
image Date: 12/27/2012
image Date: 12/27/2012
image Date: 01/10/2013
therm_mod Date: 02/15/2013
optical_bias Date: 03/03/2013
photovoltaic_jfet_bias Date: 03/04/2013
photovoltaic_jfet_bias Date: 03/04/2013
pullhere Date: 04/29/2013
ckt Date: 05/10/2013
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