Questions tagged [guitar-pedal]

Electronics circuits design for guitar pedals

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Why are there resistors after the potentiometers in a passive audio matrix mixer?

I'm going to build a passive matrix mixer using the information on this site and this schematic: This is the first time I have built any circuits, so I've been doing some research trying to work out ...
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1 vote
1 answer
53 views

Instrument level to line level and mixing

I would like to convert an instrument level (guitar) to a line level in order to feed the isd1820 sampler chip. What are my option in order of doing so? In addition - I would like to mix the four ...
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1 vote
1 answer
68 views

Electric guitar output not working

So I (foolishly) decided to try and build an effects pedal of sorts for an electric guitar. I'm running it through an Arduino, and the signal is received by the Arduino just fine, although I had to ...
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1 vote
2 answers
87 views

Guitar distortion pedal gain

I am working on a custom distortion pedal. Here is the circuit: As we can see, we have the following flow: Input buffer -> gain stage with hard clipping -> buffer -> tone control using ...
2 votes
2 answers
80 views

Common-collector gain for guitar pedal

I am currently working on a distortion pedal. I have just made the initial input buffer to prevent loading the source signal. It is simply an NPN transistor in an emitter follower (common collector) ...
0 votes
1 answer
88 views

Changing out a capacitor with a different tolerance

I am trying to replace a capacitor in an already existing circuit. The original capacitor was 473k 100V capacitor, so it had a ±5 tolerance, but I am only able to find 473k 100V capacitors that have a ...
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4 answers
111 views

Op-amp boost pedal tonal noise

I am working on a boost pedal, but I can't seem to find the cause of a humming noise in the circuit. I tried bigger caps for C5 and C6, but it didn't solve the issue. For power I use an 18V model ...
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2 votes
2 answers
77 views

E-Guitar / Bass amplifier Effects-Loop: Is there a standard for voltage levels & impedances? [duplicate]

Musical instrument amplifiers often have an "FX-loop" with a pair of jacks which can be used to interrupt the default connection between preamp & power amp, to put the preamplified ...
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0 answers
133 views

Buffered audio splitter too hot for volume chip

I'm building MIDI controlled effects pedal that autofades the blend amount of a send-return effect loop. Still pretty much a noob on the analog side, so bear with me. Firstly I need to split the ...
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3 answers
67 views

Distortion pedal volume and tone control messing up circuit

I have built a distortion pedal with 3 variable controls: gain, tone and volume. R8 is my gain control (it will be a potentiometer with 50k to 500k resistance.) R5 is the tone control, (low pass ...
1 vote
1 answer
153 views

Distortion Pedal Design

I am building a guitar pedal and came across a reference design here: https://www.wamplerpedals.com/blog/uncategorized/2020/05/how-to-design-a-basic-overdrive-pedal-circuit/ I'm not sure why the ...
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1 answer
123 views

How to enrich harmonics in audio?

I'm designing a guitar pedal to boost harmonics in the signal here: Falstad Link I'm wondering if there are ways to boost harmonics that don't clip the signal, as well as any adjustments I should make ...
1 vote
0 answers
138 views

Use TRS jack as Mono + 5V power input

I'm trying to change this guitar wireless transmitter so that the audio input jack also becomes a charging/power source. The charger will be a separate box with "stereo" input socket. ...
1 vote
1 answer
133 views

What's going on in these op amp feedback paths?

Here is the schematic to my new Behringer UM300 guitar distortion pedal. Most of the circuitry is pretty straightforward (a lot for the $22 I paid!) but can someone explain what the emitter follower ...
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5 votes
3 answers
1k views

Overdrive guitar pedal sounds better without a clipping diode

I built a guitar pedal which looks like this (the schematic is a clone of a Tube Screamer) and I have a question regarding something unusual I discovered. There are two diodes, D1 and D2, which ...
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3 answers
252 views

Behavior of a common emitter BJT with diode from collector to base

This is the schematic for a popular fuzz pedal. I'm struggling to comprehend the mechanism. For the DC signal V1, the forward drop of the diode VF and VBE are both overcome, but when the positive part ...
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0 answers
107 views

I'm tryin' to build my own fuzz but when I plug it in my amp it just makes too much noise

If you need the schematic, just tell me and I'll draw it for you as soon as I'm home again. Anyway, it consists of 3 transistor stages with the first one having the boost control by regulating emitter ...
2 votes
2 answers
473 views

Pedal circuit not working on 9 V battery or 9 V AC adapter

I built a simple NPN fuzz pedal (negative ground) and soldered it up on some perf board. It works just as expected using my power supply but when hooking up to a 9 V battery or a 9 V DC adapter the ...
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16 votes
3 answers
4k views

Why NPN and PNP in parallel in this distortion pedal circuit?

I've come across a guitar pedal circuit called a "Tube Sound Overdrive". The schematic is shown below. It looks like a typical common emitter transistor circuit with an adjustable bias (RV1),...
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-1 votes
3 answers
166 views

Analog Delay Guitar Pedal?

I just finished designing an analog 10-band EQ guitar pedal, and it works really well in simulation. I'll be breadboarding it shortly but another idea popped into my head and I can't stop thinking ...
8 votes
2 answers
915 views

Please help me debug my circuit

I am trying to build a guitar pedal but am unfortunately failing. I have about a high school physics understanding of electronic circuits, but the readings I am getting seem impossible to me. I might ...
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0 votes
1 answer
421 views

What is a proper circuit for a variable low pass filter that can be controlled with a potentiometer?

I have some 100k digipots (MCP41100) and I want to make a lowpass filter controlled with an ATmega328P. I want a variable cutoff between 20 Hz - 20 kHz with unity gain. 1st order is enough, but it can ...
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1 vote
1 answer
330 views

Absolute value single supply op amp circuit on TL072 or MC4558

I would like to obtain an absolute value of input signal with TL072 or MC4558 op amps (or other amp) with single supply. When I connect the circuit upper one follows the signal and adds noise and ...
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0 votes
1 answer
71 views

What makes two power supplies equivalent? [duplicate]

Let's say I want to power a Digitech Obscura altered delay pedal. The recommended power supply is a PS0913DC-01. Now let's say it is impossible to get this specific power supply but we do know the ...
2 votes
0 answers
411 views

Active low pass filter built around an LM386

I have some theoretical electronics knowledge from uni, but when it comes to applying it in practice, things can get a little bit complicated. I've built simple stomp box, basically a piezo transducer ...
2 votes
2 answers
402 views

Diode in feedback path of transistor (collector-base)?

This is the schematic for a fuzz circuit. Even knowing that the diode is probably what's providing the signal clipping, I still can't figure out how I'm supposed to analyze the circuit. When V(...
1 vote
1 answer
137 views

Why does this opamp have a diode on v+

I was working on a layout for a guitar effect, and noticed on the schematic that 1 opamp has a 1N4148 diode on V+. IC6 on the schematic below. Given it has an internal power supply, I'm assuming ...
2 votes
0 answers
120 views

Can arcing in IEC 60320 C13/C14 connectors damage a device?

I have a 'guitar effects power supply' built to supply 9v/12v/18v power to 🎸 guitar effects pedals. It is powered using a IEC 60320 C13/C14 power receptacle and cable. After using this device for the ...
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1 answer
170 views

Can I use a bench power supply as a substitute for a 9V DC adapter?

I want to test a guitar pedal but I don’t have a 9V adapter around - but I do have access to a DC power supply. Is it possible* to alligator clip the +ve to the power terminal and ground to the ...
1 vote
1 answer
294 views

Switched Mono jack + battery: Make circuit when plugged in

I would like to replicate the functionality inside the Ampoids guitar amp (9v battery) in which the circuit is turned on only when you plugin a male 6.3mm mono jack to it I believe that the most ...
2 votes
2 answers
385 views

Purpose of 100 ohm resistor on guitar pedal output buffer

On the schematic for an Ibanez "Tube Screamer" there is a 100 ohm resistor in series with the output emitter follower: The output impedance of this pedal is 1.2K: It looks like RB has a ...
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1 vote
1 answer
272 views

Band-pass op-amp structure with parallel diodes in feedback?

It's been a while since I've done analog circuit theory, and I'm trying to interpret the 2nd gain stage sub-circuit in this schematic for a guitar pedal: I'm not sure if I'm approaching the circuit ...
0 votes
1 answer
143 views

Loud hum emitting from output stage of Raspberry Pi guitar pedal

I've been trying to implement the electrosmash Pedal Pi project using a Raspberry Pi 4 Model B, breadboards, and parts purchased from DigiKey. For reference, here is the overall schematic of the build:...
1 vote
1 answer
143 views

DIY distortion pedal help

I'm trying to design a guitar distortion pedal, though it is not working as expected. The built circuit behaves differently than the simulated LTspice model. I currently do not have access to a scope, ...
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0 answers
115 views

Can I replace a music toy speaker with a 6.3mm jack?

This toy keytar gas an 8 ohm speaker and adjustable output volume. If I simply replaced the speaker with a 6.3mm jack to use it with guitar pedals and speakers that can handle the line level, would I ...
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0 votes
2 answers
144 views

Guitar effect dry through circuit / wet dry mix?

I'm working on a digital guitar effect pedal, but wanted to implement a "dry through" circuit so that I could mix the digitally effected/wet signal with the original unaffected/dry signal at ...
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1 vote
2 answers
229 views

I am building my own distortion pedal but every time I connect it to a 9V power source it does not seem to work?

I am trying to build my own distortion pedal. I initially built this on a breadboard and connected it to a 9V power supply and it seemed to work fine when I connected it to my electric guitar. So I ...
0 votes
3 answers
2k views

Can I use 18AWG wire instead of 22AWG when doing guitar pedal modifications?

I'm planning on doing some modifications to my Dunlop GCB95 Cry Baby wah pedal. As far as I can tell, the hookup wire in the pedal is 22AWG (it's difficult to read what's printed on the side). The ...
0 votes
1 answer
439 views

DIY guitar pedal schematics

I'm trying to build these 2 pedals: http://byocelectronics.com/lilgrayodschematic.pdf http://byocelectronics.com/lilcompschematic.pdf both circuits have these parts separated from the "main&...
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1 vote
3 answers
293 views

Need help for troubleshooting a modification to a reverb circuit on a guitar amp to an FX loop circuit

I have a Fender Frontman 25R and I would like to use the reverb send and return as an effect loop instead. I don't mind getting rid of the reverb tank of the amp. So I found the schematic of the amp ...
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0 votes
1 answer
262 views

Switching polarised capacitors in a guitar effects pedal

I'm building a basic guitar distortion pedal, the Two-Transistor Fuzztone from the book Snip, Burn, Solder, Shred. I want to add a multi-throw rotary switch to select between input capacitors, and so ...
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0 votes
1 answer
125 views

Can I use a buffer on my bias voltage net?

I'm a french stompbox / bass guitar pedal hobbyist, probably very bad at designing them. I've been thinking about bias voltage nets for some time, and how inefficient they sometimes are. I've studied ...
1 vote
1 answer
527 views

Issues with guitar effect loop switch pedal

I've developed a circuit and custom PCB for use in a guitar pedal effects chain. This takes the input signal and switches it between 3 distinct external loops, (A, B, C) such that you can arbitrarily ...
1 vote
2 answers
463 views

TL072 based circuit generates loud noise

This circuit, designed as a bass scream, keeps generating a low noise about the same loudness as the guitar signal on the output.
0 votes
0 answers
122 views

12-15V to 9V power supply required to power audio equipment

I have a 12-0-12 transformer with output after filtering 15-16V. It's for audio equipment uses. I want to power a guitar pedal with 9V. I tried L7809 but it's making a whistling noise, so I tried ...
1 vote
1 answer
545 views

Electromagnetically shield guitar pedal

I've built a few guitar pedals using op-amps, transistors, etc. (with supporting resistors & capacitors of course), and I've generally 3D printed the housing for the components for custom designs. ...
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2 answers
442 views

Feedback Loop Filters?

In the pictured schematic, is there a band pass filter in place? I’m having trouble understanding the function of R4, R6, C3 & C4. Any help or resources would be appreciated.
0 votes
1 answer
197 views

Reducing the number of expensive capacitors in an audio opamp circuit

I'm designing a guitar effect (simple booster) which uses a CD4053 cmos switch as outlined here (http://www.geofex.com/Article_Folders/cd4053/cd4053.htm) As you can see from the second diagram, RG ...
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1 vote
1 answer
541 views

Why Does the Input Voltage Drop When a Linear Regulator is Added as Load

Why does adding a linear regulator to this circuit cause the input voltage (V_c) to drop? The 9V input coming in is regulated. The voltage measured at the branch between D5 and R22 is ~8.7 V, so it ...
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5 votes
1 answer
307 views

Need help designing and implementing an op-amp based distortion circuit

I've been attempting to design a distortion pedal for use with my bass guitar and amplifier. The simulations in LTspice were promising, I moved to implement it and, in short, it did not work. Note: ...