# Questions tagged [distortion]

Distortion is the alteration of the original shape (or other characteristic) of a signal representing an object, image, sound or waveform.

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### Can 3rd order intercept point be used to extrapolate the power of 3rd harmonic or 3rd order intermodulation distortion at an arbitrary input power?

I'm trying to understand how to interpret 3rd Order Intercept (OIP3) specifications, and whether or not I can use them to extrapolate performances characteristics, other than just as a measure of ...
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### How to simulate and fine tune vacuum tube clipping behaviour for guitar overdrive?

I am looking to create a guitar distortion pedal in which the clipping is similar to that of a vacuum tube but should be tunable. That is, how do I make a circuit in which I can fine-tune its non-...
743 views

### Distorted square wave

I connected a BK Precision 4017B waveform generator to a Rigol DS1054 Oscilloscope. BNC ⇽ Co-Axial-Cable ⇾ BNC. 8 MHz square wave generated. Square wave looks rather distorted to me. See image below. ...
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### Distortion in a negative channel of the differential amplifier THS4505

I designed a single-ended to differential signal amplifier using a tool provided by Texas Instruments: The source signal passes through a voltage follower (OPA810IDBVR), so the output resistance ...
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230 views

### How do I calculate THD?

I want to calculate the total harmonic distortion of the signal using this graph and formula. The formula is taken from this page: Calculating harmonic distortion First Question: So my problem is to ...
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### What can cause these CAN signal distortions?

I occasionally observe signal distortions on CAN H, CAN L, and so also the differential signal. It is causing the microcontroller (dsPIC33) to report so-called Invalid Message Receive (IVR) errors. ...
1 vote
159 views

### Efficient method of measuring total harmonic distortion

I have been trying to create a set-up for measuring (estimating) the reported total harmonic distortion of an op-amp. (Please don't ask why I don't use a spectrum analyzer because I have been assigned ...
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1 vote
102 views

### LM393 dual comparator outputs are not the same

I applied the same signals to both inputs of the LM393P double comparator. The number 2 comparator output gave the expected result (first photo). However, when I apply the same signal to comparator 1,...
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1 vote
114 views

### My DIY tube amplifier distorts more than I planned

I have built a JTM145 clone. The original amplifier is clean and distorts when the volume is turned up, but my own copy of that amplifier distorts at low volume at the second 12AX7 tube from pin 7 to ...
286 views

### The input to the gate of an N-channel MOSFET is a pulsed signal but I am getting a ramp signal

I am trying to generate an output voltage of minimum 30V and maximum 50V, current of minimum 10A for a load of 2-10ohms using a MOSFET. I am connecting an NPN transistor's collector to the gate of the ...
2k views

### Why am I getting heavy output distortion from a BJT amplifier when driving an 8 ohm load?

Hello electronics professionals and enthusiasts! Software engineer mingling with breadboards and discrete components in his spare time here. I'm trying to build a simple BJT amplifier for my electric ...
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1 vote
96 views

### Pspice: FFT and distortion in output file does not coincide

I don't understand how Pspice calculate the distortion factor of a signal. I have this 1kHz output signal from an amplifier, and here is the FFT with 10 montecarlo simulation (zoomed): In the "...
131 views

### Why are the phases of a distorted sine wave always these four values?

In this image I show how I distorted a sine wave with three defects in the transfer function, similar to what you might see in a real transistor or tube circuit. I did the FFT on it and the extracted ...
225 views

### Why does my spectrum have humps?

In a fun experiment I used an Applicos ATX7006A 18 bit AWG to generate a 1 kHz sine wave and used an Analog Devices AD7671 16 bit ADC to digitize the waveform, then coherently captured the digital ...
1 vote
57 views

### Tube preamp overdrive question

Is it possible to add an overdrive gain pot (instead of just simply a bypass switch) to a preamp tube circuit? I am designing a new amplifier, and I want to include an overdrive/distortion option to ...
1 vote
154 views

### Generalized Memory Polynomial in Digital Pre-Distortion

I am currently trying to understand the concept of Generalized Memory Polynomials used in Digital Pre-Distortion and I wanted to seek some answers for some questions that were bothering me. The form \...
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244 views

### Name and cause for phenomenon in microphone preamp output as seen on scope screen

What might cause 1 kHz sinusoidal signal to change such as seen on the screen? How is this phenomenon possibly called? I have quite a lot of hand microphones with built-in opamp preamp and electret ...
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2k views

### What is causing the distortion in the negative cycle of this push-pull speaker driver?

I'm trying to build a unity-gain push-pull output stage to drive a small ~8 Ω speaker (measured DC resistance is 7 Ω; I don't have a datasheet for it). This is for use with a single rail battery ...
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228 views

I'm trying to solve the VAS (voltage amplifier stage) loading distortion in a three-stage amplifier. Excluding the input stage (called IPS in the circuit below), here is represented a typical VAS ...
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1k views

### I designed and built an op-amp using 4 NPN and 2 PNP BJTs. What are the pros and cons, and how can it be improved?

There have been some questions asked recently about op-amps, and I was curious to see how to make one with just NPN and PNP transistors. I did a simulation in LTspice and it seems to work pretty well, ...
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1k views

### Output signal distortion from op-amp

I am currently using a TLE2144, and the input signal of 600 kHz, 4.5 Vpp is generated from a function generator. Using a voltage follower with TLE2144, I was able to get an output of 4.5 Vpp with an ...
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137 views

### What causes the large THD increase measured after the output resistor in this op-amp stage?

I'm designing an audio mixer and took good care to create a relatively low THD signal path. At the final output stage I'm measuring a a THD of 0.06%, (10 Vpp, sine @ 1 kHz.) This is measured directly ...
• 1
408 views

### Unexpected non-linear response of operational amplifier

I have a resistive sensor that I'd like to use to generate an amplified voltage in a small range. I'd also like to shift/offset that range up and down with the use of a DAC to kind of "zoom in&...
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348 views

### Does a resonant peak produce a distorted wave form?

Context I am re-enforcing my understanding of the frequency response. From 1, I understand that, In an audio system, [the frequency response] may be used to minimize audible distortion by designing ...
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### 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 ...
830 views

### Square wave distortion at low frequencies, high-pass filtering, AC coupling

This is an update on my previous question. As Hearth suggeste, I changed to DC coupling on my scope. This is what I got: That's a clear change. Not a perfect square waves but I guess it is because of ...
828 views

### Square wave distortion on low frequencies

I have this old Soviet low frequency sine and square pulse generator "G3-36A". I ran into an interesting problem. When I try to generate square pulse under 100Hz I get a distorted wave. ...
883 views

### I'm desiging a class AB amplifier with class A preamp, what are the problems with my design?

I'm attempting to design a class AB guitar amplifier with a class A preamp. I'm a novice and this is the first actual project I'm attempting. What are the possible caveats, as well as my choice in ...
1 vote
385 views

### Discrete LM 741 using transistors only

I read how to build a discrete LM 741 op amp here. I tried to simulate it in LTspice: When I increase the sine wave frequency to make it operate at a higher frequency (10kHz,) the square waveform ...
1 vote
451 views

### What happens to a signal when it passes by diodes that are connected antiparallel to ground?

What are diodes 1 and 2 doing in this schematic? This is the schematic for a distortion guitar pedal. Why doesn't all the current flow to ground through diode 2? How does diode 1 have any effect if ...
2k 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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### 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 ...
396 views

### THAT1646 Distortion on output signal

I am working on an audio project using the THAT1646 balanced output driver (project is a hi-fi mixer for studio insert gear). The project uses a bipolar +/-15V supply. I am experiencing distortion on ...
149 views

### Waveform distortion with high ohm resistor [closed]

I have a problem that waveform distorted after adding high ohm resistor, (second figure shows that resistor voltage which doesn't follow of input pulse (yellow). So I added Darlington pair right after ...
1 vote
129 views

### Extremely basic guitar amplifier

I've been attempting to make a very basic guitar/condenser microphone amplifier for a long time, and I think I'm getting close (this is the first time I'm reaching out for help on the matter). I'm ...
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857 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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### What is the relationship between power supply rating and audio amplifier power rating?

I use many different types of Class D amplifiers in my designs. I am aware that the rated audio (RMS) power (with typical 10% distortion) relates to a sine wave which is not typical of music and audio ...
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5k 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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1k views

### Choosing an opamp for the amplifier stage of a signal generator (uses AD9833) [closed]

I am currently on a project to make my own signal generator for use in testing circuits etc. I have based it largely on a tutorial here: https://www.allaboutcircuits.com/projects/how-to-DIY-waveform-...
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537 views

### What actually causes the distortion in the output wave due to an Astable Multivibrator?

I've witnessed that the output square wave from an astable multivibrator using two BJTs has its edges rounded during the rise up time(just as it is seen in fig. 1). Across resources, I've come to know ...
116 views

### Why does this oscillator not work with a voltage less than 9 V?

By chance of my research and simulations and various tests, I found the diagram of an oscillator with strange behavior. All the oscillators (quasi) that I have encountered work whatever the supply ...
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1 vote
664 views

### Add negative feedback to this 2-stage amplifier

I am designing this 350mW 2-stage amplifier. The amplifier has only a voltage amplification stage Q2 biased with a current source Q1+Q3, a buffer Q6 and an output stage Q4+Q5. The input will be an ...
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2k views

### Is it possible to reduce distortion in a common emitter amplifier?

I am designing a common emitter amplifier for educational purposes. I work in a different engineering field so please bear with me. The gain of the circuit is around 26 (enough for my purpose), but ...
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358 views

### DIY function generator with an operational amplifier

I am trying to make my own function generator. I will make it with adjustable frequency and peak voltage but for test reasons I'm simulating a constant frequency one. My output has distortion which I ...
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124 views

### How to reduce distortion in a TPA3110D2 amplifier?

I bought these cheap amplifiers (2x15W TPA3110, the red ones with four caps and 4 inductors.) They sound good at normal volumes but then distort at high volumes. When I increase the input voltage, it ...
624 views

### wien bridge oscillator distortion

I built simple wien oscillator. How to reduce distortion of the sine wave? Leads was as short as can be, soldered "Manhattan style". Tried 2x KD305D power supplies as well as split battery ...
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### Inducing an intense varying magnetic field with a coil and audio amplifier

Disclaimer: I'm computer scientist I want to test a system described in an old (~1990) french patent and experiment with it if it works. The system requires to generate an "intense" varying ...
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### Class AB Amplifier - Weird oscilloscope output

I have built this little kit for a class AB Amplifier. This is the schematic if you do not want to follow the link It works fine, I can hear decent sound. I then tried to check the output with an ...
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