Questions tagged [preamp]
A preamp takes in very weak DC voltages or audio or RF signals and amplifies them enough to be used by a more conventional amplifier. Input may be in microvolts and output maybe 1 volt RMS or peak. They are often specific to amplify DC, LF/audio, RF or microwave bands. No preamp can cover DC to microwave bands and have good parameters at both DC and RF without software offset and gain correction.
24 questions with no upvoted or accepted answers
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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 ...
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Dual antiphase electret mic preamp topology
I am currently trying to make a preamp for an electret mic pair, which are placed physically in antiphase. The main idea is to subtract one mic's signal from another and therefore boost the signal ...
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Help identifying a photodiode pre-amp PCB
Recently I found this PCB in a electronics junk bin. It's said that it's a photodiode preamp, but I was not able to find the datasheet or any information about the board.
Since the PCB looks neatly ...
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Guitar to iPhone JFET pre-amp circuit issue
I am following this tutorial to build a simple JFET pre-amp to connect a guitar to an iphone.
This is the schematic:
I have soldered the components as per the schematic directly onto the 1/4" mono ...
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Replacing trim pots with potentiometers?
I have been looking at and considering building the following circuit from Beavis Audio Research. Their explanation of the circuit:
Around 1965, Marshall introduced a few amps built around an 18 ...
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Cartridge loading in Rodec phono stage
I saw a very strange design of phono stage in Rodec MX180 consoles. 3 generations of those mixers (mk1, mk2 and mk3) have this phono preamp on board!
They have an input filter with 1nF cap then 220 ...
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Adding volume control between equalizer and power amp
I want to built an Equalizer preamp for my power amplifier(stk4141 II).The equalizer is "Rod Elliott (ESP)-Eight Band Sub-Woofer Graphic Equaliser".This circuit has input and output buffer ...
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Connection Abbreviations on my plate amplifier control board and amplifier board
I've been looking everywhere for a common list of abbreviations found on my plate amplifier boards. They're located on the board connections that tell me what wires do what between the tone control/...
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Changed TL072 to OPA2134 - high shelf cut on highs
So I've changed TL072 op-amp to OPA2134 on ART Tube MP V3 preamp. Everything is working except it appears that high-shelf cut is being created (~9 dB at 10 kHz) (measured with pro audio interface ...
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Suggestion about drag and amplify pulse
Following picture is Photodiode I/V pre-amp of my circuit
My target pulse from OPA356 output, which range is 15mVpp /130ns-width to ...
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Standards for measuring analog audio signal devices
I'm making a Analog Channel Strip for a project. I'm searching for standards that let me or give me an advice of how to measure Dynamic Range, THD and THD+N, SNR, Frequency Response and input/output ...
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Noise problem in preamp to digital processor
I'm building a guitar audio processor. I inherited this circuit from someone else's project. I am seeing a significant amount of noise on the input. I digitize the input using a 16b ADC and clip to ...
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Building a MEMS Microphone Monitor System
While I've never used a breakout board when building an electret mic, I have used the small Spark Fun 09068 and Cinimark admp401 boards for MEMS mics. They seem to work with a 9v battery box I built ...
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LM386 as pre-amplifier for electret capsule
Although I know the LM386 is intended as a power audio amplifier, I wish to know if it can be used as a pre-amplifier for an electret microphone capsule, as I intend to use it for that purpose. If yes,...
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FM receiver With LM386 - Need a Preamplifier
I am building a hoppy FM Receiver and I created the Preamplifier stage 1 and linked it with the LM386 Stage and it goes OK but The output sound from the Speaker is weak so I tried to do some ...
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Using diy lm386 preamp on standard commercial amp?
I have a small intercom-like device that has been siting around.
It looks something like this.
I suppose that inside is just a basic elect-mic and a button.
Also i have an power amp which i used to ...
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Signal routing to power amp LM1876 based on TS5A22362 SPDT
Has anyone ever used the TI's TS5A22362 CI to route audio? I though of implementing the circuit below on which I intend to use the same supply voltage to switch between normally closed and normally ...
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Additional gain with in-amp for nanovolt-scale pre-amp
Currently I'm designing a pre-amp for detecting nanovolt-scale(~100nV, <1kHz) signal for experiment. I need a final gain to be around ~100000. Since the magnitude of the signal is extremely small, ...
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High quality, low-noise, pre-amp circuit for condenser microphone (with phantom power)?
EDIT
Suggestions so far, and reference to another question indicate that a discrete FET based input stage, perhaps followed by a particular low-noise IC for a second stage, might be a good approach.
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AV Receiver playing music using RCA Analog input (AUX) from Mobile 3.5 mm stereo source
I have a pioneer AV Receiver VSX-832-K with RCA AUX INPUT "input (Sensitive/Impendency ) 200mv/47K ohm"
issue :
when i am trying to play music from mobile using 3.5 mm headphone jack using ...
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How To Make A Two-Channel Audio Mixer?
I'd like to make a 2-channel audio mixer. I'll connect one of the entrances to my phone with an aux cord. I'm going to put my headphone mic on the other one. I'll also connect a potentiometer to both ...
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Pre-amp connection problem
I am trying to complete the circuit shown above. I am having trouble as the ground connection is not clear to me. Please help me to complete that circuit.
And also tell me how to connect C5 ground ...
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Ultra low noise power supply for pre-amp
I have designed the following power supply smoothing circuit for my turn table preamp. This will be powered by a 24V 'wall-wart' type adapter.
I tried to combine a transistor/zenner diode voltage ...
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How to make a preamp that is ON when input is a MIC but OFF when a LINE level?
My question is very simple:
Is there a way to create a "preamp" circuit that is automatically ON when there is a MIC connected (for example, a desktop PC microphone) but OFF when there is a LINE ...
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