An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is defined as a circuit that has a power gain greater than one.An amplifier can be either a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categorized in different ways. One is by the frequency of the electronic signal being amplified. For example, audio amplifiers amplify signals in the audio (sound) range of less than 20 kHz, RF amplifiers amplify frequencies in the radio frequency range between 20 kHz and 300 GHz, and servo amplifiers and instrumentation amplifiers may work with very low frequencies down to direct current. Amplifiers can also be categorized by their physical placement in the signal chain; a preamplifier may precede other signal processing stages, for example, while a power amplifier is usually used after other amplifier stages to provide enough output power for the final use of the signal. The first practical electrical device which could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Today most amplifiers use transistors.

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  1. R


    Hello and good day to all car audio .com family. So today I have a quartorigo prestigio class a amplifier for sale . I bought this about a year ago thinking I was going to use it for one of my projects but unfortunately my project needs a engine. So I guess time to sell this beautiful...
  2. J

    Memphis mojo m1212

    Will tma 360.2 work with my Memphis mojo. Just trying to find an amp capable of pushing this speaker.
  3. some dude

    Car amp used in home

    My folks have an old subwoofer in their home stereo. The plate amplifier on the back of subwoofer cabinet seems to have died. I was gonna buy a replacement but the replacement size isn't identical. I'm sitting on 2 subwoofer amps from my car. 1 300w @ 4ohm Alpine and 1 500w @ 4ohm Kenwood...
  4. M

    Aftermarket Amplifier With Stock Audio System

    Hello, I have a 2023 Mazda CX-5 w/ Bose. I want to know if there is any audio interface that can be used so that I can hook up a bass amp and subwoofer while using the rest of the stock audio system. If not what other options do I have like a line output converter(LOC) and or digital signal...
  5. Rocky213

    FOR SALE DC Audio 3.5k

    Barely used DC Audio 3.5k. Still got the receipt from 3 months ago. Ran on good electrical. 370 amp alt. Never dropped below 13v
  6. N

    Old school Kicker amp repair

    I have 3 amps that need repaired Kx800.4, Kx600.4, Kx300.4 All come on and play but have a buzzing, left channel comes and goes and a RCA input issue seems if I wiggle the connection in n out it plays fine for a moment
  7. Chrisefta

    alpine 3522 amp

    I Found an Alpine 3522 amp but no manual to go with it, and was wondering what info was out there, and how good they were. My dad said it still works but, he couldn't recall anything about it.
  8. crxsir121

    FOR SALE Zapco Z-1KD II Subwoofer amp with Remote Gain Knob

    Zapco Z-1KD II Subwoofer amp with Remote Gain Knob. $350each/Firm no trades... I have Two of these amps for sale... Features and Functions Mono Class D Linkable, bass amplifier, Stable into 1 Ohm (2 Ohm w/2 amps Linked/Strapped) PWM MOSFET power supply 24 dB Variable low pass (LPF) crossover 12...
  9. Ishaboie21

    What sub and amp kit should I buy?

    Looking at picking up a 10" Kicker L7R 4ohm sub, but wondering what amp I should get to pair with it, and if it's worth getting a 4ohm or if I should just get the 2ohm to make life easier. I have a 1997 Acura Integra that I've been moding to be a daily driver for the past year, and want to add...
  10. E

    Engine whine - Desperately need help

    I've posted about this topic a couple times already, but I have yet to find a solution. I installed an after market amplifier to power my mids and highs. I already have a sub amp that isn't having the same issues. My stereo is a JVC KW-M780BT. The amplifier powering the whine is a Infinity...
  11. R

    Infinity Kappa Five Amplifier Advice

    Back in 2009 I purchased an Infinity Kappa Five amplifier That looks like the picture here: My current Kappa Five (LINK) Due to a possible grounding issue 3 weeks ago, I get to replace it. I can't be too mad, it lasted 14 years. :) I found one of these new in the box for $299 The...
  12. E

    Speaker Buzz After Installing Amplifier

    I just installed a factory refurbished Infinity Refrence 3004A 4-Channel Amplifier. I have the speaker connected to the amp with 14 guage ofc speaker wire, the power and grounds are 4 guage ofc. I tried to test the first speaker, and there's a constant buzzing independent of stereo volume. The...
  13. gagewill

    Subwoofer Popping at High Volume, Overpower Light Turns On

    I am rather new to car audio so excuse my lack of expert vocabulary. I installed a single 10 inch subwoofer box, and all new JL door speakers and dash tweeters into my 2020 Silverado 1500. Everything played great for awhile but I started to hear a popping / scratching sound when I turned the...
  14. unixnerd

    Good amplifier to drive a pair of small subs?

    I'm adding subs to my 2003 BMW Z4. I'm an electronics engineer but don't really play with audio much. I'll be using the factory subs which are 2 ohm. I can easily get the audio from the existing rear speakers and feed it to the amp. I'd like the audio feed to turn the power on at the amp if...
  15. finnmorgan

    amplifier issues

    I have bought a car with a very professionally installed Kenwood system from the early 2000s I assume. The issue i'm facing is in the Kenwood KAC-8404 Amplifier. For some reason the A-channel only output on the right speaker. The mono switch forces audio to the left channel and so there is no...
  16. E

    Mg marvel r bose amp wiring help

    Hi. I will be trying to hook up an amp and subwoofer in the Mg marvel r with the Bose sound system. Does anyone happen to know which color the +- on left and right rear speaker is?
  17. E

    COMPLETED JVC KW-Z1000W, JL Audio XD 700/5 v2, Wavetech Link 8

    FS: JVC KW-Z1000W 10.1” floating head unit Condition (1 being worst - 10 being best) 9.5 JL Audio XD 700/5v2 5ch amp $325–Free shipp——SOLD Condition (1 being worst - 10 being best) 9 Wavetech Link 8 Line output converter Condition (1 being worst - 10 being best) $90–Free shipping...
  18. D

    What fuse for amps power cable?

    Hello guys, I bought today a 4 channel TRF M600.4AB amplifier and dont know what fuse to use for power cable. On the internet i have read that because my amp has 2 fuses 40 amps each, i have to use a 80 ampere fuse. But my amps manual says that i need to use a 40 ampere fuse. What is the right ?
  19. D

    8 AWG or 4 AWG for amps power cable?

    Hello, I want to buy a 4 channel TRF M600.4AB amplifier (600 watt RMS, 1200 watt max) and connect to it a 12" TRF VLSW122D2 Subwoofer (250 watt RMS) and 2 front JBL Stage 2 604C speakers (6.5'', 45 watt RMS each). Should i use an 8 AWG power cable to my amp or an 4 AWG? Also what gauge wire...
  20. D

    45 RMS speakers to 80 RMS amp per channel

    Hello, I have a TRF M600.4AB amplifier which power is 80 watt RMS per channel (at 4 ohms) and i want to connect to it my front speakers (JBL Stage 2 604C) which are 45 watt RMS and 4 ohms. Is this possible or the speakers will be blown up? Do i necessarily have to buy new speakers above 80 watt RMS?
  21. D

    Is my battery enough for adding an amp?

    Hello guys, I own a Mercedes A 140 W168 and i want to install a 4 channel TRF M600.4AB amplifier (600 watt RMS, 1200 watt max) and connect to it a 12'' TRF VLSW122D2 Subwoofer (250 watt RMS) and 2 additional speakers on car's shelf (85 watt RMS each). So the music will be performed by 6...
  22. D

    Will the sub perform good?

    Hello guys, I want to buy a TRF M600.4AB amplifier (4 channels, 600 watt RMS max, max RMS power 4ohm 80W*4, max RMS power bridged 4ohm 300W*2) and a TRF VLSW123D2 Subwoofer (12'', 350 watt RMS, dual 2ohm voice coil) for my car. And i want to connect the "2 voice coils" of the sub in series (so...
  23. R

    (1) Sundown ZV6 2-OHM 12" 2500W RMS - Suggestions on Automotive Electrical Help and Amplifier Recommendation Needed

    I currently own a 2000 Chevrolet Cavalier that I am currently building a subwoofer install in. My complete and current installs: New Kenwood KDC-BT378U radio with built-in speaker amp, All new door and deck speakers. (COMPLETE) Big 3 Kit, Mechman 270 AMP Alternator, (1) Sundown ZV6 12" 2-OHM...
  24. D

    Help identifying what kind of amp this is.

    I know it’s a 2 channel amp but there is no brand name on it and I don’t know how many watts it is. I need to know what kind of amp I have if anyone can help.
  25. R

    Upgrading Electrical For First Time?

    I just purchased a 2000 Chevrolet cavalier LS 4DR. I am going to be purchasing (2) Sundown X 12 2 ohms (1500 watts a piece) and (1) Crescendo Bass Clef 6000W Amp In the next coming weeks. I will be custom building my box. I was wondering what electrical upgrades I will need to power this system...
  26. Mirza54000

    Audison lrx 2.9 in Protection

    Hi Guys, I just bought this Audison lrx 2.9 amplifier. The amp is wired correctly. Trying to run JBL 1220D (2ohms per coil) . Connected the positive to speaker left positive and negative to speaker right negative. Ground is connected to NEGATIVE and Battery to POSITIVE. Switched between mono...
  27. J

    Help with simple 12V, Ground, & Remote Wire Connections

    I have no idea how I am supposed to put my wires in here (third pic) with that metal thing that seems to be in the way. Is there a certain connector or adapter I need? If so please help and tell me what I need to get? This is the only help I need. Thank you.
  28. 8

    COMPLETED 2 Memphis Belles 16-MC600Ds and 1 Arc Audio 300.4

    Selling 3 Amps. 2 Memphis Belle 16-MC1300Ds one in perfect working order $350 plus shipping obo, the other channels 1, 2 and sub work channels 3 & 4 do not. Believe has possible bad input stage had estimate of $125 to fix. Will take $125 plus shipping obo. 1 Arc Audio 300.4 in perfect working...
  29. Manu

    Amplifier TOXIC TX 1600-N

    Hello guys, i'm new on this forum and i have a question for you. I'm using 2 speakers JBL CS1214, 1000w peak, 250w RMS each. These speakers are amplified by a TOXIC TX 1600-N. The question is: can this amplifier run on 2omhs in bridge ? I was searching about this amplifier and i didn't found...
  30. H

    COMPLETED Cadence A7+HC Ultrashock Amplifier - $250

    Cadence 1200 Watt A7+HC Ultrashock Amplifier - $250 For sale, used Cadence amplifier, puts out 1200watts Specs: Mono Block 500W RMS x 1 @ 4 ohm 800W x 1 @ 2 ohm 1200W x 1 @ 1 ohm 24dB Low pass adjustable crossover 18dB adjustible Subsonic Filter RCA preamp line out 8 volt line input voltage...
  31. D

    Recommend me an amplifier for my car & speakers

    Hello guys, I currently have Opel Astra 3 door car, which is pretty small car, and wanted to upgrade the audio system, bought a good Sony CD player with bluetooth, and those speakers - Hertz DSK 170.3 & Hertz CX 165, they are rated from 80W to almost 200, they have different Watt ratios so my...
  32. T

    Input sensitivity Question

    Ok so Im getting audio single to my amp from my rear speakers to a loc but Im wondering what should my input sensitivity be set at? 100mv-2 or 2-8 from what I hear you can just see what one works best when it's all set up.
  33. I

    Subwoofers get quite then loud again

    hey i have a simple question with Hopefully a simple answer now the setup I have going is not practical I know i know that I don't have them running in a efficient way but any how I have taramps hd3000 1 ohm to a power acoustic mofo 122x dvc 2ohm @ 4ohm and a rockville db15 running a power...
  34. M

    Car Audio System Keeps Killing My Battery

    Hello I’ve had my audio setup for a while now with no issues until last week. Went to leave my house and car won’t start because the battery is dead. Figured I had a bad battery because it was pretty old so I got a new one. Next day battery was dead again. So I unhooked my 2 amps and jumped my...
  35. Jgrif593

    Monoblock Amp with Two Sets of Terminals wired Parallel

    I have a Skar RP-800.1D, it is a monoblock with 2 sets of speaker terminals. I know that this is for easier wiring/ more space for wires. My question is when I wire this into my DVC sub, can I just run + to +, + to +, - to -, and - to -, and would this end up as parallel wiring? -For any...
  36. G

    Avalon 2005 headunit replaced - anyone have data sheet/specs for wires on the amp under the passenger seat?

    I put in a Kenwood carplay head unit years ago and it's worked fine. I have the JBL system and I use a Metra TYTO-01 JBL Amplifier Interface Harness to go from high level speaker outputs on the kenwood HU to the Metra harness which then goes to the factory radio harness and feeds into the...
  37. Hags222

    Basic question about calculating RMS and total wattage of my set up

    This question may be quite straight forward, but I cannot find an answer anywhere. I am new to this forum but I found the formula to ballpark estimate my total amperage. I do not understand one part. When you calculate this, do you add up the total RMS of the amplifier AND the subwoofers it will...
  38. BassJunkie96

    COMPLETED Brutal Sounds Bs2.1 $250

    Hello, selling a brutal sounds BS2.1 Korean 2k amplifier. Its been very lightly used, and in great condition comes with all accessories including the Allen key's for the power and other terminals. It's a great amp its just time to upgrade to a little more power. This amp is .5 ohm stable but...
  39. R

    Seeking help in selecting an Amplifier

    I am having Infinity Reference 6530 cxf (Component) in the front doors and Ref 6532 ix (Coaxials) in the back door. Could you please let me know if amplifier is needed to these speakers.? If yes, kindly suggest a good amplifier which suits these speakers. Note: I need little more bass and...
  40. P

    Help! Amplifier max output for Speakers!

    Greetings to everyone! Guys, just a simple question regarding amplifiers. I bought a 500w amp, 2-channel bridge. So, do I have 500w on each channel (for 2x 500w speakers) or I should consider the sum of both (for 250w speakers)? I bought 2x speakers, for rear only (Alpine SXE-6925S, 6 x 9...