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Pure power from Pioneer

Symmetrical amp design for superior sound quality Why let your amp be the weak link in your audio chain? Pioneer has gone to extreme lengths to ensure that you'll get exceptional power and performance in your vehicle with the Stage 4 PRS-A900. This precision-built 4-channel amplifier was designed from the ground up to deliver rich, audiophile sound quality for the mobile environment.

Extreme accuracy

Pioneer capacitor

The PRS-A900 produces 50 watts RMS by four channels, or 100 watts RMS per channel in 2-channel mode. Independent power supplies ensure that both channels get the juice they need, even when there's heavier demand on one channel than the other. Pioneer developed their own power supply capacitors to keep output smooth when you're driving the amp hard. And the circuit design exerts tight control over speaker cone movement for extreme accuracy.

Bad vibrations

Copper mounting plates for transistors

Vibration is an amp's worst enemy — it can cause distortion and shorten an amp's life span. Pioneer developed its "H" style chassis to absorb incoming vibrations and protect the internal components. The PRS-A900's power transistors are installed on copper mounting plates to further shield them from vibration and noise. Heavy-duty, gold-plated block terminals accept power, ground, and speaker wiring.

Pure sound

Translation? The PRS-A900 is all about low noise and high performance. If your goal is pure sound quality, this amp will give you the most accurate reproduction possible.

Pioneer's Stage 4 System

Check out all the products in Pioneer's Stage 4 System, including receiver, speakers, subs, and amps.

Product Highlights:

  • 4-channel car amplifier
  • 50 watts RMS x 4 at 4 ohms (50 watts RMS x 4 at 2 ohms)
  • 100 watts RMS x 2 in bridged mode (4-ohm stable in bridged mode)
  • CEA-2006 compliant
  • preamp inputs and outputs
  • independent power supplies for right and left channels
  • proprietary power supply capacitors
  • "H" style chassis shields interior components from vibration
  • fuse rating: 25A x 2
  • signal-to-noise ratio: 108 dB
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 15"W x 2-5/8"H x 11-1/8"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Pioneer Stage 4 PRS-A900 Reviews

Average Customer Review:

5 Reviews

Pioneer A900

Written by: Bill from 60178 on March 25, 2015

Crutchfield Customer Review (What's this?)

I am using this amplifier to run a pair of A/D/S 346is separates. Tweeters and JBL T030 domed midrange on one A900. I have another A900 bridged for my mid bass woofers for the ultimate 3 way system. I can not say enough about this Pioneer amp! It is flawless in its musical reproduction and it has endless power Way Under Rated!! I have had Linear Power, Zapco, PrecisionPower and these Pioneer amps are by far the cleanest amplifiers for front speakers I have ever heard in my thirty years of being an audiophile. Thanks pioneer and Crutchfield for taking care of us audiophiles all these years!! Thank You, Bill L.

Pros: Made for my Pioneer DEXP99RS. Heavy construction and copper to block interference. Definitely not it's rated 50x4. Louder than my Zapco Studio 150 and that's supposed to be 75x2 and its under rated. Not louder but close to the Linear Power 2202 I had on separates before new head unit. Old head unit was Alpine 7949 with A/D/S passive crossovers. No need for passive crossovers with Pioneer head unit!!

Cons: I don't think there is any!! Maybe size


Written by: Bekir. from Arizona on December 27, 2014

Crutchfield Customer Review (What's this?)

I had JL audio 900/5 running to front and rear focal 165 KRX2 components. I felt sound was not solid enough and I replaced the amp with this PRS-A900. Now I have the true sound from my speakers.

Pros: True 50 watts per channel RMS power.

Cons: Made in China!!!

Truly Hi End Amp

Written by: LCKY from Fairfield, CA on June 9, 2014

Crutchfield Customer Review (What's this?)

This amplifier is amazing! The soundstage is super wide and realistic. Every detail in the music is revealed. The sound of vocals are very natural and precisely. The sound of brass instruments are very real. The best amp I ever had. Also, the power output is amazing! Only 50 watts rms and I can believed how it sounds. Super recommended!!!

Pros: No internal crossovers!!! Just a clean output, like my home audio amps.

Cons: None!!!!

Best of the Best - PRS-A900 4ch amplifier

Written by: Gee B from USA on December 1, 2012

Crutchfield Customer Review (What's this?)

The A900 is a rare, teir one audio component. Dynamic, detailed and clear discribes the sound. Its built to last as the chassis is robust. The P99RS head unit radio and several A900 amps is a declared investment. Its not for everyone, however if you have the means its worth your while to audition some of the very best on the market.

Pros: A high current, dynamic, revealing, effortless, 4 channel audio amp.

Cons: High price, 15lbs weight x 3 for a total of 45lbs when installed in the front trunk of a 911 (993). - it's OK....

Pioneer Stage 4 PRS-A900

Written by: Lynn from Mechanicsburg PA on October 12, 2009

I have this amp powering up the Pioneer Premier P800PRS head unit. This
combination along with JBL component speakers is the best sound in a car
audio system I have ever heard. Audiophile quality is the comment my
installer made. Everyone who has listened to it is amazed. If you are really
into listening to music, you cannot go wrong with this investment. Believe
me at this price,it is an investment. The only draw back is the price.



Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier with attached terminal covers
  • 11 Plastic wire ties (Length=4")
  • 4 Self-tapping screws (4mm x 18mm)
  • 4mm Allen wrench
  • 2mm Allen wrench
  • Owner's Manual
  • Warranty sheet

Product Research


Pioneer PRS Series: The Pioneer PRS series amplifiers cleanly amplify the music signal, free of distortion or added color. PRS amplifiers feature separate left and right independent signal circuitry that eliminates signal interference between the channels, and achieves excellent channel separation throughout a wider frequency range.

High-grade Circuitry: The PRS-A900 is built using high-grade circuits and parts, resulting in distortion-free sound quality, vibration elimination, and enhanced stability. Some of the technologies include:

  • Left/Right Independent Power Supply: Large, independently mounted DC-to-DC converter power supplies direct electric current with superior stability and effectiveness. The DC-DC power supply is mounted away from the amplification circuitry and isolated with dividers to prevent jitter noise and to improve the signal-to-noise ratio.
  • Filter-less Design: The PRS-A900's filter-less design means there are no built-in crossovers for the purest sonic reproduction possible.
  • Current Feedback-type Amplifier Circuit: Current feedback-type circuitry results in a high slew rate of 70V/µsec, allowing for precise output gain while perfectly following a sharp rise of input signal and wide range linear amplification of input signal for very low distortion while driving high output power.
  • H-shaped Chassis: The amplifier's H-shaped chassis and copper-plated power transistor mounts absorb external distortion-causing vibration 25% faster than conventional chassis designs. By stabilizing the amp and its internal components, audio reproduction remains faithful, accurate, and noise-free.

Independent Gain Controls: The PRS-A900 has independent 4-channel rotary gain controls. You can set the input sensitivity for the left front (channel A), right front (channel A), left rear (channel B), and right rear (channel B) from 0.4V to 6.5V. In addition, you can set the amplifier for 2-channel or 4-channel operation, depending upon how many inputs are connected.

Beat Frequency Control: If you hear a beat while listening to an AM radio broadcast, you can change the position of the BFC switch (located under the Pioneer badge on top of the amplifier) with a small flathead screwdriver.

Connections: For a clean installation, the amp's connections are located on the ends of the amplifier under removable terminal covers. The power and speaker connectors all have slots that allow you to secure the cables with the supplied 4" plastic wire ties. The connections include:

  • Left Side of Amp:
    • Input: stereo RCA jacks for line-level input signal
  • Right Side of Amp:
    • Right Channel Speaker: set screw terminals for front and rear channels capable of accepting up to 12 gauge wire
    • Fuses: two 25A ATO fuses
    • Power: set screw terminal capable of accepting up to 4 gauge wire
    • System Control: set screw terminal capable of accepting up to 12 gauge wire
    • Ground: set screw terminal capable of accepting up to 4 gauge wire
    • Left Channel Speakers: set screw terminals for front and rear channels capable of accepting up to 12 gauge wire

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Customer Q&A

1 question already asked

I forwarded your question to an Advisor and they responded with the following: The Pioneer Stage 4 PRS-A900 is a really great amp and at a fabulous price! It has high quality circuitry and gives really clean and accurate sound: low noise, high performance. Yes, it is well built and gives clean, crisp sound. I'd only recommend going another direction if you have speakers that are less efficient or need more power. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  Oct 31, 2014 ]  Staff