Alpine R-A90S

R-Series 6/5/4/3 Channel Hi-Res Audio Power Amplifier

Available In-store Only


Send an inquiry

Product Enquiry

  • This field is for validation purposes and should be left unchanged.


The all-new R-A90S is extreme and class-leading in every way. Beneath its sophisticated and bold design, brings a powerhouse of Alpine ingenuity and technical innovation to create an industry first ‘full-system’ 6-Channel Hi-Res compliant power amplifier.

Delivering serious amounts of power, the R-A90S has the capability to power an entire system with a subwoofer, or can be configured to power an array of 3-way high-end speaker systems with precision using the LP/HP/HP-H/BP crossovers. What’s more, power output is staggered with the capability to deliver different levels of power to each channel regardless of the system configuration.

With performance at the highest standard, the R-A90S has a dynamic range of up to 45kHz and a >500 dampening factor to deliver high power output with precision, as well as a superlative high-definition sound experience.




What is Hi-Res Audio?

You can now appreciate a higher sampling rate than in CD’s for the encoding and playback of music, it brings your favourite tracks to life with extreme clarity. Alpine’s painstaking engineering has delivered faithful audio reproduction from high resolution sound sources and recordings at 96kHz/24Bit or greater, they are optimised for high definition playback and breathtaking performance.

Why Hi-Res Audio?

Listening to Hi Resolution Audio allows you to feel every emotion and hear every nuance; every detail of your favourite artist’s original studio performance is reproduced to perfection. Hi-Res Audio provides absolutely no distortion for the ultimate listening experience.


Alpine R-A90S -

Versatile System Builds

The R-A90S features a staggered power channel layout that allows each channel to host different levels of power, compared to traditional, multi-channel amplifiers. This allows the R-A90S to effectively function as both a 3-way active amplifier and a 5-channel amplifier by delivering the power you need to the channels where you need it the most.

Now you can use one amplifier to either power an active 3-way sound system or use it to power your speakers and subwoofer without the bulk of an additional amplifier. With ground-breaking multi-functionality and high-power output, Alpine’s all new R-A90S R-Series amplifier enters a new world of Hi-Res sound.

Check out the video at the bottom of the page for more tips on how the R-A90S can take your system to the next level!


Alpine R-A90S -

All-new Advanced Digital Design

The innovative R-Series amplifier boasts an advanced digital design which unlike a typical Class-D amplifier circuit adds all-digital dual post-filter feedback loop for unmatched accuracy and control, while minimising internal noise.

Alpine R-A90S -

Extraordinary Damping Factor

The R-A90S R-Series amplifier produces an extraordinary damping factor of >500 for channels 1/2/3/4 and >500 for channels 5/6. This achieves precision control of cone movement at high power outputs with virtually zero distortion.


Alpine R-A90S -

Hi-Res Audio Compliant

The R-A90S is Hi-Res Audio certified and engineered to operate in an extended frequency range of 10Hz~45kHz. Furthermore, signal-to-noise specifications are at benchmark levels with 103dB for channels 1/2/3/4 and 106dB for 5/6.

Alpine R-A90S -

Precision Crossovers

The R-A90S is built for system flexibility and precision setup with its extensive crossover capabilities. You can set the HP/LP filters for a full system with a subwoofer, or use the HP-H and bandpass filters for an active 3-Way speaker system.


Alpine R-A90S -

Benchmark Sound Staging

The R-A90S is optimised for benchmark sound quality, as well as staging and imaging. Rivaling the industry with an incredibly low phase shift of 46° this superior phase curve ensures accurate and defined sound imaging.

Alpine R-A90S -

Accurate Sound Reproduction

Using the same exclusive technology launched in Alpine’s premium X-Series amplifiers, the R-A90S has dual “Sierra” post-filter feedback loops that correct signal distortion by making the output as close as possible to the original input.

Alpine R-A90S -


RCA and Speaker Level Inputs

The R-A90S is equipped with low-level RCA inputs, which can also accept high-level speaker signal inputs (via the optional KCE-SP2R). This allows for installation of the amplifier into virtually any aftermarket or OEM factory audio system.

Heavy Duty Gauge Terminals

The speaker and power cable terminals are conveniently located on the 6-channel amplifier providing easy and clean installation. The compact and robust design delivers lossless connectivity.


Alpine R-A90S -

Control Your Subwoofer

The optional RUX-KNOB.2 remote bass knob controller plugs right into the R-A90S amplifier, providing quick direct subwoofer control to make bass adjustments on the fly enhancing your listening experience. Does your system run two bass knob ready amplifiers? With the use of an additional accessory*, control the bass levels of both of your amplifiers with only one controller.

* Requires a 3rd party RJ45 Splitter

Alpine R-A90S -

Optimised for Alpine’s R-Series Sound System

Alpine’s stunning R-Series line of speakers, subwoofers, and amplifiers have a heritage of sound quality that can be heard from a block away. The R-A90S 6-channel amplifier is tuned to emphasise the characteristics of the R-Series speakers and subwoofers for a legendary R-Series experience. Visit the systems page to browse our range of systems packs.

Can’t find what you’re looking for? Give us a call at 02 4965 6899 and let us help you!

  • The boys were fantastic, so happy with with the service from start to finish.

    The boys were fantastic, so happy with with the service from start to finish. wouldn't go anywhere else. do yourself a favour and head into see them 1st, you won't go anywhere else. Thanks boys

    Tracey E.
  • Would highly recommend

    Would highly recommend didn't charge me anything for the checkup on the audio system since it was a small problem. 10/10 they're awesome.

    Robbie Y.
  • awesome service. reasonable pricing. I will keep going back there. recommend 100%

    been there a few times for stereo install, dash cams, light bars etc awesome service. reasonable pricing. I will keep going back there. recommend 100%

    Shannon R.
  • Couldn’t have asked for better service from the get go

    Had my 79 series landcruiser in there for the works - door pods, speakers, apple car play head unit, under seat subs, amp, gme UHF and a few other bits and pieces. Couldn’t have asked for better service from the get go, Anthony was a pleasure to deal with, and the guys done neat professional work on the job itself, highly recommend

    Ryan T.
  • love coming to Newcastle pro sound

    love coming to Newcastle pro sound. great install and great service, especially from Ziad & Anthony

    Peter H.
  • I will always be their customer while ever they are still operating.

    These guys are absolutely amazing. I have dealt with them for many years. Michael has always fitted my systems, he is great & very friendly. They have done lots of radio and phone systems in my car and they have always provided wonderful, prompt & friendly service. I have just been there again today as my iPhone cradle broke (after many years) and Anthony fitted a vent magnet for my phone, he was an extremely friendly, happy guy. I will always be their customer while ever they are still operating. The floor staff are excellent and Hannah at the front...

    Christine H.
  • Thanks Newcastle Pro Sound for going above and beyond on my car.

    Had new gear put in my Audi TTRS yesterday and when installing they came across a different electrical set up than usual. The installers and sales staff stayed back working late until 8pm on their own time without charging extra. The advice was good and quality of product is excellent. The first place I went for a quote gave me a feeling it was a load of crap to get me to buy the speakers that would give them the best margin and rip me off. So glad I went for a second opinion. Thanks Newcastle Pro Sound for going...

    Adrian M.
  • the team stayed back this afternoon to get it done for me - extremely appreciative of their efforts

    Great professional service, came in this afternoon for information about an installation, and the team stayed back this afternoon to get it done for me - extremely appreciative of their efforts and everything looks good and works great!

    Tom H.
  • I don't take my car anywhere else when it comes to audio electrical stuff.

    Great friendly staff, awesome service and reasonably priced product. I don't take my car anywhere else when it comes to audio electrical stuff.

    Eddie A.
  • Workmanship is awesome - no squeaks, rattles and a "as factory" quality - the workshop team is top end. Firmly recommended!

    Such a professional and courteous outfit! I was the typical high need customer armed with a bunch of unsubstantiated info from the internet.. Hannah knew an awesome amount about what I was looking for and when more info was needed, was honest and followed up on promises to get back to me in a time frame. Anthony understands what you need, knows his stuff and is great to deal with. Through the installation Anthony was a great help, inspected the install at handover with me, showed me how to use the tech! On top of that great support and aftercare....

    Chris D.