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S300 Amplifier

S300 Amplifier

From the deepest bass to the warmest, sweetest highs, the Stellar S300 makes any loudspeaker sing and is our most affordable stereo power amplifier ever.
Breathe new life into your loudspeakers with the Stellar S300, a full-sized, affordable stereo power amplifier that honors the music and controls your loudspeakers better than you ever imagined possible. The S300 combines the slam, linearity, and toe-tapping pacing of a Class D output stage with the warmth, grace, and rich inner detail of Stellar's Class A Analog Cell. The results are nothing short of ground breaking. Liberate a wealth of untapped energy trapped in your media library. Plumb music’s subterranean depths and finally hear the bass your speakers were capable of. Revel in rich layers of fine, full detail. Marvel at the deep, extraordinary, wall-to-wall soundstage. Effortless. Lush. Stellar.
Regular price $1,999.00 USD
Regular price Sale price $1,999.00 USD
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  • Design

    The Stellar S300 stereo power amplifier is a dual mono power amplifier capable of effortlessly driving demanding loudspeaker loads to concert levels. It combines the best of two worlds: ultra linear, high-current, Class D technology for the output stage; a discrete, Class A MOSFET based Analog Cell for the all-important input stage. The S300's rich, warm, and engaging sonic character comes from the Analog Cell. It's powerful, authoritative control over the loudspeaker stems from its high current, ultra-low impedance Class D output stage.

  • Application

    The perfect choice for just about any loudspeaker, the S300 slips into any system, surprising and delighting even the most discriminating Audiophile. Rated at 140 watts per channel into 8‎Ω and 300 watts per channel into 4‎Ω, the S300 has plenty of horsepower for even the most demanding loudspeakers. Your musical library will open up in ways you might not have thought possible, revealing nuance and detail covered up by traditional amplifiers.


    The S300 is an extraordinarily musical power amplifier rated at 140 Watts per channel into 8Ω and 300 Watts per channel into 4Ω. Power enough for even the most demanding speakers. The S300 design marries the best of two worlds: an ultra linear high-current output power stage with a discrete Class A MOSFET based AnalogCell input stage. Between them, the S300 delivers powerful, authoritative control over the loudspeakers, while maintaining a perfectly layered soundstage under the most complex musical passages. Designed by PS Audio engineer Darren Myers, who invested hundreds of hours of tuning, voicing, and perfectionist tweaking, the results are extraordinarily musical. Stellar amplifiers never draw attention to themselves, and are one of our highest value offerings in amplification, a rare quality in amplifiers of any price.

    • 2Ω STABLE
    • < 0.1% THD 20Hz - 20kHz AT RATED POWER
    • DAMPING FACTOR > 550
    • 13 LBS.
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    Specifications - S300 Amplifier

    Stellar S300 Stereo Amplifier

    Unit Weight 13 lbs [5.9 kg]
    Unit Dimensions 17”W x 3”H x 12”D (13"D w/connectors)
    Shipping Weight 16.5 lbs [7.5 kg]
    Shipping Dimensions 22”W x 8”H x 17”D
    Color Options Black
    Voltage Options
    (Factory set only)
    Japan 100V
    North America 120V
    Europe/Asia/Australia/New Zealand 230V
    Mains Power Inputs IEC C14
    Idle Power Consumption 13W
    Accessories Included US (NEMA 5-15P) (all versions)
    Schuko (CEE7/7) (230V version)
    UK (BS 1363) (230V version)
    Audio Inputs RCA (Unbalanced)
    XLR (Balanced)
    Speaker Outputs Copper base nickel plated binding posts (2 pair per channel)
    DC Trigger Input 3.5mm 5-15VDC
    Warranty 3 years parts and labor


    Gain 30.5dB +/-0.5dB
    Sensitivity for rated output power 1.01V
    Noise 1kHz@300 Watts < -100dB
    Input impedance Unbalanced 50KΩ
    Balanced 100KΩ
    Output Impedance 50Hz, 2.8VRMS <0.007Ω
    Damping factor 50Hz. 2.8VRMS
    8Ω >1100
    4Ω >550
    Frequency Response 2.8VRMS into 4Ω
    10Hz – 20KHz +/- 0.5dB
    10Hz – 50KHz +0.1/-3.0dB


    1KHz, 1W/4Ω <0.02%
    10-20KHz, 1W/4Ω <0.02%
    10-50KHz, 1W/4Ω < 0.05% (90kHz BW)
    1KHz, 37.5W/4Ω < 0.01%

    Output Power

    Both channels driven 120vac mains, 1kHz, 1% THD
    8Ω 140W minimum
    4Ω 300W minimum
    2Ω Stable for musical transients


    This is going to be fun!

    The sound is already coming alive… in fact, it's faaaantastic! I'm currently listening to Robert Cray, Strong Persuader (high rez FLAC file). The detail and punch are just what they should be. His voice is clear and centered, surrounded by nicely balanced treble and bass. Another wonderfully engineered recording and the Stellar GCD shows it off in fine fashion. The clarity has improved and the veil has lifted. Wow, this is going to be fun!

    Finding renewed enjoyment

    I find myself digging further back in my CD collection and finding renewed enjoyment in old favorites. Many are digitally mastered (or 20 bit remastered) from the time when that was a new thing. Many selections from Sheffield Labs, DMP, ECM, Telarc and GRP make for good critical listening. My previous impressions (vs my previous preamp and DAC) are reinforced: excellent bass extension, deeper front to back soundstage, more precise placement and crisp percussion.

    Fun stuff!

    Right out of the box, the S-300 presented a sound stage larger than previously experienced with the older Rotel amplifier. Control was tighter, base was tighter, and the overall experience tighter. After about 3 hours, I adjusted speaker placement to take better advantage of the expanded sound stage. Fun stuff! One thing surprising, the experience was not strained at all, the sound is very relaxed, not overly bright. After approximately 6 hours, the unit is settling in nicely, both vinyl and digital sources are benefiting from the Stellar. I have other systems to reference back to (not just getting used to the new sound), and am looking forward to reporting back as to how the burn in continues and settles in.


    Goodness! Despite the slightly lower power of the Stellars, I was able to get 90+dB levels in the (largeish) room. And, for the first time sans subwoofers, there was solid chest-impacting bass. Next up was Blue Nile's A Walk Across the Rooftops; Heatwave is a perennial favourite. Again, from the Olive, transferred to digital through the NuWave Phono Converter. Ooh - goodness, even on casual listening there was a bit more going on than I remembered. Now I have to drive away and do some errands, so the machinery is left playing Best of the Shadows - you know, there's a bit more going on in there than I'd noticed before, too. And, begum, there's actual bass. Bottom line - straight out of the box, these Stellars make my system sound better.

    Love the amp

    Love the amp and I'm gonna buy it. I found the sound open and detailed with LP vinyl and CDs . Detailed soundstage and very musical in my opinion. I'm a construction worker so my computer skills are kind of limited. My associated equipment is Primaluna prologue 3 tube preamp project Debut carbon turntable and phono stage. Otrofon 2m red cart, Emotiva Erc 1 CD player, Klipsch RF 42 tower speakers, and energy sub in a 2.1 stereo system and PS Audio power cables and Audioquest interconnects. Pretty basic system by High end standards but wow did Freddie Hubbard and Pink Floyd sound great. Eva Cassidy's vocals were so rich and real and Dire straights Ride Across the River blew me away.

    Simply amazed!

    About 8 years ago I bought the Mark Levinson No. 434 monoblocks. They went for $8000 the pair, and they looked and sounded as good as I'd come to expect for that kind of money. I was happy! They are still very good amps by today's standards. When I think about how much performance PS Audio has managed to put into a stereo amp that costs less than 20% of what the Mark Levinson's cost, however, I'm simply amazed. The S300 doesn't look as expensive, but it's performance leaves little to forgive. When I'm listening to the Stellar S300, I've found myself not thinking about any of that—just the music, with the S300.

    Amazing soundstage

    I'm not adept at audiophile descriptions so I'll keep this relatively short. I replaced a modded HCA-2 with the S300 and have been mightily impressed. Most noticeable has been the blackness and silence of the background. That might have been a function of the mods done to the HCA-2, which I did love but always had a slight hum. The S300 is dead silent. Amazing soundstage and definition between instruments. Perhaps slightly dry but not overly analytical. I'll take the amazing detail on well-recorded material over warmth hiding poor recordings. I have plenty of poorly recorded albums that I love, I still can listen to them with this amp. The trade off is that well-recorded material sounds unreal. I hear things I never heard before! I'm impressed, and the music sounds wonderful. Thank you! My system - JA Michell Tecnodec and PS Audio Nuwave front end, Emotiva XSP-1 preamp, PS Audio S300, Alon Mark IV speakers


    My impression in one word: stellar! The S300's performance is really outstanding. It's very energetic and crisp, has very decent control and momentum. What I like most are its amazing vivid clarity and detail, this is not the kind of slow, warm, laid back and dull amp. Yes, maybe it lacks the last bit of extension at both end of frequency extreme. It's a tiny little bit on the forward and cool side of neutral, but definitely not aggressive, artificial or edgy. It's textured and colorful with very wide soundstage. And the punchy bass! If this is the one and only amp I have in a desert island, I can live with it happily ever after. Sound wise, it's that good.

    Whole new ballgame

    I received my Stellar 300 Amp about a week ago. My system is modest: Cambridge Audio CXA 80, Cambridge Audio CXC transport, Ohm Walsh Tall 100's with 2.1 Anti Cables. The 300 replaces the 80 watt amp in the CXA 80 and is connected with low quality single end cables. (the balanced Anticables await the Gain Cell DAC still on it's way.) The 300 made an immediate difference in the overall sound of the system, beyond just the additional power. The Ohm speakers create a broad and deep soundstage, but with the 300 instrument placement and clarity were clearly improved. Bass was more specific and apparent while the mid-range was richer with greater texture. Treble seemed heightened as well, though without strident overtones. I listen mostly to jazz and classical pieces on CD and through Tidal over a Sonos system. The extra quality power showed enhancement with Tidal as well. I have to imagine with the Gain Cell DAC in place it will be whole new ballgame.

    Two thumbs up!

    The S300 delivers a non-fatiguing presentation, with excellent bass control, and gobs and gobs of detail, all emerging from a black background. And it does so even at very low listening levels (living in an apartment, ability to listen at low levels late in the evening is important to me.) With the Red Wine amp. I had the powered subs crossed over around 70 Hz, at a higher output, to augment the Red Wine's lower bass output. The S300 delivers such powerful, detailed bass that the powered subs are almost unnecessary. I eventually added the subs back in, but crossed over around 45 Hz, just to provide that low end that you feel almost more than you hear. Just to be clear, the subs are making up for the bass shortcomings of the open baffle speakers, not any shortcomings of the S300. I give the S300 two thumbs, way up! Anyone want to buy a Red Wine amp?

    Don't want to be the competition

    I will simply say Paul & his fine team have, what I truly believe is the best amp @1.5k that you could possibly hope own. I wouldn't want to be the competition @ 3k & have to take the S300 on! Every listen just brings smiles. Clarity, depth, balance, dynamic range, and this thing just doesn't seem to run out of gas! I have a pair of Magnapan 1.6 QR's with an SVS subwoofer, the S300 delivers slam & articulation, like I haven't heard before. I had the 1.6's rebuilt by Magnapan 1 year ago after 13 years of serious use, so I am confident they are up to the task. Okay, I did spin some superlatives, sorry. I will sum it up by saying I am totally satisfied with the S300 & would recommend it to all, save your coin, this amp kicks some very serious butt! Thank you Paul & everyone @ PS Audio!