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REDGUM Black Series RGi35ENR integrated amplifier review

  • ‘Under promise, over deliver’. That’s always been REDGUM Audio’s primary motto – at least that’s the way I see it.

    On the wooden face of it, their key-locking entry-level RGi35 (AU$1100) is a no frills integrated amplifier, proudly made in the Dandenongs in country Victoria.

    It’s a dual mono design with which the user must balance individual left and right volume controls. Need both channels level-matched more easily? The auto-balancing remote control option adds AU$275 to the sticker, without which there’s also no soft/er start; an audible speaker thump is heard at power on.

    REDGUM’s over delivery doesn’t stem from the amplifier’s feature set but from its power delivery. Two MOSFETs per channel fed by a low voltage 160VA transformer are central to a circuit that’s high on current delivery and damping factor. The nominal 35 wpc rating is modesty writ large.

    And I should know: the RGi35 was my very first audiophile amplifier, long before I entered the review game.

    Each REDGUM amplifier ships with its own measurement report. A typical RGi35 nets 40 W RMS per channel with 70 W RMS per channel capability for when music gets hectic and short-term high-energy power bursts are required.


    The RGi35’s ability to call on serious reserves of transient power is precisely what had me invite REDGUM to partake in three-way amplifier stand-offs with Magnepan’s entry-level MMG floorstanders and KEF LS50 standmounts. DAR reader emails relating to amplifier matching for these two loudspeakers outnumber all other brands ten to one.

    The RGi60 deployed in each of those self-styled assignments has since enjoyed a long-term loaner residence at DAR HQ, the measurement report for which sees it double down on the nominal 60 wpc channel rating: 114.91 W RMS per channel with 267.50 W RMS transient power. Strewth.

    REDGUM Audio’s secondary motto might be ‘if ain’t broke don’t fix it’. Such philosophy has held the RGi35, RGi60 and RGi120 to only minor internal updates since first being introduced in the mid 1990s. ‘ENR’ (“Ian R” – geddit?) Signature versions were introduced in the noughties with only the RGi120ENR (review here) exhibiting significant external changes with its SineWave heatsink.

    In 2014 REDGUM notches up twenty-one years in the hifi biz. A coming of age that has Ian Robinson (‘Design Engineer’) and Lindy Gerber (‘Promotions Manager’) looking to reinvigorate their brand’s comparatively unassuming presence. To whit, they’ve opted to ride the zeitgeist by crowd-funding the first of their ‘Black Series’ range of amplifiers.

    “A new tack for a new generation of REDGUM amps that remain the same electronically! Once a REDGUM, always a REDGUM but indeed Chinese-made to REDGUM’s Australian standards!”, exclaims Gerber.


    Statlers and Waldorfs set to holler “Judas!” from the peanut gallery are reminded of REDGUM’s rather superb China-made-Melbourne-modded Sonofa’GUM 5500; Dylan going electric this is not.

    No doubt Gerber and Robinson drew on their experience in off-shoring the production of the Sonofa’GUM when mulling the Black Series – anniversary models for which the elemental REDGUM circuit design has been maintained. I’m told that Robinson has spent considerable time supervising quality control at the Chinese factory.

    Inside the all-new RGi35ENR a pair of MOSFETs still drive each channel’s output stage but the power transformer is bigger than its all-Aussie predecessor – a high voltage 100VA toroidal for more upfront grunt as well as an ability to better handle lower impedance swings.

    Getting speccy: 65 wpc into 8 Ohms, 80 wpc into 4 Ohms, 95 wpc into 2 Ohms. Numbers that leapfrog the average wood-fronted RGi35ENR’s 52 wpc steady state and 136 wpc transient capabilities.

    On price the young upstart undercuts the old timer by up to AU$600 (depending upon Indiegogo trigger-pull timing).


    Then there’s the ‘SineWave’ heatsink. Previously exclusive to the Australian RGi120ENR, it will be a fixture on ALL Black Series models, apparently to help maintain uniformity in the manufacturing process. Black Series editions of the RGi60ENR and RGi120ENR are coming down the pike.

    Far from just a cosmetic concern the heatsink lends this new RGi35ENR a presence that connotes serious business (and physical weight). Pop the lid and you’ll see the MOSFETs thermal pasted directly to its upper surface.

    With the aforementioned RGi60 still in the house the scene was set for a stand-off.

    With REDGUM’s permission I’m sharing internal shots of each amplifier. First up, the RGi60:


    …and here’s the Black Series RGi35ENR:


    Build quality on the Australian made unit feels a little more polished. I noted rougher screwhole drilling when popping the lid on the Chinese amplifier. However, its colour matching of RCA input and display LED on was a welcome improvement on its forerunner.

    Listening began with a pair of Zu Soul MKII loudspeakers and a Resonessence Labs Herus decoding Qobuz lossless streams.

    Audibly evident from the get-go was the RGi60 and Black Series RGi35ENR were quite obviously cut from the same qualitative cloth. The house sound of badass bass and solid amounts of acoustic mass could be heard from both amplifiers. Moroever, are these were two fundamental ways in which REDGUM’s Chinese newb trumps the Clones 25i ‘Gainclone’. The latter bests both REDGUMs on quicksilvery speed.


    The differences between the two REDGUMs were, at times, excruciatingly subtle. The RGi60 presented as a smidge softer with a drizzle of molasses to sweeten and thicken — this translated to player separation that’s less overt than the all-Black RGi35ENR. The latter’s more lit up top end puts it closer to the Clones’ lickity-split delivery of guitar plucks and cymbal shimmer.

    With D/A conversion that’s keener with decay and textural information at the front of the chain – Metrum Hex and Resonessence Labs Herus – the Zu floorstanders give the nod in a photo finish to the RGi60. Moving to the smoother INVICTA Mirus, my preference fell the other way.

    Over-simplifying, the all-Australian unit sounds warmer whereas the Black Series amplifier pushes presence region ‘crunch’ and crispness further under the listener’s nose.

    As a Zu-lander, the RGi60 is more adept at keeping Crazy Horse’s guitar shred in check whilst the RGi35ENR’s way with separation and transient attack better lends itself to Atoms For Peace’s cleaner outlines.

    It’s no surprise that the Magnepan MMG are incredibly popular. Their stateside RRP of US$599 positions them as one of the great hi-fi bargains of all-time. Whilst they’re no match for the Zu Soul’s tonal confessional, the MMG serve up an enormous wall of sound that’s big on macro-dynamics action and even more adept with micro-dynamic inflection. You’d have to move up to something like the KEF LS50 to attain comparable audio satisfaction from a box speaker.


    The Magnepan catch? You need power – and lots of it. More often than not owners are forced to sail against prevailing wisdom when dropping the largest percentage of system budget on a matching amplifier, especially when opting for a Class A/B solution over the generally more wallet friendly Class D.

    In offshoring production REDGUM have laid down the gangplank for super-affordable, entry-level Class A/B Magnepan MMG power. The new RGi35ENR easily holds its own when compared to the RGi60.

    To push hard into higher MMG SPLs, the Chinese 35-watter’s hefty heatsink means the fan cooling of the RGi60 just isn’t needed. I can trigger the latter’s protection circuit when pushing The Stone Roses’ “Begging You” to increasingly higher SPLs. The RGi35ENR isn’t tripped up easily. That alone nets the Black Series unit an easy point in the game of quantitative one-upmanship.


    Picking qualitative differences was tougher. The newcomer necks an aspirin to run with thinner blood than the RGi60. With MMG juiced by the RGi35ENR, micro-dynamics come on with extra citrus zest. Player outlines are more cleanly inked. Treble sizzle and to-the-sky aeration collectively alludes to a greater sense of detail; the RGi60’s slightly thicker tonal body and more rounded transients commingle to a thicker musical soup.

    For idealists who still demand local manufacturing, the more idiosyncratic wood-panelled fascia and key-lockable power, the RGi35ENR remains available at AU$1390 – but without the SineWave heatsink. It will eventually sit as the new starting point of REDGUM’s (soon to be christened) Amplifolia range.

    However, I can’t fault pragmatists for voting with their wallets for the far keener value proposition of the Black Series RGi35ENR. It’s the epitome of ‘more-for-less’ – another motto for this Australian amplifier manufacturer.

    Associated Equipment

    • VPI Scout 1.2 w/ Dynavector 10×5
    • PS Audio NuWave Phono Converter
    • Resonessenc Labs INVICTA Mirus
    • Resonessence Labs Herus
    • Metrum Hex
    • Aqua La Scala MKII
    • REDGUM RGi60
    • Magnepan MMG
    • Zu Soul MKII

    Audition Music

    • Atoms For Peace – Amok (2013)
    • Neil Young & Crazy Horse – Weld (1991)
    • The Stone Roses – The Second Coming (1994)

    Further information


    John Darko

    Written by John Darko

    John currently lives in Berlin where creates videos and podcasts and pens written pieces for Darko.Audio. He has also contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

    Follow John on YouTube or Instagram


    1. Not exactly the glowing review I was hoping for. Bought one of these on Indiegogo. Hope it matches well with my Harbeth p3esr. I was almost sick reading this: “Over-simplifying, the all-Australian unit sounds warmer whereas the Black Series amplifier pushes presence region ‘crunch’ and crispness further under the listener’s nose.” I was hoping the heatsink would bring out the bass more than described here.

      • I don’t think it requires gushing, over the top language when the results speak for themselves: the new one holds its own (and then some) against the 3x pricier RGi60. The new one is also more adept at driving Magnepan. When choosing which one to hold on to for longer and which to send back to Redgum, I’m clutching tight to the Black Series model. Does that help relieve some of your nausea? 😉

        • Thank you for responding, John. I didn’t expect gushing but “crunch’ and crispness further under the listener’s nose” is pretty explanatory of your true feelings about this amp. Words have meaning, especially when they’re thrown out there like that. I will never send back the Black because Lindy is a nice person and I respect the Redgum brand. I was expecting more bass presence for my little gems, the Harbeths.

          I don’t mean to insult your review but I think your real view of this integrated is clearly shown, subconsciously or not, between the lines.

          • Jim – I see my job as primarily one of describing what I hear. That way readers can make their own call. A personal preference wasnt explicitly expressed until my previous comment. I like the Black Series RGi35 more than the RGi60.

            Is it possible you might have inferred a negative vibe (from ‘crisp’ and ‘crunch’) because it’s not what you are looking for?

            • I love ‘crunch’ and ‘crisp’ but not ‘shoved under my nose’ at the expense of warmth and bass. I don’t know why you’re arguing this John; I am just relaying what you wrote.

            • Jim – if all you were doing were relaying what I wrote then I’d have no issue. My concern is that you’ve transposed a layer of negativity over what I wrote that certainly wasn’t intended at this end. You said the nature of my comment made you feel ‘sick’. That’s a bit more than ‘relaying’ what I wrote, don’t you think? That’s your reaction to what I wrote.

              I thought that ultimately expressing a preference for the new amplifier in my first reply might help clarify things. I haven’t unplugged the Black Series unit since the review wrapped. The RGi60 is back in its box.

              Yes, I did say that crispness and crunch were more upfront on the new guy but not at the expense of bass. You don’t like “shoved under my nose” – fair enough but that’s *your* preference, no? My intention when choosing such descriptors was to relay the sound of new amp compared to the old without expressing a positive or negative vibe. And yet you said claimed to *know* my true feelings about the amp. I’m merely pointing out that this is your inference and not my implication.

              Let me go with another example. The Voxativ speakers that I heard at the Newport Show this year lend music an ‘edge of the seat’ presence – they too shove things under the listener’s nose. Is that good or is that bad? The answer is: it depends on your preference. Some listeners will LOVE it, others will want something more easeful.

              Did you receive your RGi35 yet? And you’ve hooked it up to the Harbeths? Not much bass? Perhaps there’s an amplifier out there that will serve you better in that regard?

            • My apologies, John. I don’t know about Australia, but here in Canada, your ‘nose’ comment connotes a negative – a damning negative to be more exact. I’ve re-read and re-read your review and see that I overreacted.

              I’m looking forward to my first Aussie amp and one made by a company with a fine record.

              Sorry to have taken up so much of your time with my nonsense.


            • No problems Jim – I guess I should be more mindful of the way English might be interpreted in different parts of the world. 🙂

      • Either would be a good fit. You gotta ask yourself: do I want the wooden finish (and pay more)? Or do I want the large heatsink, better lower impedance handling and ever so slightly keener pursuit of detail retrieval (and pay less)?

    2. Look at the cheap RCA plug and cable used internally in both Redgum amp, I am so suprised and disappointed!

    3. Hi John

      Just received my Black series RGi35ENR and it is as good as you say. The best amp I’ve ever heard for 60’s rock. Guitars blast like they should and the bass rocks my little Harbeths with authority.

      One question. The highs and higher midrange are a bit harsh. Do you think that this is just a burning-in issue?



      • Tough to say really. It’s a quality that I called out in the review so perhaps you’re hearing that? What speakers are you driving?

        • My bad. Not sure if it hadn’t anything to do with it but had polarity reversed on the speakers, because my old preamp was inverse. Much fuller now and exciting. Or maybe it’s just me playing it all day, but the unit sounds great now.

    4. Holy Crikey!! Just got my Black Series 35 via Indiegogo. Wow! Thanks for steering me Downunder for an up top amp! Can’t imagine how powerful the big brothers will be.
      I am pairing it with Kef LS50s 🙂 with a MBP and HRT microStreamer for a source.

      …now if you could just convinence me to like Vegimite

      • You and me both PM. I don’t dig Vegemite either. Pleased you got satisfaction with the amp though.

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