Posted on 21st February, 2018


If you are posing the question “Redgum Who?” be advised: Redgum Audio is a quintessentially Australian audio brand. We take a closer look at the RGi35ENR amplifier which can trace its roots back to 1976.



Integrated Amplifier

If you are posing the question “Redgum Who?” be advised: Redgum Audio is a quintessentially Australian audio brand.

So Australian, it is as true blue as the Kangaroo, Sydney’s coat hanger bridge or having a Four'n Twenty pie with sauce at the footy.

Aussie identity and longevity are at the core of Redgum, the company.

The RGi35ENR amplifier can trace its roots to Redgum’s conception when from 1976 principal owner and designer, Ian Robinson, ran a natty hi-fi shop in Hawthorn, Melbourne.

After repairing an expensive UK amp, he turned to his tech employees and opined, “Fellas I can do better than this.’’

I remember the store.  I dropped off an Ariston RD11 turntable there for repair around that time.

Ian tweaked the bearing, and from that point on my RD11 was better than new.

I recall thinking how Ian Robinson was no ordinary tech. His skill level was way above the average.

22 years later, he had closed the shutters on Contemporary Sound Centre to focus on amplifier design and manufacture.

Robinson built an amp bearing the initials of the store, CSC. The actual model was called “The Enduro’’ because it ran MOSFETs, an output device deemed by him to be indestructible.

The first Redgum amp with the now iconic Redgum wood front panel was released in 1993. Ian registered Redgum as a company in 1995.

This sojourn down Redgum’s memory lane throws a spotlight on why the RGi35ENR sounds like it does and controversially, is designed the way it is.

Audio veterans know all about Robinson’s penchant for MOSFET technology. I am personally not so hot on MOSFETs.

Used well, they elicit an engaging musicality. However, that’s usually delivered with a colouration I call “The Dreaded MOSFET Haze’’.

The sound of the $2000 RGi35ENR ignites memories of MOSFET amps I have enjoyed in the past. These were hybrids with tube input stage and MOSFET outputs built by the US brand Counterpoint and released as its SA series.

I recall owning an SA12 power amplifier. Very musical it was. However, the sound was not wonderfully transparent, and yes, it was served up with the dreaded MOSFET haze.

The Redgum exhibits some of the same warmth, outright attack, and detail of the Counterpoints. The Counterpoints were like the Redgum - engagingly musical.

That is when they were working. More often than not, the Counterpoints were not.

They were notoriously unreliable. As were the brand’s SA series of gorgeous looking and wonderful sounding preamps.

So unreliable, International Dynamics the Australian importer at the time, dropped the brand from its portfolio. I owned an SA1 preamp and later, an SA12 hybrid amp.

Sample variations also plagued the Counterpoint amps. Depending on which batch or day of the week yours was made, it could sound inherently musical or just dreadful.

My preamp behaved perfectly and gave no reason for concern. However, the power amp broke, and no one seemed able to fix it. I put it in storage and decades later, Tony Moore, the amiable and talented owner of the Ambience loudspeaker brand, got it running again.

Needless to say, Counterpoint’s reliability issues were not caused by its use of MOSFETs and Redgum has an excellent reputation for the robustness of its models and first-rate after-sales service.

You will not find Trolls dissing Redgum about reliability on the usual hi-fi forums. Quite the opposite. It would be hard to imagine a gentleman like Ian Robinson and his thoughtful co-owner Lindy Gerber walking away from a service issue.

However, the Counterpoint connection is an interesting one. Were you to look inside an SA12 you would find it crammed with pedigree audiophile grade parts.

Peer inside the Redgum and let’s say, the roll call of the parts used is underwhelming. To be frank, they are plebeian grade and not what you would expect from a brand whose profile is that of an Audiophile manufacturer.

Stepping back, we have the Counterpoint amplifiers chock full of premium parts but with an inherent unreliability issue. And then we have the Redgum amplifier with its complement of a handful of rather ordinary parts, but rock-solid reliability.

Both brands wring a commendable level of Audiophile sound from their models, but whereas the Counterpoint was very expensive, the Redgum Black series amplifiers are priced to please most buyers.

The other issue that surfaced with the Redgum concerned its pair of pesky volume controls. The last bit of audio gear I had that sported two volume controls was a Trevor Lees, Positive Vibes valve preamp. That was thirty-two years ago.

The frustration and anxiety created by trying to adjust independent volume pots is still a pain in the derriere three decades later.

Moreover, the Redgum’s dual volume controls behaved erratically. The amp had to be reset by switching it off and then repowered.

As for the styling, it’ll divide enthusiasts. The black, minimalist main chassis bedecked with round operating dials is retro-like. However, the bottom half which houses the massive heatsinks is post-modern.

I love the design. It is fresh and innovative.

As for the heatsinks, they remind me of the amplifiers made by UK brand Alchemist and one, in particular, I owned called “The Kraken’’.

So we have come to call the Redgum, “the Junior Bunyip” because it does look like it wants to lurk by a Billabong.

The RGi35ENR is built in China at Regum’s own factory, an arrangement that gives the brand total control over quality control. The PCB boards come from Taiwan and are shipped to Australia so Robinson can install and program the Programmable Interface Controller that operates the input selector.

Robinson also installs the MOSFETs that he buys from Exacon in the UK. Some of the boards are retained here in Australia where they are used to build Redgum’s Amplifolia series, a range hand built by Robinson and co-owner Lindy Gerber.

But Robinson will tell you the three Black series models use PCB boards identical to three of Redgum’s models built in Australia.

The RGi35ENR arrived packed in a heavy-duty export carton. Inside was a comprehensive and very informative owner’s manual.

As for the amp, it is a model rated at 65 watts per channel into 8 ohms, 80 watts per channel into 4 ohms and 95 watts per channel into 2 ohms with the power measured driving 20-20khz.

Harmonic distortion is very low at 0.009 percent as is intermodulation distortion at 0.005 percent. Signal to noise ratio is 100dB while input impedance measures 10k (matches 600 ohms-50k).

The RGi35ENR has a peak current of 120 amps and a frequency response of 0.8hz-80kHz (-3dB points).

Connections comprise five, colour coded line inputs. The RGi35ENR weighs 11.8kg and measures in at 410mm wide, 330mm deep and 150mm high.

The system used to audition the Redgum comprised an Audio Research Reference CD7MKII CD player, Linn LP12/Ittok/Karma cartridge, Musical Surroundings Phonomena 11+ phono stage, Dynaudio C220 floor standing speakers and Inakustik speaker and interconnect cables.

From the get-go, the Redgum produced some of the musically engaging qualities I heard at the recent Melbourne International Hi-Fi Show where Redgum was driving Legend Acoustics speakers.

What impressed me there and now at home was the amount of dynamic attack the Redgum delivered with what seemed like arrogant ease.

The Fink track Biscuits from the live album 'Wheels Beneath My Feet' requires an amp with bundles of macro and micro dynamic ability.

The RGi35ENR provided oodles of macro dynamics but wasn’t as impressive with micro detail, with voices hidden behind other voices singing the same notes partially obscured.

You had to work hard to hear these lower intensity vocals hiding behind those in the foreground. But realistically few $2000 amps deliver audiophile grade macro and micro dynamics.

The Fink track was still thoroughly enjoyable thanks to the Redgum amp’s informative, fast and taut bass matched to fairly detailed and extended treble.

Tonal balance was on the warm side of neutral, but it was never over ripe or overly rich harmonically. In fact, it was just right to match the neutrality of the C220 speakers and the Inakustik cables.

Readers who follow my reviews know I never complete a review session without Morrison’s 'Astral Weeks' featuring somewhere in my listening session. The album has one track that more than any other on the album, tells me what I want to know about an audio system or component.

It is called Ballerina, and it is a long, majestic track with insistent bass, dense compliment of instruments and a mesmerising pulse that if reproduced the way it deserves, opens up avenues of musical beauty.

Through the RGi35ENR, Ballerina was an immersive experience thanks to the amp’s abundant drive and wonderful sense of timing. Qualities that had my feet tapping and my fingers clicking in unison with the music.

However, I also heard a lack of fine detail and a dearth of transparency, particularly through the core of the music - its midrange. Background instruments were reproduced but not in stark relief to those more prominent in the foreground.

The soundstage was huge with plenty of left to right spread and height. Imaging was also tight and precise, but the leading edges of instruments and performers were more rounded than sharply outlined.

Speaking of imagery, few songwriters can match the late Jesse Winchester’s ability to paint a vocal and musical scene particularly when he was writing a tune about the American south, where he came from.

Bowling Green is a track from his early album, 'Nothing But A Breeze', and about a moment in summer in Kentucky. It requires a system with the ability to conjure finesse and musical grace.

With my normal reference electronics comprising the five times more expensive Elektra pre and power amplifier, I feel I can walk into the Kentucky bluegrass and feel the warm sun on my back.

The amount of detail etched by the Elektra gear presented with a Class A level of transparency makes me a participant in Winchester’s musical painting.

Via the vastly cheaper Redgum, I was an observer looking out a closed window into the Kentucky countryside. However, bear in mind, the usual $2000 integrated won’t even get you out of your listening chair let alone afford you a window perch.

Even so, throughout all the tracks I played using the Redgum RGi35ENR one quality stood out: musicality.

Despite the lack of transparency and a dearth of subliminal detail, the Redgum was thoroughly enjoyable and so engaging each track was a joy to hear rather than one to endure.

A generic quality I heard as the Redgum amps strutted their stuff with the Legend speakers at the Melbourne International HiFi Show. And really at the end of the day, I’d happily give up most of the audiophile audio “must have’’ performance parameters as long as the gear was compellingly musical.

So we arrive at an amplifier and a conclusion that suggests the Redgum RGi35ENR is an integrated amplifier that pleases the heart.

For more information visit Redgum Audio.


Peter Familari's avatar

Peter Familari

One of the veterans of the Australian HiFi industry, Peter was formerly the Audio-Video Editor of the Herald Sun for over two decades. One of the most-respected audio journalists in Australia, Peter brings his unparalleled experience and a unique story-telling ability to StereoNET.

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Posted in: Hi-Fi
Tags: redgum audio