FAQ

In the early nineties, the designer of REDGUM amplifiers, Ian Robinson, set out to make an amplifier that was worth selling on two counts – one that, above all, made you feel that you were “there”, but also one that was reliable, indestructible, and reasonably priced. With thirty years experience in the Hi-Fi industry in both retail and as Authorized Service Agent for many major brands, Ian had a very clear picture of what worked with a product, and what did not. When this was combined with his love of a truly Australian wood, REDGUM amplifiers was the result. An on/off key switch completed this distinctively individual product. Many other features are incorporated into the electronics, with the resultant sound of having “live musicians at the end of the room” (personal communication, Rich Weiner, reviewer, Bound For Sound).

Why the name REDGUM?

If any one wood conjures up the essence of Australia, it is Red Gum. The grandeur, complexity and variety of colour and texture of this wood is a reflection of the quality of the sound from this amplifier – alive and durable. Each REDGUM front panel is made from one solid piece of unfilled natural timber, selected and finished to maximize the character of its grain. Red Gum has played a role from the earliest times of our country’s history – it is a part of the national psyche. This wood creates its own atmosphere and emotions. A REDGUM does the same.

Where are REDGUM Audio products made?

These days, it takes people by surprise that a full range of Hi-Fi products, our Amplifolia range, is still designed and made by one company here in Australia. But then to shake things up to celebrate our 21st Birthday, the Black Series of Integrateds was added. These took their names and DNA as clones of those original wood-fronted models, but to provide tighter production costs to meet customer expectations were made in China. Regardless, component quality remains at the level found in REDGUM’s Australian-made product and thus the sonic signature is, as always … “Stunning!

 

recalibrated the full range

All REDGUM Audio Products are designed in Australia by the only Australian manufacturer of a full Hi-Fi Stereo range.

 

REDGUM’s Amplifolia range really is made in the suburbs of Melbourne!

Are REDGUM products compatible with other brands of equipment?

There are no compatibility problems when using REDGUM products with those of other manufacturers, other than those normally requiring consideration, such as power requirements, impedances, etc., (Indeed, since the launch of the first amplifier in 1993, that should have been enough time to check things out!)

One point worth mentioning however, is that REDGUM amplifiers are power rated very conservatively, and this should be born in mind when choosing appropriate speakers. For example, our 200 watt Articulata amplifier peaks with Transients of 320 Watts RMS!! On the other hand, they are only transient peaks.

Are REDGUM products available with front panels other than red gum wood ?

Although we are passionate about our distinctive Red Gum wood fascia panels as a signature of the Amplifolia range, we realize that in some environments they may not harmonize aesthetically. This issue of colour was one of the reasons for the introduction of the Black Series.

We trust you enjoy the choice between these two ranges, with the link between them being our Signature Series SignWave heat sink.

Can I order a REDGUM amplifier without a key switch or labels?

“Shocked” as we are that you would want a REDGUM amplifier without its distinctive key trademark, the answer is …a qualified “yes!”. For manually controlled units only, we can supply our amplifiers with a toggle power switch. This is a request that we receive from time to time, so just mention when ordering. On the other hand, for remote controlled units, the key must remain as it is an integral part of the remote control function.

If you love the look of the Red Gum wood as much as we do, we certainly understand why you might prefer to dispense with the knobs’ label. Just mention when ordering.

Do all REDGUM products now have remote control?

In 2007, REDGUM released the world’s first Dual Mono remote control for its amplifiers. It remains a unique feature and is standard on all amplifiers, Amplifolia range and Black Series. (However, Audio Purists can relax as they can request any Amplifolia Stereo amplifier to be built with manual volume controls if wished.)

Since the first bold step, REDGUM CD Players also became remote controlled as did the RGH900p Home Theatre Preamp/Processor.

Are REDGUM Audio products suitable for use in other countries?

All REDGUM amplifiers now provide Automatic 110/240 Voltage Selection upon power up so they can be plugged into mains supply in any country and can self-adjust.

REDGUM products have also passed the CE Mark and the C-Tick test, the Australian standard for RF emission – a plus for export markets. REDGUM Audio is delighted to be able to assure its customers that REDGUM amplifiers pass the C-Tick test, not just individually, but when combined with the REDGUM DAC/CD Player. (As REDGUM speakers are passive electrically, they do not require testing.) The C-Tick standard is based on other international standards and is an important factor when marketing a product for export.

The need for such tests is now commonly assumed because of the world’s reliance on mobile communications and devices using microprocessors. A serious consequence of this is the interference to radio communications, an ever-increasing problem as the use of electrical and electronic products is so widespread. This interference is caused by the lack of compatibility between products and the electromagnetic environment. The enforcement of radio frequency (RF) emission standards is intended to reduce unintended emission levels. Just as the European Union has set its own standard with the CE Mark, so Australia required all electronic and electrical products sold from 1 Jan 1999 to bear the C-Tick Mark. By law, stringent tests are carried out only by accredited testing houses. REDGUM passed these with flying colours!

Why were these CD players unique from the outset?

In 1997, REDGUM’s RGCD5 DAC/CD Player was presented as the world’s first user-serviceable CD Player. Versatile as a CD player or DAC, it was designed and made in Australia based around Burr Brown components. REDGUM Audio had produced the world’s first Digital-Analogue Converter that had the versatility of enhancing an existing system or being upgraded to a CD Player – a unique product in Hi-Fi. In addition to this, in today’s terms, those DACs

And the logic for a need to be upgraded? When the most usual repair problem arose (laser assembly malfunction), customers could immediately remedy it themselves without needing any expertise or labour costs. The most frequent point of failure in a hi-fi system in those days was the CD player. The most frequent point of failure in the CD was the laser assembly. Even back then, we were all becoming too familiar with the solution that “it is cheaper to get a new one”! So it became a case of if the customer was satisfied with the sound quality of a cheap replacement CD player when the laser “died”, then honour was satisfied. But Hi-Fi enthusiasts demand much more from their hand-picked product, usually chosen at great expense. They rightly expect a longer life for such a price.

REDGUM concept was a solution to short-lived CD players – discard only what needed to be discarded, keep what is of value. In a REDGUM DAC/CDP the electronics are valuable. Starting in 1997, REDGUM DACs have been asynchronous as the digital stream is fully reclocked and reshaped in a separate, additional chip. This additional chip also provides the buffer for the storage of the data stream in real time, thus removing the problem of jitter. Also from the start, the Rolls Royce of 20 bit DA chips were used – Burr-Brown Integrated Circuits. Combined with this was the high standard of the DAC design by Jon De Sensi of Music Labs fame.

As to what should be discarded, the logic of REDGUM’s designer was simple. If the customer could simply replace the faulty part when necessary, the sound quality of the system could be maintained using a CD ROM drive in the place of a conventional CD laser assembly. By undoing only a few screws, the customer could immediately “repair” a faulty laser, or upgrade to a preferred drive. No labour costs – just the the continued enjoyment of high quality sonics.

What is the difference between the RGDAC2/RGCD2 and RGDAC5/RGCD5ENR?

The RGDAC5 (and the RGCD5ENR) have the ‘top of the line’ American Burr-Brown’ DACs – the PCM1702 – these were the first sigma-delta DACs designed by Burr-Brown and have long been regarded as the Rolls-Royce of 20bit DACs. The RGDAC5 uses 2 separate DAC units which are combined with, and direct coupled to, 2 x Analog Devices ultra low noise BiMosfet single channel op amps as output stages. This combination is supplied with its digital information via a Cirrus Logic Reclocking and Reshaping chip with its own internal crystal clock (to remove jitter entirely,) and an NPC (Japanese) close tolerance digital filter.

The entire product is direct coupled, silicon to silicon, from the digital stream input to the RCA sockets on the back! – no capacitors (or phase angle changes of any sort throughout). This is made possible by the use of 7 (yes, seven) independent internal power supplies. There is currently no better way of getting clean audio from a digital stream.

As to the RGDAC2 (and the RGCD2), once the PCM1702 DAC was established, Burr Brown saw the possibility of making ‘economy versions’ of this DAC (as the development cost of the Sigma-Delta circuitry was now covered). So they then released a dual channel ‘surface mount’ Sigma-Delta DAC – the PCM1710. This has both channels in the one surface mount chip, and can be supplied with a single operating voltage (5v), thus simplifying the power supply needs. In the RGDAC2, REDGUM uses this PCM1710 supplied with the same Cirrus Logic reclocked digital stream as in the RGCD5ENR (but without the extremely expensive NPC digital filter). The PCM1710 drives into a dual channel version of the Analog Devices BiMosfet chip (as mentioned above), but these stages need to be capacitor coupled from the DAC (as are 99.999% of all CD Players) as there is a ‘bias’ voltage on the output of the PCM1710. The result is that the RGCD2 is better sonically than virtually any mass-produced CD player.

If your early REDGUM CDP needs a remote control

BYO Remote Control accepted by a REDGUM DAC

N.B. The following article has been included for owners of (early) DACs seeking a way to add a remote control facility, and therefore is more of historical interest only beyond the technical details, which remain current. (Remote-controlled REDGUM CD Players became standard in 2007.)

Should the style of REDGUM’s “less than conventional mass-market appeal” CD player stretch your comfort zone a little too far …
… a simple Solution to work around the lack of a remote and readout in the REDGUM CD Player is … B.Y.O. Remote” i.e. create your own quality CD Player by the addition of a REDGUM DAC only!

To achieve this, we suggest connecting any inexpensive DVD player, or your current “under-performing” CD player, (with either being used simply to provide the transport) to the DAC version of a REDGUM CD player. In this way, you can dramatically improve the sound quality of the DVD or CD player up to Hi-Fi levels whilst enjoying the comfort of the “bells and whistles” from the DVD or CD player via its remote. Most basic DVD players have the necessary Digital Out to allow this connection.

You may be reeling from the idea of “matching” a cheap DVD player with a Hi-Fi REDGUM DAC!? This combination is, however, a great match as the quality of the DVD player becomes irrelevant because of what happens to the signal after it leaves your chosen player.

Once in the REDGUM DAC, the digital stream is fully reclocked and reshaped in a separate, additional chip. This additional chip also provides the buffer for the storage of the data stream in real time, thus removing the problem of jitter. Thus, there is a clear delineation of the digital signal from the “brand X” DVD player changing to the digital signal in the REDGUM DAC.

Just as REDGUM uses only the Rolls Royce of ICs from Burr Brown, having such an extra chip is definitely not the norm! In fact, put in today’s terms, REDGUM DACs sold since 1997 have been asynchronous. This design difference way back then makes sense of comments (i.e. shows the contrast) re the transport being not/important. In this way, if the quality of the transport is important (i.e. non-REDGUM, no extra chip), then and only then does having a dedicated CD player makes sense.

Doing the sums on this combination also gives a positive – by using a DAC, what you don’t pay for the CD ROM drive usually covers the cost of an inexpensive DVD player acting as the “replacement transport”. When you move on to your next DVD player, the DAC remains as part of the system providing you with long-term sound quality along with the flexibility to keep up with the latest development in DVD players.

The original concept of the REDGUM CD Player was formed in 1997 and based on a twofold principle. Firstly, it was aimed at the audiophile for whom sound quality had to be outstanding, and at the same time who could live without all the extra “conveniences” that a readout provides ….. especially because of the convenience provided by the second design principle. Namely, as the transport is the most likely section to fail of any CD player, that section in a REDGUM is made to be “instantly replaceable / serviceable”.

This is possible as the drive in a REDGUM is quickly and safely accessible by a basic technician so that when it fails, a replacement drive can be sourced from a computer shop without loss of time and immediately inserted at minimal cost. In this way, the universal weakest link in conventional CD player design disappears as a long-term liability for the REDGUM customer. Within the scope of these terms, the product definitely held its own with customers. CD ROM drives can come and go, but their REDGUM DAC is theirs for life.

At first glance, the ‘ergonomics’ of a CDROM drive do make it just a little more difficult where many and rapid changes are required, such as demonstrating in a retail situation. However, we consistently find that the RGCD models are welcomed by customers who just listen to discs in their entirety (as is generally the case with audiophiles). From its first design concept, it was never intended to be a mainstream product.

Interestingly, the initial RGCD models used ROM drives that offered remote control! However, due to quality control issues totally out of REDGUM’s hands, the brands of drives have varied since 2002, with non offering a remote facility.

Seemingly quirky as the REDGUM CD Player design is, its purpose is re-justified by its ability to act as a DAC with any level of transport quality (from another CD, or DVD player).

The fact that at REDGUM we use a CD ROM drive as our transport indicates our assuredness that after the signal leaves the transport, what happens inside our DAC must, and does, bring the signal up to and hold it in top notch condition. A coherent digital stream is needed if the sound quality is to be optimal, which it is. (No point in being modest here. It IS !!! How many of our customers have left their well-known brands behind after hearing even just the RGCD2!! – see our testimonialpages.)

We know you will agree that there is magic to weave by doing things just a little differently!

REDGUM is delighted to offer you …

“Insight for Sore Ears!”

Tell me something about the speakers.

REDGUM loudspeakers offer style, value, and performance.
Australian-made with real Red Gum wood veneer

Designing speakers was not new territory to the electronics’ designer of REDGUM, Ian Robinson. Drawing on the experience in the ‘70s of designing his successful range of Link speakers was a natural progression to complete the presentation of what has been “the REDGUM sound” since the late 1990s. With the support of the LEAP software (as developed by Thiel and Small), REDGUM was able to develop a range of speakers that kept pace with a rapidly changing audio industry’s requirements. The range extended over time to present the versatility of Stereo or multi-channel use.

A REDGUM system aims to leave nothing but its hallmark of sonic neutrality on the signal. This involves both a fine balance between the active units, plus the electronics being carefully matched to the passive unit, the speakers. Within the speakers themselves, there is another balance to be attained. The speaker box shape, providing the audible and visceral impact, needs to complement the visual impact, which relies on the veneer used. REDGUM believes it has captured the best of both aspects. The musical training and live performance experience of the design team has permitted their ears to tune the system to its finest point, a worthy match of aural to visual beauties.

The Veneer: REDGUM Standmount and Floorstanding Speakers use real red gum wood for the veneer. Regardless of the make of a speaker, sonic consistency within each pair and between all pairs of speakers requires that the speaker box is constructed from MDF board. However, this visually uninteresting material needs to be covered with a veneer for the sake of durability and aesthetics. Only in relatively recent times was the technology first available to create red gum wood veneer, as it is such a difficult wood to reliably work with. To be able to offer our speakers in a wood of such grandeur, is to offer a uniquely Australian product.

The Speaker Shape: All of REDGUM’s Standmount and Floorstanding Speakers are able to create such a realistic performance that the listener can experience the feeling of “being there”. In part, this is due to the design of the speaker box. For example, the internal structure for the Lucens Floorstanding boxes is separated into two (between the level of the drivers), with the dividing panel sloping downwards. In effect, the lower section acts as a subwoofer. This speaker has been successfully tested to the limits of an Audiophile test disc – when the test tracks ran out at 20 Hertz, the speaker was happily performing and still ready for lower subsonic frequencies.

Transforming these same speakers into a practical Home Theatre combination was simple – use the same internal volume, and lay them on their sides! Thus, the fully-shielded REDGUM Centre speaker and Subwoofer were created to stack together, thus forming a space-saving pedestal base for a large screen TV of the era.

Why does REDGUM make those powerful (300+W) Monoblocks?

Why would you ever want 300 Watts a channel!!!

Most people would say … “Nobody ever listens to music that loud!” The reality of it is that for accurate reproduction of sound, you do need 300 Watts per channel – for not only what you hear under normal circumstances, but for what you need in reserve. It’s all to do with the way music is made up! A few background facts will make this clearer.

the rustle of leaves produces about 45dB
a noisy office is about 65dB
‘average’ level of listening to music is 90dB
modern CDs have a dynamic range of 90dB or more.
modern dynamic speakers use 90dB/Watt whereas modern planar-type speakers may be as low as 82dB/Watt (that is, 1 Watt of tone signal in = 82dB of tone heard)

But it is the ramifications of one other fact that is often underestimated in sales hype. Fact – to make something sound twice as loud you need a level of 10dB more – this requires 10 times the power!!!

An example :- if you had a piece of music where a drummer was quietly using brushes on his kettle drum, and then proceeded to lay on a couple of very serious ‘rim shots’, these rim sounds are likely to be 50dB louder than the sound of the brushes. A not uncommon situation. To decide whether an amplifier is responsive “enough” to accurately reproduce the transient of the rim shot, what needs to be known is how much power is required.

With the lower efficiency of planar speakers at average listening levels (= 82dB/Watt), a realistic sound pressure level for the brushes might be 62dB. Using the inverse of the relationship of 10dB more needs 10 times more power, the maths are as follows :- if 82dB per 1watt, then 72dB requires only 1/10 Watt and 62dB per 1/100 Watt. In other words, any amplifier (even Class ‘a’ types) would perform well enough in such a quiet passage. And this is why so many people can remain satisfied with their amplifier’s performance of undemanding music.

However, when you suddenly hear the rim shots at 112dB (ie. +50dB on 62dB), you are much better able to assess the true ability of your amplifier. Some more maths! Starting with our base figure of 82dB per 1 watt, the progression is 92dB per 10W, 102dB per 100W and 112dB per 1000 Watts. To be honest, even a 350W REDGUM fails to totally reproduce the entire wave form, but our amp certainly gets a hell of a lot closer than most! But your body sure will jump at the crack of sound of the drum. It won’t just sound like a finger tapping on a paper cup, with your brain filling in the missing information based on experience. If you demand realism, then you need the REDGUM Magnificata, which grew out of the earlier RGM300ENR!

Why then, are most amplifiers unable to produce fast and accurate enough transients to recreate the original sound? Most exotic amplifiers have a very rigid power supply voltage, and this is done in an attempt to maintain stability. Because REDGUM amplifiers are inherently stable under rapidly changing power supply voltages, all our amplifiers have a power supply which is incredibly flexible, giving almost unbelievable transients.

By using REDGUM’s own UltraFlex Power Supply, this >350/>550/>900Watt amplifier (into 8Ω/4Ω/2Ω) gives Short Term RMS power outputs of over 500/1000/2000W RMS per channel to cover the sorts of transients described in the example above.

Why do our Subwoofer Plate amplifiers incorporate a 'HARDLIFE Board'?

Initially offered as an option, the HardLife board has long been a standard with all our Subwoofer amplifiers. Some subwoofer drivers have impedances as low as 1.8 Ohms (Peerless, for example) and they are also inefficient, requiring lots of current to produce the required result. Our HardLife board is particularly effective when used with those sorts of drivers.

Why do REDGUM amplifiers have 'Dual Mono' volume controls models?

Since the very first design, all REDGUM amplifiers have had Dual Mono volume controls, a not always popular decision but based on our desire for excellence. In practice, that means being able to adjust the two volume levels separately is actually creating the Balance without using a single volume control! And on the technical side, the use of two volume controls is a method of minimizing both the number of contact points within the volume controls and the resultant distortion of the sound. Hence we understood that our models with Dual Mono volume controls were slightly technically superior to their equivalent single control versions, which were offered only for a few years later on.

And then with our release of the world’s first Dual Mono remote control in 2007, it became irrelevant how many volume controls there were on the amplifier. The Dual Mono Purist has complete control of the acoustic space by the balance created between the left and right channel volume levels. (And what imaging!) And for those other moments, the Couch Potato in all of us still has Volume Up/Down (as the two channels just increase or decrease together).

And if you get lost between either of those modes, there is always that button that saves the moment. One press and the 2 separate volume controls/pots are physically matched to within 0.1dB, and at best 0.01dB! All done automatically within less than 2 seconds by smoothly repositioning, checking and recalibrating the controls up to 200 times! Not that you’d notice!

Where can I purchase REDGUM Audio products?

Firstly, if you would like information about the REDGUM product range, please select  ‘PRODUCTS’ from the menu bar and then select from our Australian-made, wood-fronted Amplifolia range, or the Black Series (Integrated amplifiers only).

Then to purchase, countries that are not covered by a Distribution network can do so directly via our website. So please check for a local distributor on the menu, under REDGUM INFO. Or feel free to contact us at sales@redgumaudio.com

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