Rega IO review: a small stereo amplifier that packs a big punch

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Today we reviewed the Rega IO mini amplifier, a user-friendly compact stereo model with a minimalist design. Released in March 2020, it has already received a five star rating from What Hi-Fi? Magazine and the Best Buy label from The Ear and AVforums.

With its compact size, the Rega IO amplifier can be easily placed in a small hi-fi cabinet or even on a shelf.

The Rega IO delivers 2 x 30 watts into 8 ohms and has three RCA inputs, including a phono MM input. Its large toroidal transformer promises a hefty power reserve to efficiently drive a pair of compact speakers or even a “small” pair of floorstanding speakers.

The Rega IO is also equipped with a mini-jack headphone output compatible with IEMs and hi-fi headphones with an impedance between 32 and 300 ohms on its front panel. Can this mini Rega IO amplifier that is sold for €499 rival larger contenders?

Rega IO: the brand

Founded in 1973, the British brand Rega stood out right from the very beginning due to the original design of its turntables and the excellent performance of its phono cartridges. It wasn’t until the early 1990s that the brand released its first integrated stereo amplifiers, including the first Rega Brio in 1991.

Released in 1991, the Rega Brio stereo amplifier delivers 2 x 50 watts into 8 ohms. Esthetically, the similarity to the Rega IO is striking.

The British brand’s amplifiers benefit from Rega’s expertise regarding warm analog sound, know-how acquired through decades of developing turntables. Also released in the 1990s, the Rega Elex and Rega Elicit amplifiers offered a rich, full sound with solid lows, and have delighted both previous and current generations of audiophiles.

The Rega IO amplifier that we reviewed today is the first model in Rega’s stereo amplifier range, which also includes the following references:

Rega IO: packaging & accessories

The Rega amplifier comes with a power cable, a remote control and two batteries as well as a user manual. Everything is held in place with foam wedges inside a reasonably sized box bearing the inscription: “Rega – Made in England”.

Rega IO: presentation

The Rega IO’s front panel perfectly illustrates the simplicity and minimalism of this stereo amplifier.

Compact and minimalist design

The Rega IO stereo amplifier is a bit like your dad’s amp: straightforward and easy to install and use. The front panel is very simple, and one could even call it spartan. It features:

  • An ON/OFF button and a headphone output (3.5mm mini-jack) underneath the window of the infrared receiver for the remote control on the left
  • A source selection button with LEDs for the selected source and a mute LED in the middle
  • A volume potentiometer on the right

There is no LCD control screen, power VU meter or scale for the volume level on this amplifier!

The Rega IO amplifier is only 18cm wide, 6.8cm high and 29cm deep.

The only embellishments that the manufacturer has allowed itself are the Rega logo and the numbers designating the selected source, which appear in white on a black background when the Rega IO amplifier is turned off, and in red when it is turned on. It’s both stylish and understated.

With its compact size, the Rega IO mini stereo amplifier will have no trouble finding a place in a bedroom or office, not to mention a living room.

Connectors

In contrast to the ultra-connected WiFi/Bluetooth amplifiers that are currently very popular, the Rega IO has a simple, pared-down set of connectors including: 

  • Two RCA line inputs
  • A grounded RCA phono input with RIAA preamplification
  • A mini-jack headphone output
Three RCA stereo outputs including a phono input for turntables and screw terminals: the Rega IO’s rear panel provides the essential connectors for enjoying one to three analog sources.

The two RCA stereo inputs can be used to connect different hi-fi sources, such as a CD player, a network audio player or a DAC. The phono input can be connected to any turntable mounted with a moving magnet cartridge.

Lastly, the Rega IO amplifier’s headphone output can power hi-fi headphones or IEMs with an impedance under 300 ohms. The signal is received directly from the power amplification stage and then modified by carefully selected relays to preserve its integrity.

Unlike the majority of stereo amplifiers that feature a 6.35mm jack headphone output, the Rega IO’s output is a 3.5mm mini-format, which is suitable for many current headphones.

Design

The Rega IO stereo amplifier uses the same type of power amplifier and phono stage as the Rega Brio amplifier. More compact and more affordable, the Rega IO is equipped with a class A/B amplification circuit, like the other amps in the British manufacturer’s catalog. Note that this type of amplifier generates heat when in use. It is therefore important to let it “breathe” and it shouldn’t be kept in an unventilated cabinet.

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The Rega IO means business with its large toroidal transformer and carefully selected components.

Although it is the entry-level model in Rega’s amplifier range, this mini amplifier isn’t second-rate. The manufacturer has carefully selected the components, which are housed in a robust metal chassis. Under the Rega IO’s hood are Sanken output transistors, an Alps volume potentiometer and a linear power supply that enables an output of 30 watts per channel into 8 ohms with a generous power reserve. This large power supply and very sturdy chassis account for a large part of this amplifier’s 2.9kg.

Remote control

The Rega IO amplifier comes with an infrared remote control that lets you select the source and adjust the volume. You can use the other buttons to control one of Rega’s CD players.

On the remote control supplied with the Rega IO, the keys that work with the amplifier are those in the white frame.

The remote control, which is compact and pleasant to hold, does its job perfectly. However, it doesn’t allow you to adjust the volume ultra precisely. Pressing the plus or minus key increases or decreases the volume rather significantly. The volume knob on the amp allows for a more precise adjustment. The latter is an ALPS potentiometer without notches that can be adjusted from 7 o’clock (minimum) to 5 o’clock (maximum).

Key specs

Output power

  • 2 x 30 watts RMS with a nominal charge of 8 Ω
  • Line input frequency range: 12Hz (-1 dB) to 43kHz (-3 dB)
  • Phono input frequency range: 15Hz to 40kHz (-3 dB) / 27Hz to 25.5kHz (-1 dB)
  • RIAA accuracy (100Hz to 10kHz): ±0.4 dB (typically better than ±0.3 dB)

Connectors

  • 1 Phono MM input (RCA stereo) + earth
  • 2 line inputs (RCA stereo)
  • 1 headphone output on the front panel (3.5mm mini-jack)
  • 2 pairs of screw terminals compatible with banana plugs

Headphone output

  • Without charge: 8V
  • Into 32 Ω: 1.6V
  • Into 54 Ω: 2.4V
  • Into 300 Ω: 5.7V

Accessories

  • Remote control
  • Batteries: 2 x alcaline AAA
  • Power cable

General

  • Dimensions (W x D x H): 180 x 290 x 68
  • Weight: 2.9kg

Rega IO: listening conditions

The Rega IO amplifier looks tiny next to the Elipson Prestige Facet 8B compact speakers, which are each equipped with a 6½” midbass driver.

For our review, we connected the Rega IO to a pair of Elipson Prestige Facet 8B compact speakers using NorStone Silver 150 speaker wire. We used the Pioneer UDP-LX500 player as a CD player and a network audio player to stream Hi-Res music from the Qobuz app and Hi-Res files stored on a smartphone.

The Rega IO’s speaker terminals accommodate up to 2.5mm gauge speaker wire and are compatible with banana plugs.

To test the Rega IO mini amplifier’s headphone output, we used the second generation Sennheiser Momentum Wireless headphones (28 ohms/113 dB) as well as the Sennheiser HD540 Reference hi-fi headphones (600 ohms/94 dB).

We tested the Rega IO stereo amplifier’s headphone output with two Sennheiser headphones: an open-back model and a closed-back model.

Rega IO: listening impressions

We started our listening session with the Birdman (Alejandro González Iñárritu) soundtrack on CD. Composed and interpreted by Mexican percussionist Antonio Sanchez, the first 16 tracks of this soundtrack were recorded close to the artist. It really felt like he was only a few centimeters away in front of us.

The presence and impact provided by the Rega IO in the lows meant that we were immediately immersed in the soundscape when the bass and tom drums resonated. The amplifier had no trouble moving the Elipson speakers’ drivers, which delivered exceptionally intense lows. Even at moderate volume, this frequency range had substance. We could sense that the amplifier had a lot of power on tap despite only being rated at 30 watts per channel.

On the second track, titled “Dirty Walk”, the cymbals were well reproduced with tom drums hits to underline the rhythm. The high frequencies could have been more precise and the midrange a little more nuanced, but overall the sound was balanced and coherent. With this mini amplifier, we listened to track after track to enjoy the intricate work of the Mexican percussionist. The Rega IO managed to keep pace with an excellent sense of rhythm and fluency down to the lowest octaves.

The Rega IO was very comfortable powering the Elipson Prestige Facet 8B speakers.

We changed genres completely with a CD of Norah Jones’ Feels Like Home. Once again, the Rega IO immediately set the tone in the lows. The bass that opened the first track (“Sunrise”) was reproduced with depth and intensity. The artist’s voice was smooth and well articulated, although it would have been nice if it was a little more velvety and nuanced. It was round, soft and warm, like a big woolly jumper in the middle of winter: not the epitome of refinement, but incredibly comfy!

With high resolution tracks from Qobuz, the sound was clearer and more detailed, without losing what makes this amplifier so appealing: rich and deep lows. When listening to The Girl From Ipanema (Stan Getz/Joao Gilberto – 24-bit/192kHz), the double bass score revealed all its depth and intensity, which helped to emphasize the saxophone, Milton Banana’s delicate drumming and the bewitching voices of Joao and Astrud Gilberto.

When using the headphone output, we enjoyed the same characteristics with well-structured, dense and deep lows, especially with the Sennheiser Momentum headphones’ somewhat bass-heavy signature. The soundstage was a little narrow, but the various elements remained distinct. The headphone amplifier section struggled a little with our high impedance (600 ohms) open-back headphones. The lows lacked substance and the mids weren’t as well rendered as they were with the Momentum pair. It is best to stick to the manufacturer’s recommendation of a maximum of 300 ohms.

Rega IO: compared to…

Marantz PM-6007

The Marantz PM-6007 impressed us with its ability to structure the soundstage with both space and precision, but also with its impact and energy. The Rega IO is equally energetic and comes out on top regarding the lows, which are more intense and deep, though not quite as lively. The Marantz model is better in terms of clarity and fluidity. Its second pair of speaker terminals and its digital outputs powered by the excellent AK4490 DAC are also a big plus.

Marantz MCR612

For an extra 200 euros, the Marantz M-CR612 features a CD player, an FM/DAB+ tuner, a 24/192 and DSD compatible USB audio port as well as Bluetooth, Internet and network connectivity for wireless streaming. Very much in tune with the (almost) all-digital age, the Marantz amp also provides solid amplification and can power two pairs of speakers, offering a balanced sound with plenty of energy.

Although the Rega amplifier is more austere in its presentation and fonctionnalites, it has other advantages to offer, starting with a large power reserve despite an output of only 2 x 30 watts on paper. Moreover, its rich and generous lows will surely appeal to those who enjoy warm sound signatures. The phono stage borrowed from the Rega Brio is also an advantage during the vinyl renaissance. This makes the Rega IO the perfect partner for the Rega Planar 1 turntable, for example.

Rega Brio

A little more powerful and equipped with a total of five analog inputs (including the phono input), the rega Brio is just as pleasant to listen to as its descendant. The Brio offers slightly more powerful lows and is capable of powering any type of speakers. It also provides a more detailed and well structured sound. With the Rega Brio, music has more room to breathe, the timbres are accurate, and available power is expertly controlled.

Rega IO: conclusion

Without a doubt, this mini amplifier’s biggest strength is that it manages to envelope the listener in a very pleasant sonic environment. The width of the soundstage is appreciable. It could be more spacious, but overall, the instruments are nicely delineated and do not bleed into each other.

The lows are a lot deeper and intense than we expected from such a small amplifier. Some might prefer more punch in this frequency range as well as tighter bass. But that would be to the detriment of what, in our opinion, constitutes the charm of this integrated stereo amplifier: its richness and warmth. In short, a British sound.

The Rega IO will work wonders with a pair of compact speakers such as the Elipson Prestige Facet 6Bs and the Focal Aria 905s with their 5” drivers, but also with the B&W 606s and the Elipson Prestige Facet 8Bs, for example, whose 6½” drivers will provide even deeper and more expressive lows.

Ideally, the Rega IO amplifier should be paired with compact speakers with a sensitivity rating of 90 dB or higher, such as the Elipson Prestige Facet 8B, even though its power handling capacity should allow it to efficiently power models with slightly lower sensitivity.

Of course, one may deplore the absence of a DAC, Bluetooth and digital inputs, which are present on competing models in the same price range. However, it is important to bear in mind that, at a time where many electronics are being manufactured remotely, the Rega IO is entirely produced in the UK, almost exclusively by hand.

To make up for these missing elements, you can easily pair the amplifier with a Bluetooth receiver such as the Real Cable iPlug-BTR HD or a compact network audio player like the Audio Pro Link1 or the D-Stream Primo HD, without increasing your budget too much.

Lastly, one should note that unlike digital amplifiers, which give off almost no heat when in use, this class A/B amp heats up quite a bit, which is normal, but this must be taken into account if you wish to install it inside a cabinet.

What we liked

  • The impact and richness of the lows
  • The overall smoothness and balance
  • The ease of use
  • The headphone output

What we would have liked

  • To have been able to adjust the volume more precisely with the remote control
  • An integrated DAC with a few digital inputs


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