[Review] Soundsea Bora 20 digital amp & DAC

Soundsea Bora 20

Amplifier and DAC

Product name: Bora 20
Manufacturer: Soundsea - Slovenija
Cost: €1030 euros (Currency conversion)
(YMMV)

Reviewer: Mike Cox - TNT UK
Reviewed: August, 2014

Introduction

Recently the audio world has been evolving and a new type of product has appeared, the digital amplifier. Products such as the Devialet 120 typify this new generation. The inputs are digital with any analogue input going through analogue to digital conversion first. The Devialet product family have received rave reviews from the regular HiFi press, as they should when you consider the price.

Soundsea have entered the audio arena with an all digital amplifier called the Bora 20. The Bora name comes from a easterly wind that blows in the province of Trieste. The Bora is strongest in the winter, reaching speeds of 100mph (152kph) or more. The 20 refers to the continuous power output of the amplifier into an 8 ohm load.

The Bora 20 Solution

The Bora 20 from Soundsea performs similar digital magic at a more affordable, if still expensive price point. The Bora has two digital inputs, Bluetooth and TOSLINK optical, there are no analogue inputs. Whilst I mentioned the Devialet product family being conceptually similar the design implementation is different. The Devialet uses a convential DAC chip with a current to voltage output stage followed by a high quality, low distortion, voltage amplifier. In parallel there is a class D current amplifier with an error correction circuit to ensure the class D stage matches the voltage stage output. In my mind there are similarities to the 1970s Quad current dumping design.

The Bora 20 takes the digital input and passes it to a digital signal processor (DSP). The DSP then converts the digital data stream into a pulse width data stream to directly drive the class D output stage. Soundsea describe the design as having a dual mono architecture as it has 2 power supplies, 2 digital amplifiers and 2 output filters. The picture above clearly shows the 2 power supplies, the grey modules with the Soundsea labels. The DSP and digital amplifiers are hidden underneath the circuit board.

All the digital technology and switched mode power supplies mean the amplifier is very efficient. Soundsea quote 85% for the efficiency, typical for most switched mode power supply equiped, class D amplifiers. In my setup and played hard, the amplifier never got more than slightly warm, so it must be efficient.

The construction is also different, the bottom and top are CNC machined aluminium plates. The plates are separated by carbon fibre moulding for the front and sides plus a small aluminium insert at the front where the indicator LED shows through. The back panel is another beautifully machined piece of aluminium. The build standard is very high, so the Bora 20 looks as good as anything I have ever used or owned. If desired, you can have the construction customised with your own engraving on the top and special carbon fibre weave for the spacers. The amplifier comes beautifully packed in a wooden box engraved with the name and foam lined to protect the amplifier. The specification for the Bora 20 is as follows:-

Power per channel into 8ohm - 20Watt continuous
Dynamic power - 30Watt/ch
Distortion - 0.06% (20-20kHz)
Channel Separation - 120dB @ 10kHz
Power supply input 110-240VAC 50-60Hz

Setup

The setup could not be simpler, connect the speakers and if you have a Bluetooth source, connect to the "Bora 20" device and play your music. The amplifier automatically selects the input with Bluetooth taking preference to TOSLINK. As a Bluetooth source I used the iPad with the Spotify application and this configuration work flawlessly. If you want to use the TOSLINK input disconnect the Bluetooth source and fire up your TOSLINK source. I used my MacBook Pro runing both iTunes/Pure Music or JRiver Media Centre.

You can tell which input is selected by the colour of the LED on the front; blue for Bluetooth and green for TOSLINK. Another unusual feature (or lack of) is the amplifier has no volume control. You use the volume control on your digital source. When using Bluetooth and Spotify from the iPad this is very convenient as the volume is adjusted using up/down buttons on the side of the iPad. When using the MacBook Pro this requires you to use a slider control in the application. I find the slider control more fiddly to use, and this becomes even more of a fiddle when using the JRemote application on the iPad as a remote control for JRiver. The same irritation is present when using iTunes/Pure Music with the associated application on the iPad. If you are using a source without a volume control it is possible to adjust the volume of the Bora 20 using an application running on an Android device like a smartphone or tablet. It is also possible to configure the Bora 20 to match speakers with different impedances, again you will need the Android application. There is a comprehensive set of user instructions to guide you through these settings. As I did not have an Android device I left the settings as they were. My speakers are an easy load from a single full range driver.

Once you have used the system for a few hours these small irritations with the volume setting fade. I settled into using the Bora 20 using my Eryk S Concept Superioro speakers as featured in a recent review. I also experimented with my Magneplanar SMGa speakers and was amazed to find the Bora 20 worked very well. Normally I use a 500W/ch Emotiva amplifier for the Magneplanars as they like lots of volts and the low output impedance. I completed the review using the Superioro speakers as they represent a closer match to the load and efficiency of typical speakers.

How does it sound

Using the Bluetooth input fed data from Spotify via the iPad, the sound was as good as any other DAC/amplifier combination. There is plenty of detail, the Bora 20 recreating the ambience of the recording environment very well. The rhythm and timing are excellent, giving a most enjoyable experience. The combination of the Bora 20 playing music from Spotify streamed via a tablet is a very tidy setup. The Bora 20 can be sited on a bookshelf with little ventilation as it runs so cool. The only input cable is for power and the output is the speaker cables, compared to my regular setup with pre-amp, power amp, DAC and all the associated cabling the Bora 20 i very neat. In these times, where space is a premium, an audio setup that takes up the minimum space is a real bonus.

Moving on to the optical input, I fed it a range of material from regular CD rips at 16bit 44khz to 24bit 192khz downloads. The formats were FLAC, WAV, Apple lossless and even some MP3s. Through my speakers, the sound was dynamic and exciting with a very good ambience. The level of detail was excellent, as good as my regular all valve setup. Where the Bora 20 loses out is with tone, the sound being very clean and rather dry compared to the valves. Recently, I have been given access to some 24bit 192khz music files from Katzenberger Music. This is a label that specialises in recordings without post processing or digital manipulation. The music is simply recorded using the best equipment and well placed microphones. As Katzenberger put it, "This means that we focus on authentic reproduction of the original sound, both technically and musically, avoiding the use of reverb, filters, compression and other artificial processing in order to achieve honest, natural sound quality". One particular recording attracted my attention, the Suite Espagnole No. 5, Asturias played on the harp by Anne-Sophie Bertrand. This recording played through the Bora 20 is simply marvellous, lots of detail, with a very good tone from the harp. You could argue that the Bora 20 is a better representation of the truth, where as my valve setup is like looking through rose coloured glasses. Which you prefer will depend on the rest of the system, the lean quality goes well with the Magneplanar SMGa while the valves are a better match for the Superioro speakers.

Conclusions

If you only have a digital music library stored on a computer then I think the Bora 20 is an excellent amplifier. The Bora 20 seems to be able drive a range of speakers, consistently producing a highly entertaining, musical sound. As I prefer the the Apple products, I was very happy with the Bora 20. Using either PureMusic with iTunes or JRiver on the MacBook Pro, with the corresponding remote application on an iPad the setup provides a very user friendly interface.

The Bora 20 handles all the current range of music formats up to 24bit 192khz and clearly demonstrates the benefits of the higher resolutions. For me the Bora 20 is missing any form of analogue input, I have a collection of vinyl that I will not live without. I need an input that will take the output from my Whest phono stage. I was unable to try the Bora 20 with a MS Windows PC as I do not own one with a suitable TOSLINK output but see no reason why this would not work just as well.

The Bora 20 may seem expensive but when you remove the need for a separate DAC and all the associated cables the value improves significantly. I love the simplicity the Bora 20 brings to audio replay, the reduction in box count and jungle of cables is sure to win domestic approval.