Lejonklou Boazu Integrated Amplifier
Lejonklou Boazu Integrated Amplifier
Boazu is an integrated amplifier with ZERO features and stunning musical performance
The decision to make an integrated amplifier was made in the summer of 2015. I had previously felt it necessary to isolate sensitive, low level analogue signals from the strong currents needed to drive loudspeakers. That’s how things are arranged in systems with separate pre- and power amplifiers, such as Sagatun and Tundra. But now I had accumulated some ideas on how these two contradictory requirements could be successfully combined. So work on Boazu (which means ‘reindeer’ in Sami language) began in the fall of 2015.
The most important part of any amplifier – or any system, for that matter – is where the signal starts. This apparently simple but very important principle is called Source First. It dictates that any process taking place early in a chain where a music signal travels has a stronger influence on the quality of the signal than any process taking place later in the chain. When applied to the art of capturing and recording music, it’s easy to understand that the musicians are more important than their instruments, which in turn are more important than the equipment recording the performance. And at home, the recording we play is more important than the HiFi which replays it. But also within the HiFi system, the same Source First principle applies: The source component, such as a turntable or digital streamer, is more important than the amplifier it feeds. And the amplifier is more important than the speakers.
Most people get this wrong and focus their interest on the loudspeaker. Laymen do it because that’s where the sound appears to originate and speakers also vary a lot in how they sound. Engineers do it because loudspeakers don’t measure very well, hence they must be the main obstacle on the road to fidelity. But if our goal is to be moved by the emotional message of the music – to get a thrill – all practical experience shows that the closer to the source, the bigger and more important the differences are.
In Boazu, Source First means that the four analogue inputs are most crucial. In order to optimise them in an effective way, I took a Sagatun stereo preamp and simplified it by replacing the input switches with a circuit that sums every signal present on the four inputs. This means that whatever you play that is connected to Boazu, you will also hear in the loudspeakers. No buttons to press, no display to read. Just play. The main advantage with this solution is that there are no switching circuits to degrade the sound.
After the summing input circuit, an analogue volume control identical to the one in Sagatun handles the signal level. And here’s where the only user functions exist: You can raise, lower and mute the volume, by buttons on the front panel and with the supplied Lejonklou remote control. No other features exist – and for a very specific reason: They all degrade the sound just a little. As a result, the thrill you get from a Boazu is more intense.
Closely tied to the volume control circuit, a power amplifier section almost identical to Tundra adds power enough to drive any loudspeaker with great authority and control. As a large part of the cost when making Tundra is an extremely narrow selection of electronic components, Boazu is cost effectively produced by using component values just outside the ranges used for Tundra. Boazu is also equipped with the same 1.1 kg copper heat sink and dual 100W switch mode power supplies that is used in Tundra. Initially I tried a regular aluminium heat sink, but the musical advantages of copper (clean, solid, perfectly timed bass notes) were just too apparent.
The first Boazu prototype, which was ready in the spring of 2016, didn’t have ZERO features, but four: A phono input, a headphone output and connectors for Pre and Fix Out. I’d spent months tuning it and felt it had become a good integrated amp. But every time I played music with it, I knew in the back of my mind that it would be more fun to use Sagatun and Tundra. At home the listening sessions were not very long, I kept being distracted by other things rather than becoming immersed in the music. I knew this simply would not do. And in an effort to boost performance, I began cleaning up the circuits and removing features. Just as I had expected, each step towards simplicity resulted in a more expressive musical reproduction.
When it was finally ready, Boazu had ZERO features. And at less than half the price, it had actually become a little better than the separates Sagatun and Tundra! To restore the order of the range and to keep owners happy, I released an upgrade called Tarandus for all my pre and power amps. Tarandus is essentially tricks learned from the making of Boazu.
Boazu was released in December 2016.
In March 2017, Boazu was rewarded with a Best Buy rating by Chris Frankland in the British magazine HiFi Critic. Please read the review here!
In October 2017, Reinhard Haberfellner very favourably reviewed Boazu in his blog (in German).