Lejonklou Sagatun Mono Preamp
SAGATUN MONO
PRE AMPLIFIER
How an unusual idea turned into a jawdropping experience
Sagatun Mono is a no compromise version of our stereo pre amplifier Sagatun. It has only one channel, so for a stereo system you need two units. Sagatun Mono started as an idea from the corporate advisor of Lejonklou HiFi, who said “You make power amplifiers in mono, why not pre amplifiers?”
The reason why almost no mono pre amplifiers exist is that there is no power involved. And therefore the benefits of splitting the job in two are not so obvious. But my advisor insisted that I should investigate it, mentioning that some enthusiasts have been using two phono stages, but only one channel on each. And after a period of scepticism, I realised he was right; this idea deserved serious investigation. Already on our discontinued single input preamp Kikkin, there was evidence of an improvement by using two units. When finally removing one channel from a pair of Sagatun’s, the experiment turned into a success. Everything that Sagatun does so well on its own is elevated to a new level when reworked into two Mono pre amplifiers.
The technical reasons why the Mono design is superior is the following:
The signal grounds are completely separated. In any stereo amplifier, the left and right signals travel in separate circuits. The more isolated they are from one another, the better it is. The signal grounds, however, either share the same ground planes or join at certain points. By placing each channel in a separate enclosure, there is complete separation of both signal and signal ground.
The chassis grounds are separated. This is a small advantage. When several channels share the same enclosure, there is always a degree of connection between the signals, through components decoupling to the chassis. Separate enclosures prevent this. But it’s important that both power cords are of the same type and connected to the same power strip, to keep the potentials of both chassis’ identical.
The power supplies can run more silently. This is a surprisingly big advantage. As the circuits of Sagatun Mono require approximately half the power of those in the stereo version, the power supplies can be set to an even more quiet running mode. Just like in the stereo version, there are still two power supplies in each unit.
Individual fine tuning is possible. When the two power supplies feed only one channel, further fine tuning of each unit can be made. This elevates performance slightly.
In order to make two Sagatun Mono’s work smoothly together without having to press buttons on both units, a synch protocol with optical transmission called Control Link was developed. It allows one Sagatun Mono – or one stereo Sagatun – to become Master. Other units are Servants, who follow Master. And while the most common usage of Control Link is between two Sagatun Mono’s playing left and right channels, it also allows you to add as many channels as you want. For instance, an extreme 7.1 Home Theatre system can be built using eight Sagatun Mono’s. Or using four Sagatun Mono’s (for Centre, Left, Right and LF channels) and two stereo Sagatun’s (for the less critical surround channels).
Sagatun Mono uses the same simple and intuitive interface as Sagatun. It communicates with a coloured light the volume and input you have selected. One advantage of this interface is that it can be made extremely silent electrically, so that it doesn’t interfere with the music. In comparison, displays are terribly noisy. Another advantage is that it’s very easy to use and can be seen from a long distance, unlike numbers on a display. To get an idea of how the coloured light works, check out the pictures on this page!
In my opinion Sagatun Mono sets a new standard for the musical performance of analogue preamps. If you are currently using a digital volume control in your HiFi, I particularly urge you to give them a listen. A new world of detail and emotion is awaiting you.
Sagatun Mono 1.3 Tarandus was released in October 2016. It’s a new version with improved musicality and a more refined sound.
Sagatun Mono and Tundra Mono were reviewed by Alan Sircom in the UK magazine HiFi+ in the 2017 July issue. Read his praise of their musicality here
PRE AMPLIFIER
How an unusual idea turned into a jawdropping experience
Sagatun Mono is a no compromise version of our stereo pre amplifier Sagatun. It has only one channel, so for a stereo system you need two units. Sagatun Mono started as an idea from the corporate advisor of Lejonklou HiFi, who said “You make power amplifiers in mono, why not pre amplifiers?”
The reason why almost no mono pre amplifiers exist is that there is no power involved. And therefore the benefits of splitting the job in two are not so obvious. But my advisor insisted that I should investigate it, mentioning that some enthusiasts have been using two phono stages, but only one channel on each. And after a period of scepticism, I realised he was right; this idea deserved serious investigation. Already on our discontinued single input preamp Kikkin, there was evidence of an improvement by using two units. When finally removing one channel from a pair of Sagatun’s, the experiment turned into a success. Everything that Sagatun does so well on its own is elevated to a new level when reworked into two Mono pre amplifiers.
The technical reasons why the Mono design is superior is the following:
The signal grounds are completely separated. In any stereo amplifier, the left and right signals travel in separate circuits. The more isolated they are from one another, the better it is. The signal grounds, however, either share the same ground planes or join at certain points. By placing each channel in a separate enclosure, there is complete separation of both signal and signal ground.
The chassis grounds are separated. This is a small advantage. When several channels share the same enclosure, there is always a degree of connection between the signals, through components decoupling to the chassis. Separate enclosures prevent this. But it’s important that both power cords are of the same type and connected to the same power strip, to keep the potentials of both chassis’ identical.
The power supplies can run more silently. This is a surprisingly big advantage. As the circuits of Sagatun Mono require approximately half the power of those in the stereo version, the power supplies can be set to an even more quiet running mode. Just like in the stereo version, there are still two power supplies in each unit.
Individual fine tuning is possible. When the two power supplies feed only one channel, further fine tuning of each unit can be made. This elevates performance slightly.
In order to make two Sagatun Mono’s work smoothly together without having to press buttons on both units, a synch protocol with optical transmission called Control Link was developed. It allows one Sagatun Mono – or one stereo Sagatun – to become Master. Other units are Servants, who follow Master. And while the most common usage of Control Link is between two Sagatun Mono’s playing left and right channels, it also allows you to add as many channels as you want. For instance, an extreme 7.1 Home Theatre system can be built using eight Sagatun Mono’s. Or using four Sagatun Mono’s (for Centre, Left, Right and LF channels) and two stereo Sagatun’s (for the less critical surround channels).
Sagatun Mono uses the same simple and intuitive interface as Sagatun. It communicates with a coloured light the volume and input you have selected. One advantage of this interface is that it can be made extremely silent electrically, so that it doesn’t interfere with the music. In comparison, displays are terribly noisy. Another advantage is that it’s very easy to use and can be seen from a long distance, unlike numbers on a display. To get an idea of how the coloured light works, check out the pictures on this page!
In my opinion Sagatun Mono sets a new standard for the musical performance of analogue preamps. If you are currently using a digital volume control in your HiFi, I particularly urge you to give them a listen. A new world of detail and emotion is awaiting you.
Sagatun Mono 1.3 Tarandus was released in October 2016. It’s a new version with improved musicality and a more refined sound.
Sagatun Mono and Tundra Mono were reviewed by Alan Sircom in the UK magazine HiFi+ in the 2017 July issue. Read his praise of their musicality here
