Rectification of the plate voltage is done by 4 TV-damper tubes in a full wave bridge arrangement. These tubes had been developed to suppress spikes in TV sets caused by the fly back of the electron beam in the picture tube. They are also perfect for rectification purposes. Smoothing of the rectified voltages is always done purely passive with multiple chokes and capacitors. The chokes are also made by Lundahl. The capacitors are NOS paper in oil types of the American company Sprague. Filament voltages are provided in a similar fashion, but with Schottky diodes for rectification. This is why the power supply chassis alone weighs about 20kg.

Both components are connected by a screened umbilical. Inside the preamp chassis the high voltage is decoupled between the chassis by LC-Filters. If the olive green of the connectors remind you of the army, you are right. The Amphenol connectors are made for military and industrial use.

And how does it sound with this preamp in the system? This actually proved to get quite difficult. It is always easy to describe a preamp with certain flaws or a specific tonal character. But what if you can’t find anything like that? For such cases I have a special record to assess the sound very easily. It is a record with my daughter. She sings ‘Angel Eyes’ from Matt Dennis. She sings solo straight into the recorder. No fancy equipment and the recording also has a slight hum. Dirk Sommer would probably tear his hair. Since I am very familiar with her voice, this allows me to hear very quickly if the reproduction sounds like my daughter or not. And I can say I never heard this recording so authentic as with the 10Y! To describe this in HiFi terms: The articulation of the voice improved dramatically without impacting other aspects, for example increased presence. This preamp also shows that directly heated triodes are able to reproduce voices with a certain magic. Which doesn’t mean that my daughter sounds better through the amplifier than in real life.

This recording is very special and wouldn’t reveal as much to another person as it does to me. Therefore I’d like to continue with a Mozart recording by Claudio Abbado and Martha Argerich.

This CD was recorded last year during the festival in Luzern. It contains two piano concertos of Wolfgang Amadeus Mozart. Here we have two very different personalities. The considerate maestro Abado who meets a spirited Latina. Mozart is not exactly the strength of Italian conductors. Their interpretations can have a tendency towards easy listening. But this recording does not meet this cliché, it has a lot of substance thanks to the fulminant style of La Martha. The preamp immediately uncovers an issue with the sound of the orchestra. It tends to break up into the groups of instruments. Difficult to say if that has been caused by the conductor or the recording. The 10Y uncovers this blatantly. The piano on the other side has a three dimensional presence in front of the orchestra. The attack of the keystrokes is reproduced with impact and precision. The 10Y reproduces this recording with more depth than width.

Next we listen to John McLaughlin with Kai Eckhardt and Triok Gurtu. This recording was done 1989 in the Royal Festival Hall in London. 1989 was not yet a great time for digital recordings but this one is not bad at all. The 10Y uncovers more from the bits as heard before. For example Kai Eckhardt with his Schack-Bass. During that time headless basses were popular. Eckhartd also plays such a headless instrument with a carbon shaft. This gives a wiry, slightly sterile sound which had not been audible so clearly with other preamps. The slaps come with power and precision, an advantage of this construction style. Also very audible that McLaughlin is not playing the acoustic guitar with his fingers but uses a plectrum. The guitar is very three-dimensional. This was not audible before and was always attributed to the recording quality.

There is a new, brilliant recording of Beethoven’s Diabelli variations with the Hungarian Andras Schiff who didn’t want to do the hundredth variation of this composition. Besides his exquisite playing technique he came up with something special. He played the variations on a Franz Brodmann hammer piano from 1820 and in addition on a modern Bechstein from 1921. This was not done for HiFi purposes but to show how this music would have sounded on a contemporary instrument of Beethoven’s time. But his recording can be nicely used for HiFi comparisons. Of course I have listened to this recording through various equipment and I was well aware of the different characteristics of the instruments. With the 10Y, listening to the hammer piano turned into a time travel experience. The subtle tone colors of the hammer piano get transported very nicely. This instrument has less volume with richer over tones, a bit more dry sounding compared to modern pianos. These differences are not that apparent when listening with other set ups. Often it goes unnoticed that another instrument from a different time is played on the second CD, which looses an elementary intention of this recording. The instrument is clearly projected and becomes almost physically present in the room. Great!