I will add my pennies to the discussion about the sound, those amazing HiEnd amplifiers that were produced by the Sansui company, and whose sound I read here a very interesting discussion and valuable comments.
During the last time of the corona virus pandemic, I had all the Sansui tips of the MOSfet series at home: B-2102MV, B-2103MV, B-2105MV and compared to the B-2301L on the Sanken LAPT.
Initially, I conducted comparisons with the pre C-2301, in all cases, but I got the impression that such extended systems with additional pre + cables "conceal" the delicate differences between the individual terminals. Subtle differences "blur". That is why for detailed comparisons I used the Ayon CD, with a built-in DAC and quite neutral pre, to ignore the influence of additional elements, such as additional cables. I must emphasize that when changing the cables in such a reduced system: CD - power amplifier - loudspeakers, each change of cables was very noticeable and strongly influenced the change of the range transmitted by the band systems.
Comparisons made on my system:
The first remark, as it appears straight away, is that all MOSfet power amps sound much softer than the B-2301L power amp on the LAPT. In the case of the 2301L, the sounds are not as "velvety" and "warm" as those containing the MOSfet.
Second note. Out of all the MOSfet terminals, the most similar to the top B-2301L in terms of the transmitted bandwidth range from Hz to kHz, seems to be the B-2103MV, playing the most even, "neutral" band, similar to the 2301.
Third note. Each of the B-2102MV, B-2103MV and B-2105MV terminals plays in a different frequency band.
B-2102MV
It has a very nice stage, extended sideways, up - down and down. It sounds with a strong bottom and midrange, but has a softer than the other two, the most light and "velvety" treble. This, however, in my opinion, is its huge advantage, as it makes only this power amp so deeply extended to the soundstage. This tip builds an incredible depth to the stage. That is why, in my opinion, it also has a very detailed bottom end, in which individual sounds do not merge into a uniform bass mass. All additions, plates, cicadas, etc. "disturbances" and embellishments are very delicately sounding but perfectly audible. What is important to me is that they do not disturb, drown out the melody, and do not distract from the enjoyment of listening to music.
B-2103MV
It plays very well. In this power amp, in my opinion, the influence of the MOSfet is the least audible and very, for the first time, it resembles the sound of the AU- @ 907XR, if you have it fresh in your memory. However, when you hear it for the first time, you get the impression that it makes a very "velvety" sound in relation to the aforementioned Alpha.
The sounds in the B-2103MV are distributed evenly across the speaker line. The scene is built slightly deeper. The deeper the better, the better the quality of the listening CD. Here the details, which are the responsibility of the midrange and the upper part of the frequency response, are much better audible, but not with such intensity that it degrades the sounds and interferes with listening. This, however, makes the stage much shallower than can be seen in the case of the B-2102MV.
B-2105MV
It plays with the range most shifted towards the upper part of the band - the most "bright". This probably makes the soundstage seem shallow, but the sound comes out towards the listener.
This is the ending with the most resonant scene. You will hear very extensive various hums there. First impression - as if you found yourself in a huge cathedral. There are sounds from all sides. "WOW" effect! The game is amazing! However, for me, such an extensive scene is rather unbearable. The sounds detach from the speaker lines, and you feel like you are immersed in the sounds. After a while, the sound overwhelms!
Maybe its time to bring out the 907LTD again into my main room... it's been sitting in the bedroom for over a year.
