YOSHIBA Onkyo
MODEL KLV-66 Monaural Tube Power amp

Yoshishiba Acoustics, the developer of this amplifier, says, "This monaural amplifier is a great evolution of Yoshiba's amplifiers. This amp is so confident that Yoshishiba's sound has changed a lot.

We want people who have no experience with tube amplifiers and people who are thinking about starting audio to enjoy it easily, and even if it is not stereo but monaural, or rather, because it is monaural, you can enjoy it so much! This one unit is enough! The MODEL KLV-66 was designed as a low-priced monaural amplifier with this in mind.
The power amp also comes with volume and equalizer controls, so you can connect it directly to your music player and enjoy your music.

One speaker is better than the other.

The impression I got by connecting speaker cables for two speakers to one set of speaker terminals on the amplifier side was that the bass had a core and sounded much better than I had imagined. Female vocals are also very satisfying to listen to. Above all, the sound impression I got even though I was not using a particularly good CD player was wonderful.
Next, I tried listening with one less speaker; the sound was clearer and the overall sound had more punch and push than with only one speaker connected. That seems to be exactly what Mr. Yoshishiba is trying to achieve. The frequency response is relatively flat and narrow in terms of numbers, but the middle range is rich, the highs are extended, and the lows seem to sink in even more. It is good that listening to music for a long time is not more tiring than listening to music on a normal stereo.

As is the case with all Yoshishiba Acoustics amplifiers, the amplifier is made even more comfortable to listen to by taking the time axis into account and correcting the misalignment that occurs during playback.
MODEL KLV-66 is a vacuum tube monaural amplifier that, while meticulously ordered and designed, strongly reflects Yoshishiba's commitment that sound is not all about numbers and data.
If it is this good, you may be tempted to try stereo mode with two KLV-66s.

Furthermore, the KLV-66 has a volume control, so even those without a preamplifier can connect a CD player or other device directly to the KLV-66 and enjoy it. Moreover, it has an equalizer function to control the high and low frequencies, which is heartbreaking. According to Mr. Yoshishiba, "The bass sounds great.
Connecting to two speakers

Connecting only one speaker

Tubes used	6V6 x2, 6SQ7 x1, 5Y3 x1, 6SL7 x1
Frequency response	20Hz-15kHz, +/-3dB
Transformer used	Output: Yoshishiba Acoustic Original Power supply: Custom-made transformer
Output: Custom-made transformer	10W
Speaker output terminal	8ohms, 16ohms
Power supply	100V, 120V, 220V, 230V/50,60Hz/80W
Size	W180 x D390 x H170mm
Weight	8.2kg