This is the hidden gem Luxman MQ68 Custom amplifier. Luxman amplifiers of this era, such as the SQ38FD and MQ60, were famous for using the 50CA10 vacuum tube, jointly developed with NEC, as the output tube. Naturally, this vacuum tube amplifier also uses the 50CA10 (Luxman logo). However, it seems that they wanted to improve the bare characteristics, as they felt that using the same circuit as the previous MQ60 would not be fresh, and it was released around 1978, just before 1980. Power transformer: lux S-1747 Output transformer: lux OY15-6KHP Choke coil: C-1744 First stage: 6267 EF86, new Russian dead stock The second stage phase inverter originally used 6240G, but it is no longer in production and unavailable, so Hitachi's 6CG7 (6FQ7) is used as a substitute. As you can see from the internal photos, the wiring is of very high quality. There are no cramped areas, and I felt that the spaciousness and well-thought-out wiring and layout had evolved. Therefore, the modifications I made were limited to: Changing the routing of some wiring, replacing capacitors including coupling capacitors, restoring the contacts of the volume control and replacing some volume controls, and bias adjustment. The bias is set as low as possible to extend the life of the 50CA10, so please readjust it if you are concerned. A 10Ω resistor is inserted, so you can read the value from the cathode using a tester. A note of caution: This is a common mechanism in Luxman vacuum tube amplifiers of this era, and the power will not turn on unless the bonnet is attached. There are scratches and dirt commensurate with age; please check the images. https://youtu.be/IJYErT4tVbc?si=UlqCj-uA079DAPFs As this is a private sale, please refrain from after-sales support and detailed questions. Discrepancies are inevitable regarding subjective matters such as noise when silent and the appearance of scratches and dirt. Please be sure to check the description, video, and images posted and agree to the terms. In principle, no claims, no returns, and no cancellations are accepted. Please refrain from purchasing if you are a perfectionist or expect the same condition as a new product from the manufacturer. Please purchase only if you understand that this is a used, manufactured, and vintage item.