This is a self-made vacuum tube amplifier from a considerable age. When I turned it on, there was a buzzing noise (probably only from the right side?). I suspect it's a faulty electrolytic capacitor (the back was bulging). I don't have the knowledge to repair it, so I'm putting it up for sale. There are also photos of the back cover opened, so please take a look. For those who can maintain and service it, please. The vacuum tubes are 4 EL34s, 4 12BH7As, and 4 12AX7s. The manufacturer is unknown. (Some have "USA" and "JAPAN" markings.) It appears to use 1 TANGO transformer and 2 LUXMAN transformers. I don't know the model numbers, so please check the images. I haven't tested the vacuum tubes, so there's a possibility they are defective. Please understand this before purchasing. It's quite large and heavy, so shipping will be cash on delivery. I will pack it securely. P.S. I mistakenly uploaded a photo with the vacuum tubes inserted incorrectly. I did not turn it on in that state. I have uploaded additional photos. Please check the 11th photo for a sense of the size.