The chinese tubes that come with it are marginal at best. It sounds brittle with them. It is a totally different piece with NOS tubes. Very detailed, but with the right tubes, no etch or grain. Strings, especially cellos and double basses are especially rich in tone and detail.
Acoustic material is the true test and is wonderfully rich.
Ganged volumn control not totally linear from low volumn to high and a bit of a hassle to use. It's no beauty. With the new tubes the sound is addictive. Class A front end with a very nice tube sound. I don't necessarily prefer tubes, I like an accurate sound by whatever means available.