i am using an musical fidelity trivista 21 tube dac limited to 1500 pieces. built like a tank with 2 toroidal and 2 regular transformers.
it has 5703w tubes lasts for 100000 hours. compared it with denafrips terminator and gustard x26 pro and holo audio l2 . no usb or i2s
musical fidelity but outperforms in every aspect timbre tone and bass slam.but newer dacs sounding thin relatively. so hunt for older dacs.imo
trivista 21dac can change sound quality by rolling opamps which i will be trying soon. if any one has the chance get it from uk and taste the sound of it