We had MT-601 with one tube, MT-602 with 2 tubes and MT-604 with 4 tubes, which I also own and love it. And finally, the missing model MT-603 has been announced from xDuoo, returning to the beginning with a single, but this time with a 12AU7 Tube.
xDuoo MT-603 has four aux inputs (three RCA and one 3.5mm), and one RCA output. MT-603 features premium Toneluck push button switches. Toneluck is a well-known brand that manufactures switches and OEM parts for many world-famous brands in different categories. They are durable and have a rich feel to them.
xDuoo MT-603 seems a good alternative for those who want to add warm tube sound in their audio circle with multiple inputs.
Specs
High-Quality 12AU7 Tube.
Four Aux Inputs.
One Aux Output.
Toneluck Push Button Switches.
Professional-grade Capacitors for Quality Performance
Frequency Response: 10Hz-40kHz.
THD+N: </= 0.01%.
SNR: 100dB.
Gain: 0dB.
Power Supply: DC12V/2A.
Dimensions: 12×7.8x4cm.
Weight: 0.36Kg.
Price: 109$