Tube Box DS3 B

The Tube Box DS3 B is a dual mono phono stage that adds balanced inputs and outputs to Pro-Ject's tube phono preamplifier line. It uses two E88CC / 6922 tubes in the output stage, and the circuit design comes from Dr. Sykora. It is handmade in Europe and comes in silver or black.

Two turntables can be connected at once, and the settings for each input are set on the front panel and stored in memory. Gain is selectable from 40 to 65 dB in 5 dB steps, which suits a wide range of cartridges and lets the level be matched to other sources. Load impedance is adjusted continuously with a potentiometer, so changes can be heard during playback. Capacitance can be switched between 50, 150, 300 and 400 pF.

Inputs are a 5-pin mini XLR, a pair of XLR and a pair of RCA phono. Outputs are a pair of RCA and a pair of XLR. Balanced connection carries the signal as hot and cold phases, which cancels noise picked up along the cable. A subsonic filter at 20 Hz is built in, and power comes from an external 18 V DC supply.