DS Audio TB-50 Tube Phono Equalizer

Hybrid EQ amplifier with vacuum tube buffer
The DS Audio TB-50 tube phono equalizer uses a hybrid architecture that pairs semiconductor‑based amplification and equalization with a vacuum‑tube buffer in the final output stage. The result is the ideal combination of precise, stable signal amplification from semiconductors and the rich harmonic character associated with vacuum tubes. It employs the same ECC82 (12AU7) tube used in the flagship TB‑100, allowing DS Audio to bring its signature tube sound to a wider audience.

Duct structure for efficient tube heat dissipation
A dedicated duct structure surrounds the vacuum tubes, drawing in fresh external air and expelling heat efficiently. This maintains a stable internal temperature, ensuring the tubes operate at their optimal point even during long listening sessions. The result is consistent, reliable sound quality and improved long‑term performance.

Ideal cartridge connection through current drive and current transmission
The amplifier uses a current‑drive/current‑transmission method to power the cartridge and carry the audio signal. This approach is far less affected by phono cable characteristics or connector quality than traditional voltage transmission. By minimizing the influence of cable length and contact resistance, it achieves the ideal connection for extracting the full performance potential of DS Audio’s optical cartridges—exactly as the company advocates.

Adjustable vacuum tube illumination
An LED illumination system beneath the vacuum tubes allows the brightness to be freely adjusted to match your listening environment or aesthetic preference. The rear‑panel control provides smooth, stepless adjustment, balancing functional visibility with visual appeal.

Specifications

Rated output voltage: 500mV (1kHz)
Input terminals: RCA terminal
Output terminals: RCA terminal
Output impedance: Approximately 700Ω
Dimensions: W420 × H120 × D320 mm (including terminals)
Weight: 11.3kg