Tung-Sol KT170 quartet like new

Tung-Sol KT170 quartet - like new modern power tubes (beam tetrodes) intended for high-end tube amplifiers. They are designed for maximum linearity and high output reserve, ideal for push-pull and ultra-linear topologies in hi-fi and studio applications.

Technical characteristics (Audio tubes)

• Type: Beam tetrode (KT series), glass housing, octal socket (8-pin)
• Max. anode dissipation (Pa): about 85 W (high capacity compared to KT120/KT150)
• Heating: 6.3 V; typically around 2.0A per tube
• Transconductance (gm): typically ~12 mA/V (indicative of high control)
• Gain factor (μ): not a primary parameter for tetrode power; gm and operating point are more relevant
• Typical topologies: AB1/ultralinear, triode connection with appropriate adjustment
• Recommended application: high power amplifiers with adequate power supply and suitable output transformers
• Compatibility: in many builds can replace KT120/KT150 with power check (higher heater current) and quiescent current/bias reset

Sound characteristics

The KT170 is known for its linear presentation with strong macro dynamics and good low-range control. The midrange is clean and stable, the highs are extended without harshness, with low self-noise when the tubes are paired together. Compared to the weaker KT variants, it provides a greater reserve of power and headroom, which is heard as a quieter, more controlled reproduction in demanding passages.

Compatibility and application

Recommended for push-pull AB/ultralinear amplifiers that are designed for the KT series (especially KT120/KT150), with a mandatory check of heater current, anode/screen voltage and bias range. Suitable for modern high-power integrated and power amplifiers, as well as DIY projects with output transformer primary impedances adapted to powerful KT tubes.

Condition and maintenance

Condition: used, excellent (like new). It is sold in a quartet (4 pcs). Recommendation: use in paired channels, periodically check the bias and ensure adequate ventilation for longevity.

Price per piece: 140 EUR