Tube Tech SSA 2B 20 Input Tube Summing Amplifier

• 10 Stereo inputs - 1 stereo output
• Stereo inputs 1 and 2 can be switched as 4 mono inputs
• Zero field transformer balanced inputs
• Frequency response @ -3 dB: 5 Hz – 100 kHz
• Low noise: < -85 dBU @ all inputs terminated
• CMRR: > 60 dB @ 10 kHz
• Distortion < 0,05 %
• 23-step gold plated output gain control
• Master output gain: -10 dB to +10 dB
• Fully symmetrical circuitry from input to output
• Maximum input < +30 dBU
• Two large VU meters show output level
• Gold plated switches
• Outputs are transformer balanced and fully floating

The Tube-Tech SSA 2B Stereo Summing Amplifier features two very low noise / low distortion summing amplifiers with a very wide frequency response. The inputs are transformer balanced and the circuits are symmetrical from input to output. The inputs are capable of handling extremely high input levels. The outputs are balanced and have fully floating transformers with a static screen. The power supply and the side chain circuits are based on a solid-state circuit. With the exception of the output stage all DC voltages are stabilized.

SSA2B Summing principle:
All inputs are balanced by two zero field transformers (one for each channel).

What is zero field transformer?
In the zero field transformer configurations, the transformer is part of the feedback circuit. There are several benefits for this:
1. The voltage across the transformer is reduced substantially whereby a much smaller transformer is needed for the same specification. The reduction is of the same magnitude as the feedback applied.
2. The distortion at low frequencies is reduced substantially.
3. Frequency response in both the low and high range is extended.
4. Phase response in both the low and high range, is also reduced


For more information on this or any Tube Tech product, visit www.tube-tech.com.