TUBE-TECH SSA 2B
Der SSA 2B Summierverstärker verhilft dem Mix am Ende der Audiokette zur analogen Wärme, die man bei einer digitalen Bearbeitung stets vermisst. Der komplett symmetrische Aufbau, die hochwertige Röhrentechnik und die edle Verarbeitung sorgen für eine optimale Summierung aller anliegenden Signale und ergänzen die digitale Studioumgebung auf ideale Weise.
FEATURES & TECHNICAL DATA
The SSA 2B consists of a summing amplifier at the input, a 23 stepped attenuator with a range of +/- 10 dB and an output stage. The summing amplifier is a symmetrical two-stage amplifier, designed around two dual, low impedance, and high transconductance triodes. The input transformer is part of the dual feedback configured as a so-called zero field transformer. The attenuator is a heavy gold plated 2×23 position switch.
The output stage is designed around two dual triodes in push-pull and an output transformer (with a static screen). Both the summing amplifiers and the output amplifiers are symmetrical.
Two large VU-meters show the levels on the XLR output sockets. To avoid the distortion introduced by the VU-meters when connected directly to the output XLR sockets, symmetrical configured OP- amps buffer the VU-meters.
SSA2B Summing principle:
All inputs are balanced by two zero field transformers (one for each channel), but how does a zero field transformer work? In the zero field transformer configuration, 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