The Stax SRM-T8000 amplifier is designed to work with Pro Type headphones (a term that determines the specific polarizing voltage used). This is worth paying attention to – older Normal Type models are not compatible with this amplifier. However, such headphones have not been produced for a very long time. On the left side of the facade there are two smaller aluminum knobs – with one of them you can select the active input, and the second activates the Mute and Bypass modes, if necessary, when the volume control is excluded from the circuit. The latter feature may be useful if for some reason you need to use the source volume control.
The switching arsenal of the Stax SRM-T8000 amplifier includes one balanced input on XLR connectors, two unbalanced RCA inputs and one unbalanced output parallel to input number 1, allowing you to connect the amplifier “in gap” between the source and the pre-amplifier or integrated amplifier of a “large” system. There is also a fourth entrance, which is currently closed with a plug. We can assume that underneath there is an expansion slot into which an optional module can someday be inserted. But today we can only guess about the functionality of such a module. Fantasy throws up the option of a DAC unit with a USB type B or SPDIF input for operating the amplifier directly with digital transports and streamers, or a phono stage module for directly connecting a vinyl record player.
The Stax SRM-T8000 amplifier is built in a fully balanced concept “from input to output” and implements hybrid amplification. The input stage is implemented on a double triode 6922, and the output uses transistors in pure class A. For their effective cooling, cast finned radiators are installed in the central part of the case. To combat vibrations and external interference, special shock-absorbing and shielding casings are used for the lamps of the input stages. The amplifier’s power supply uses a powerful toroidal transformer – this is the first time Stax has implemented such a solution in its amplifiers.
Characteristics Stax SRM-T8000
Type – hybrid headphone amplifier
Frequency response, Hz – 1 – 115,000
Gain, dB – 60 (x1000)
Harmonic distortion, % – 0.01 (1 kHz)
Input impedance, kOhm – 50 (RCA ) / 50 x 2 (XLR)
Maximum output voltage, V – 470 (RMS)
Inputs – analog XLR, analog RCA (2)
Outputs – analog RCA, five-pin jack on the front panel for connecting headphones (2)
Power consumption, W – 95 W
Additionally – slot for optional expansion modules
Dimensions, cm – 32.0 x 10.3 x 39.5
Weight, kg – 7.3
