The P-7100 inherits technology features and concepts of the 40th anniversary commemorative model A-200 and subsequent M-6200 and takes these even further. Some of the highlights are a drastic reduction in noise and a significant further improvement of the damping factor. In the final stage, the parallel configuration of output devices ensures high current capacity and keeps the output impedance of the power amplifier extremely low.
In addition, intensive research has culminated in an improved NFB loop with remote sensing, and the use of MOS-FET switches characterized by low ‘on-resistance’. This further improves the ability to handle any speaker with competence, realizing constant-voltage drive even with extremely low load impedances. The guaranteed damping factor of at least 1,000 demonstrates the impressive success of this approach. In addition, by further refining the parallel drive and gain allocation of the input stage, Accuphase engineers were able to push the noise floor to previously unthinkable levels, achieving an amazing signal-to-noise ratio of 125 dB at maximum gain and 131 dB at the12 dB gain setting. The massive aluminum diecast heat sinks arranged on the left and right side of the amplifier are in direct contact with external air to maximize heat dissipation efficiency.
4-stage gain selector (12 dB,6 dB, 3 dB, MAX) directly controls the gain of the instrumentation amplifier and therefore further minimizes residual noise at lower settings.
Large high-power toroidal transformer
The P-7100 features a newly developed massive high-power toroidal transformer, enclosed in an aluminum housing with excellent thermal conductivity and superior vibration damping characteristics.
Filtering capacitors with high capacitance
As in the A-200, two generously dimensioned vibration resistant aluminum electrolytic capacitors of 56,000 F each are used, to provide ample smoothing capacity. The capacitors have been specially selected for their excellent sonic properties.
To reliably protect the speakers from any risk of damage in
case of an amplifier problem during operation, power MOS-FET devices with an on-resistance as low as 0.002 ohms are used. Because these semiconductor switches do not have any mechanical contact points, there can be no contact failures and excellent long-term reliability is assured.