Pre/Power Amplifiers

While the P 3100 HV is clearly an evolution of the 3000 chassis, the 'genetics' of this fully discrete design remain unaltered. Key to this is the HV or 'High Voltage' preamp topology where specially selected J-FETs run at uncommonly high, up to 100V, PSU voltages. With only a very small proportion of this 'swing' used in practice, this allows T+A to operate the FETs in Class A over a limited but highly linear portion of their range. The result is distortion that's largely unchanging with either output or frequency without employing anything more than the absolute minimum of corrective feedback.

Achieving the desired complement of harmonic distortions – typically just 2nd-order – was as important to T+A's engineers as the level of THD itself, although at just 0.00005% through the critical midband, distortion can only be described as vanishingly low. T+A has also rid the P 3100 HV of some interstage coupling capacitors, moving to a DC-coupled design without falling back on DC-servo offset cancellation. Instead, the likelihood of DC drift is countered by precise thermal coupling of the FETs combined with painstaking manual adjustment of all stages. PM