T+A P 3100 HV Preamplifier Lab Report
If the technical prowess of T+A's flagship preamplifier was never in doubt [HFN Sep '14] then this latest P 3100 HV iteration pushes and polishes the performance still further. Once again, it offers a maximum +14.3dB gain (balanced) with a custom volume control that acts in 1dB steps over a 60dB range with ±0.1dB overall accuracy, over an 80dB range with ±0.2dB accuracy and 90dB with just ±0.3dB variance – this is a very tight tolerance indeed and matched by very few other preamplifiers. Distortion, meanwhile, inches downwards further still from a minuscule 0.00007-0.00025% to 0.00005-0.00024% here [20Hz-20kHz re. 0dBV – see Graph 2, below] while maintaining its wide 102dB A-wtd S/N ratio and very low –99.1dBV (11µV) residual noise. Maximum output is a prodigious 17.5V – driving any power amp on the planet – while the input overload is >12V.
Arguably, the most significant change to the design of the 3000/3100 lies in the removal of all but one coupling capacitor while stabilising the DC performance of the preamp without recourse to a servo. So, where the output impedance of the P 3000 HV 'increased' from 45ohm (100Hz-20kHz) to 47ohm at 20Hz, the P 3100 HV's source impedance remains flat to within ±0.1dB from 20Hz-100kHz. Moreover
while the HF response of both preamps extends to –0.02dB/20kHz the 3000's 'dip' in low frequency response to –0.5dB/1Hz is absent in the P 3100 HV which is flat to below 1Hz [see Graph 1, below]. While this adaption in frequency response will not be audible per se, the elimination of DC-blocking caps and absence of a DC servo may well exert some subjective benefit at very high as well as very low frequencies. PM
Maximum output/input (<1% THD) | 17.5V (balanced) |
Output imp. (20Hz–20kHz/100kHz) | 44-45ohm / 45ohm |
Frequency resp. (20Hz–20kHz/100kHz) | +0.00 to –0.02dB / –0.45dB |
Input sensitivity (re. 0dBV) | 190mV |
Input overload | 12.5V (balanced) |
A-wtd S/N ratio (re. 0dBV) | 101.8dB |
Distortion (20Hz-20kHz, 0dBV) | 0.00005–0.00024% |
Power consumption | 49W (analogue PSU) / 5W (dig) |
Dimensions (WHD) / Weight | 460x170x460mm / 28kg |
Price | £12,690 (Phono module, £1088) |