T+A PA2500 R Integrated Amplifier

The Integrated Amplifier

Twice as tall, higher output power and even more connection facilities – the PA 2500 R exceeds the specification of the PA 2000 R in many areas, but its character in terms of sound quality is in no way inferior to its smaller sibling. This by no means goes without saying, because very powerful amplifiers often forfeit the finer points of dynamics and detail tracery. Our PA 2500 R integrated amplifier circumvents this danger: its basic circuit is the same as that of the PA 2000 R, and even the circuit board layouts are identical. However, its heat-sinks are twice the size, and the case accommodates two of our new high-performance mains power supply units, with the result that it can deliver more than 280 Watts of continuous power per channel into 4 Ohms loudspeakers. The amplifier is therefore effortlessly capable of controlling speakers which are extremely critical in terms of phase and impedance. The PA 2500 is even more powerful than the smaller machine, but retains exactly the same dynamism and cultured sound.

Technology

The quality of any output stage is deter­mined to a very great extent by the mains power supply as well as the circuit topology. Mains power supply units must be as stable and resilient as possible, to ensure that the voltage they generate does not collapse even when very high peaks are encountered. In conventional equipment this requires very large transformers, but the limited space available in the low-profile R-series machines spurred on our en­gineers to develop an ingenious alternative solution: a regulated high-frequency sine-wave mains power supply with generous reservoir capacity, capable of delivering up to 1200 Watts without problem. The mains power supply can deliver very large quantities of current extremely quickly, even when the gradient of the peak signals is steep. Our experience in building amplifiers over a period of thirty years has taught us the importance of the quality of audiophile modules for the final outcome in terms of sound quality, and that is why we choose our components with great care and then select them according to strict criteria, to ensure optimum characteristics for each specific application.

We use low-loss mica capacitors with silver electrodes, zero-induction resistors, precision low-noise audio resistors, and nickel-free gold- or rhodium plated terminals specially manufactured for T+A. Many of these components were developed for military applications, and therefore fulfil exacting requirements in terms of quality and durability.All the electronic circuitry for controlling the machines is recessed into the solid aluminum front profile, where the shielding effect is outstanding. The front panel features a bright, dimmable screen (VFD) and control knobs with variable lighting. Another in-house development for the latest R-series is a completely new and very fast data bus for data exchange between the devices, which makes it possible to control a whole system with a single remote control handset. Alternatively, if the system includes an MP 2000 R, the equipment can be controlled using the T+A App for iOS or Android. Both amplifiers are equipped with a sophisticated protective circuit which is situated outside the signal path, and therefore cannot possibly have any adverse effect on sound quality. The protective circuit constantly compares the input signal before the output stage with the output signal, and instantaneously switches off the output relays if it detects the slightest deviation (clipping, distortion, etc.). The protective circuit is also triggered if overheating occurs, or if a short-circuit is present at the outputs.