T+A PA 1000 E Integrated Amplifier
The Integrated amplifier
The core of the E-series is the PA 1000 E: an integrated amplifier bursting with power and superb sound. The unit was developed from the legendary Power Plant, whose outstanding sound we succeeded in improving further. The pre-amplifier is a crucial element in determining the sonic characteristics of the amplifier as a whole, and for this reason our development aim was absolute neutrality, superb musical fidelity and outstanding dynamic characteristics. The use of the latest op-amps (operational amplifiers) mounted on discrete, voltage-stabilised circuit boards (OAD = Op Amp Decoupling) ensures absolutely consistent signal processing regardless of load, i.e. uncoloured sound! Naturally there is a two-stage volume control based on a High-End ALPS precision potentiometer to ensure a high overload margin and good signal to noise ratios. A Flat switch is present, which entirely removes the sophisticated tone controls and Loudness function from the signal path.
The PA 1000 E is equipped with high-quality balanced and unbalanced inputs. The balanced input section (XLR) is mounted on its own circuit board, is of fully symmetrical construction, and is coupled directly to the pre-amplifier via differential amplifiers of superb quality. The RCA and XLR inputs are flexible in operation, and can be assigned to different source devices. The input selector switches incorporate gold-contact relays of outstanding quality in order to guarantee freedom from harmonic distortion and background noise.
Basically our new E-series amplifiers are what are known as PWM output stages (PWM = Pulse Width Modulation), with a modulator of analogue construction. Our switching output stages have been developed entirely in-house, and are far removed from ready-made “off the shelf” integrated IC amplifiers; instead the output stages are of discrete construction, equipped with the very latest, ultra-fast MOSFET transistors and intelligent driver modules with high current capacity.
The output stages feature analogue negative feedback, which smooths out the effect of voltage fluctuations in the mains power supply, thereby eliminating signal distortion induced by the power supply voltage; this is an otherwise unavoidable problem in pure “forward concept” circuit designs. However, the negative feedback is relatively weak and frequency-dependent (more pronounced in the bass, where large currents are present, and diminishing in the mid-range / treble). The result is a very controlled, open sound image which never tends towards harshness, characterized by perfectly contoured and well defined bass. The lively, musical nature of this design philosophy is unique.
Switched output stages – if correctly designed – can sound simply wonderful as well as generating tremendous power combined with significantly reduced losses and minimal waste heat.
A particularly important factor in the circuit design is a power supply which is stable under load and capable of delivering high currents. This is necessary in order to deliver energy reliably to the output stages, and not collapse even when the power requirement and peak signals are very large.
That is why the newly developed mains power supply features multiple stabilisation measures, the reservoir capacity of the output stages is high, and the high-performance toroidal transformer is isolated by a floating mount system. The overall result is that the amplifiers can effortlessly drive even power-hungry loudspeakers; after all, the PA 1000 E delivers peak currents of up to 50 Ampere.