P 3100 HV Preamplifier

P 3100 HV Preamplifier
Preamplifiers are the most important components of any high-end audio system. Connected source devices deliver low-level signals to the preamplifier’s input section, where the signals are selected, amplified, volume-controlled, processed where necessary, and routed to the output stage for delivery to the power amplifiers. All of these functions must be performed without altering or compromising the integrity of the original signal.

T+A has invested extensive effort in developing preamplifiers that fully meet these requirements. The units feature a discrete, fully symmetrical design, with every component selected from the finest available technologies. The circuitry is housed in uncompromisingly engineered enclosures designed to provide optimal operating conditions.

The design concept of the P 3100 HV is based on the P 3000 HV. Externally, the only visible difference is the model designation. Internally, however, the entire preamplifier section—the most critical part of the unit—has been further refined and enhanced.

In the P 3000 HV, the input and output stages were coupled to the relay-controlled volume system via high-quality capacitors. In the P 3100 HV, a newly developed and highly sophisticated circuit-board layout compensates for transistor temperature coefficients and allows the operating points to be adjusted with exceptional precision. As a result, the preamplifier stages are fully DC-coupled. Coupling capacitors are no longer required in the signal path between the input stage, volume control, and output stage.

The preamplifier board is exceptionally stable with regard to both voltage and temperature. In addition, T+A has increased the capacity of the digital power supply and further improved its shielding. The already generously specified toroidal transformer serving the analog section has been enlarged to 115 VA. Together, these enhancements result in a significant improvement in overall sound quality.

The ingenious overall circuit design of the HV (High Voltage) series, developed by T+A, operates all amplifier stages at significantly higher voltages than conventional designs. In the preamplifier, operating voltages reach up to 100 volts, while the power amplifier operates at up to 360 volts.

Similar to the principles employed in valve amplifiers, the actual signal modulation within each stage remains exceptionally low. Less than 20% of the available excursion range of the amplifier transistors is utilized, virtually eliminating the effects of characteristic curve non-linearity. Additional measures are implemented throughout the design to further enhance the linearity of the voltage amplification stages.

In addition to outstanding linear performance, the elevated operating voltages provide an exceptionally wide dynamic range. T+A developed this unique technology for use across the entire HV series because of the substantial sonic benefits it delivers. These advantages can be realized not only in preamplifiers and power amplifiers, but also in the output stages of source components such as the MP 3100 HV multi-source player.

The rear-panel connector section clearly demonstrates the P 3100 HV’s uncompromising design philosophy and fully symmetrical dual-mono architecture. The left and right channels remain completely separated throughout the signal path. The preamplifier circuit boards are identical in construction and are positioned beneath the upper section of the enclosure, a layout specifically designed to minimize electromagnetic interference.

Each circuit board is housed within its own compartment, constructed from thick-walled aluminum plates measuring 10 to 15 mm in thickness. These compartments provide complete physical and electromagnetic isolation from the mains supply and power supply assemblies located in the lower section of the chassis.

The circuit topology is based on a differential cascode amplifier design utilizing hand-selected audio-grade JFET transistors. All amplification stages are fully discrete and operate without the use of operational amplifiers (op-amps). Rather than relying on heavy global negative feedback, as is common in conventional op-amp-based designs, linearity is achieved through the quality of the circuit topology, the precision of the selected components, and meticulous adjustment during production. As a result, only minimal overall negative feedback is required.

T+A HV technology enables the processing of signal levels up to 80 Vpp (peak-to-peak) without distortion—a performance level that remains exceptional for a transistor-based preamplifier.

Preamplifier stage

• Frequency response + 0 / – 3 dB:   0,5 Hz – 300 kHz
• Signal / noise ratio:   108 / 112 dB
• Total harmonic distortion:   < 0,001%
• Intermodulation:   < 0,001 %
• Channel separation:   > 108 dB
• Unbalanced inputs (RCA):   7 x 250 mVeff ... 9 Veff / 20 kOhms
• Balanced inputs (XLR):   4 x 500 mVeff ... 18 Veff / 5 kOhms

Outputs

• Headphones:   50 Ohms high current
• 1 x Recorder:   250 mVeff / 100 Ohms
• PRE out RCA:   Nom 1 Veff, Max 9,5 Veff / 50 Ohms
• PRE out XLR:   Nom 1,45 Veff, Max 19,6 Veff / 50 Ohms
• Reservoir capacity:   75000 μF

Mains / Accessories / Dimensions

Mains:   

• 2 x 110 - 120 V/60 Hz or 220 - 240 V/50 Hz, 10 + 60 Watts rated current consumption

Standby:   < 0,5 W

Features:   

• Trigger input +5 ... 20 V for external switching-on input 4 can be configured in surround mode analogue signal processing module slot for optional phono

Remote control:   F 3001

Accessories:   2 x power cord, remote control receiver E 2000

Dimensions (H x W x D):   17 x 46 x 46 cm

Weight:   28 kg / 61.7 lbs

Finishes:   Case: Silver Laquer 47 or Titanium Laquer 64, Heat Sink Black 42

Technical modifications reserved