Предусилители — T+A P 3100 HV

The P 3100 HV is the analogue control unit in T+A's HV range and succeeds the P 3000 HV. It is a discrete, fully symmetrical design built without any op-amps, and its stages are DC coupled, so the audio passes through no coupling capacitors between input, volume control and output.

Key specs that matter

Seven unbalanced RCA inputs accept 250 mV to 9 V at 20 kOhm, and four balanced XLR inputs accept 500 mV to 18 V at 5 kOhm. The RCA pre out delivers 1 V nominal and up to 9.5 V, the XLR pre out 1.45 V nominal and up to 19.6 V, both at 50 ohm. A recorder output supplies 250 mV at 100 ohm, and a high current headphone output has 50 ohm impedance. Frequency response runs from 0.5 Hz to 300 kHz at +0/-3 dB, with S/N quoted at 108/112 dB, while harmonic distortion and intermodulation are each rated below 0.001 %. Channel separation exceeds 108 dB, and the circuit handles 80 Vss without distortion. The case measures 17 x 46 x 46 cm and weighs 28 kg.

Engineering and use context

The two channels are built in double mono form, and the circuit boards are shielded inside an aluminium compartment with walls 10 to 15 mm thick, kept completely apart from the power supply section. Compared with the P 3000 HV, the whole preamplifier section was reworked, replacing capacitive coupling with pure DC coupling, and a new board layout compensates for the temperature coefficients of the transistors to keep the circuit stable. Volume is set by a relay control. Gain stages use a differential cascode topology with hand selected J-FET transistors. Power comes from two mains inputs, rated at 10 and 60 W, with an oversized toroidal transformer enlarged to 115 VA, improved shielding of the digital supply and 75,000 uF of reservoir capacity, while standby needs less than 0.5 W. Finishes are silver lacquer 47 or titanium lacquer 64 with a black heat sink, and an F 3001 remote control is included.

Pairing

An optional phono module can be configured for MM or MC cartridges, and input 4 can be set to a surround bypass mode for integrating a multichannel processor. A trigger input for +5 to 20 V handles external switching. Matching power stages from the series are the A 3100 HV stereo power amplifier and the M 40 HV mono power amplifier.

Alternatives

The T+A PSD 3100 HV is the HV series preamplifier that adds a streaming client, a DAC with separate PCM and DSD converters, HDMI inputs and FM and DAB+ reception.