AVM PH 8.3 Reference Tube Phono Preamplifier

PH 8.3 Reference Phono Stage

The PH 8.3 is AVM’s reference tube phono stage. The versatile PH 8.3 provides record lovers with world-class sound quality, whether they have 50 LPs or 5,000. It combines the sweet musicality of AVM’s exclusive 803T dual triode vacuum tube with cutting-edge flexibility and control.

The PH 8.3 come complete with three inputs: MC XLR, MC RCA and MM RCA. Cartridge loading is completely adjustable via remote control. Users can also remotely select from five different equalization curves in addition to the RIAA standard, maximizing performance from vintage records. Circuitry is fully DC-coupled, and is paired with five separate power supplies and all-passive equalization, ensuring that performance is stable and unaffected by even the most demanding desert island discs.

AVM PH 8.3 Technology

The PH 8.3 equalizes the phono signals purely passively and analogously and not in an amplifier stage. This has the advantage that each of the three time constants can be set individually. This makes it possible to use 5 other common LP equalizations (RIAA, TELDEC, NARTB, EMI, COLUMBIA, DECCA) in addition to the RIAA curve that is widespread today. These curves differ in the corner frequencies & time constants used when cutting the record. These separation characteristics are inverted by the PH 8.3 with an accuracy better than +/- 0.1 dB. We achieve this extreme accuracy through the complex matching procedure of the built-in resistors (matched to 0.1%) and the film capacitors (matched to 0.5%).

With the switchable subsonic filter, rumbling noises can be effectively dampened (30Hz/12dB/octave).

The level (gain) can be adjusted in 5dB steps to measure different pick-up systems. Mono/stereo and the phase can also be inverted for the best sound measurement and for older recordings. All adjustments or settings can be conveniently made from the listening position using the remote control supplied and are also saved automatically.

On the input plug-in cards, the incoming signals are amplified immediately after the input at line level (approx. to 150mV), with MM by 40dB, with MC by 60dB. All equalization or adjustments are then made with these greatly enlarged signals, so the distortion components of all subsequent stages are far less important in comparison. Up to 4 different inputs can be equipped as desired, so any combination can be selected from the following input modules: MC XLR (balanced), MC RCA, MM RCA. The PH 8.3 automatically recognizes which modules are plugged into which slots or as combinations and adapts all functions such as the menu structures. The inputs can also be named individually. Inputs are galvanically isolated from each other.

The effort is also immense for the power supply: 5 independent power supply units supply all stages of the PH 8.3 individually and effectively exclude unwanted mutual interference of the amplifier stages by other assemblies. The silent switching power supplies deliver high-precision supply voltages, practically independent of the mains voltage. In contrast to large transformer power supplies, no acoustically negative magnetic fields are generated with these power supplies.