Herron Audio VTPH-2 - Design Considerations; Key Features and Circuit Design

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VTPH-2 Vacuum Tube Phono Preampliﬁer Owners Manual

• Two operating modes: Moving Coil and Moving Magnet

• Separate RCA input connectors for Moving Coil and Moving Magnet

inputs

• Additional RCA connectors for external Moving Coil loading

• Moving Coil/Moving Magnet mode switch

• 15 second mute during mode change

• Cartridge bias Moving Coil input stage allows for inﬁnite load resistance

(operation with cartridge unloaded)

• All-tube signal path (moving magnet mode)

• Passive RIAA equalization for accurate phase and amplitude response

• Available in two factory set tube conﬁgurations

• Class A operation

• Star grounding for low interference susceptibility and clean signal path

• Zero feedback—no feedback loops in the audio circuitry

• Low noise

• High input signal capacity without overload; see technical speciﬁcations

• Gold plated RCA and ground connectors

• Audio path capacitors are high quality metal ﬁlm

• Hand-picked components for accurate response

• Automatic muting at startup and shutdown

• 78,000 mF of power supply energy storage capacitance

• 4 levels of high voltage regulation

• Regulated soft-start DC ﬁlament supply

• Regulated tube bias supply

• Toroidal power transformer

• Reversing power line (AC) polarity switch for minimizing line-to-chassis

reactive currents and noise pickup

• Controlled warm-up of tube ﬁlaments and high voltage for extended

tube life

• Low plate operating currents for extended tube life and cool operation

• Front panel indicators for power, voltage, and output (mute release)

• Each unit is given a 48-hour burn-in, including rigorous bench and

listening tests

Design Considerations